Merge pull request #176 from phi-gamma/texlive2014

sync with Context, wipe out more compatibility code

6 files changed, 3765 insertions, 523 deletions

diff --git a/filegraph.dot b/filegraph.dot
index 9eccd80..1228690 100644
--- a/filegraph.dot
+++ b/filegraph.dot
@@ -256,6 +256,7 @@ strict digraph luaotfload_files { //looks weird with circo ...
                 <tr> <td>luatex-font-tfm.lua</td>   <td>luatex-font-afm.lua</td>   </tr>
                 <tr> <td>luatex-font-afk.lua</td>   <td>luatex-fonts-tfm.lua</td>  </tr>
                 <tr> <td>luatex-fonts-chr.lua</td>  <td>luatex-fonts-lua.lua</td>  </tr>
+                <tr> <td>luatex-fonts-inj.lua</td>  <td>luatex-fonts-otn.lua</td>  </tr>
                 <tr> <td>luatex-fonts-def.lua</td>  <td>luatex-fonts-ext.lua</td>  </tr>
                 <tr> <td>luatex-fonts-cbk.lua</td>                                 </tr>
  
@@ -275,8 +276,8 @@ strict digraph luaotfload_files { //looks weird with circo ...
                 <th> <td colspan="3"> <font point-size="12" face="Iwona Italic"> Font and Node Libraries from Context </font> </td> </th>
                 <tr> <td>data-con.lua</td> <td>font-ini.lua</td> <td>font-con.lua</td> </tr>
                 <tr> <td>font-cid.lua</td> <td>font-map.lua</td> <td>font-oti.lua</td> </tr>
-                <tr> <td>font-otf.lua</td> <td>font-otb.lua</td> <td>node-inj.lua</td> </tr>
-                <tr> <td>font-ota.lua</td> <td>font-otn.lua</td> <td>font-def.lua</td> </tr>
+                <tr> <td>font-otf.lua</td> <td>font-otb.lua</td> <td>font-ota.lua</td> </tr>
+                <tr> <td>font-def.lua</td> </tr>
             </table>
         >,
     ]
diff --git a/luaotfload-auxiliary.lua b/luaotfload-auxiliary.lua
index 821a436..334ac47 100644
--- a/luaotfload-auxiliary.lua
+++ b/luaotfload-auxiliary.lua
@@ -15,28 +15,25 @@
 luaotfload                  = luaotfload or {}
 luaotfload.aux              = luaotfload.aux or { }
 
-config                      = config or { }
-config.luaotfload           = config.luaotfload or { }
-
-local aux           = luaotfload.aux
-local log           = luaotfload.log
-local warning       = luaotfload.log
-local fonthashes    = fonts.hashes
-local identifiers   = fonthashes.identifiers
-
-local fontid        = font.id
-local texsprint     = tex.sprint
-
-local dofile        = dofile
-local getmetatable  = getmetatable
-local setmetatable  = setmetatable
-local utf8          = unicode.utf8
-local stringlower   = string.lower
-local stringformat  = string.format
-local stringgsub    = string.gsub
-local stringbyte    = string.byte
-local stringfind    = string.find
-local tablecopy     = table.copy
+local aux                   = luaotfload.aux
+local log                   = luaotfload.log
+local warning               = luaotfload.log
+local fonthashes            = fonts.hashes
+local identifiers           = fonthashes.identifiers
+
+local fontid                = font.id
+local texsprint             = tex.sprint
+
+local dofile                = dofile
+local getmetatable          = getmetatable
+local setmetatable          = setmetatable
+local utf8                  = unicode.utf8
+local stringlower           = string.lower
+local stringformat          = string.format
+local stringgsub            = string.gsub
+local stringbyte            = string.byte
+local stringfind            = string.find
+local tablecopy             = table.copy
 
 -----------------------------------------------------------------------
 ---                          font patches
@@ -76,90 +73,6 @@ end
 
 aux.stop_rewrite_fontname = stop_rewrite_fontname
 
---- as of 2.3 the compatibility hacks for TL 2013 are made optional
-
-if config.luaotfload.compatibility == true then
-
---[[doc--
-
-The font object (tfmdata) structure has changed since version 1.x, so
-in case other packages haven’t been updated we put fallbacks in place
-where they’d expect them. Specifically we have in mind:
-
-  · fontspec
-  · unicode-math
-  · microtype (most likely fixed till TL2013)
-
---doc]]--
-
---- fontobj -> fontobj
-local add_fontdata_fallbacks = function (fontdata)
-  if type(fontdata) == "table" then
-    local fontparameters = fontdata.parameters
-    local metadata
-    if not fontdata.shared then --- that would be a tfm
-      --- we can’t really catch everything that
-      --- goes wrong; for some reason, fontspec.lua
-      --- just assumes it always gets an otf object,
-      --- so its capheight callback, which does not
-      --- bother to do any checks, will access
-      --- fontdata.shared no matter what ...
-      fontdata.units = fontdata.units_per_em
-
-    else --- otf
-      metadata         = fontdata.shared.rawdata.metadata
-      fontdata.name    = metadata.origname or fontdata.name
-      fontdata.units   = fontdata.units_per_em
-      fontdata.size    = fontdata.size or fontparameters.size
-      local resources  = fontdata.resources
-      --- for legacy fontspec.lua and unicode-math.lua
-      fontdata.shared.otfdata = {
-        pfminfo   = { os2_capheight = metadata.pfminfo.os2_capheight },
-        metadata  = { ascent = metadata.ascent },
-      }
-      --- for microtype and fontspec
-      --local fake_features = { }
-      local fake_features = table.copy(resources.features)
-      setmetatable(fake_features, { __index = function (tab, idx)
-          warning("some package (probably fontspec) is outdated")
-          warning(
-            "attempt to index " ..
-            "tfmdata.shared.otfdata.luatex.features (%s)",
-            idx)
-          --os.exit(1)
-          return tab[idx]
-        end,
-      })
-      fontdata.shared.otfdata.luatex = {
-        unicodes = resources.unicodes,
-        features = fake_features,
-      }
-    end
-  end
-  return fontdata
-end
-
-luatexbase.add_to_callback(
-  "luaotfload.patch_font",
-  add_fontdata_fallbacks,
-  "luaotfload.fontdata_fallbacks")
-
---[[doc--
-
-Additionally, the font registry is expected at fonts.identifiers
-(fontspec) or fonts.ids (microtype), but in the meantime it has been
-migrated to fonts.hashes.identifiers.  We’ll make luaotfload satisfy
-those assumptions. (Maybe it’d be more appropriate to use
-font.getfont() since Hans made it a harmless wrapper [1].)
-
-[1] http://www.ntg.nl/pipermail/ntg-context/2013/072166.html
-
---doc]]--
-
-fonts.identifiers = fonts.hashes.identifiers
-fonts.ids         = fonts.hashes.identifiers
-
-end
 
 --[[doc--
 This sets two dimensions apparently relied upon by the unicode-math
diff --git a/luaotfload-fontloader.lua b/luaotfload-fontloader.lua
index 2563739..a3a2de5 100644
--- a/luaotfload-fontloader.lua
+++ b/luaotfload-fontloader.lua
@@ -1,6 +1,6 @@
 -- merged file : luatex-fonts-merged.lua
 -- parent file : luatex-fonts.lua
--- merge date  : 01/06/14 18:10:50
+-- merge date  : 01/07/14 17:03:56
 
 do -- begin closure to overcome local limits and interference
 
@@ -6427,7 +6427,7 @@ local report_otf=logs.reporter("fonts","otf loading")
 local fonts=fonts
 local otf=fonts.handlers.otf
 otf.glists={ "gsub","gpos" }
-otf.version=2.749 
+otf.version=2.750 
 otf.cache=containers.define("fonts","otf",otf.version,true)
 local fontdata=fonts.hashes.identifiers
 local chardata=characters and characters.data 
@@ -8903,26 +8903,12 @@ nodes.injections=nodes.injections or {}
 local injections=nodes.injections
 local nodecodes=nodes.nodecodes
 local glyph_code=nodecodes.glyph
-local disc_code=nodecodes.disc
 local kern_code=nodecodes.kern
-local nuts=nodes.nuts
-local nodepool=nuts.pool
+local nodepool=nodes.pool
 local newkern=nodepool.kern
-local tonode=nuts.tonode
-local tonut=nuts.tonut
-local getfield=nuts.getfield
-local getnext=nuts.getnext
-local getprev=nuts.getprev
-local getid=nuts.getid
-local getattr=nuts.getattr
-local getfont=nuts.getfont
-local getsubtype=nuts.getsubtype
-local getchar=nuts.getchar
-local setfield=nuts.setfield
-local setattr=nuts.setattr
-local traverse_id=nuts.traverse_id
-local insert_node_before=nuts.insert_before
-local insert_node_after=nuts.insert_after
+local traverse_id=node.traverse_id
+local insert_node_before=node.insert_before
+local insert_node_after=node.insert_after
 local a_kernpair=attributes.private('kernpair')
 local a_ligacomp=attributes.private('ligacomp')
 local a_markbase=attributes.private('markbase')
@@ -8941,21 +8927,21 @@ function injections.setcursive(start,nxt,factor,rlmode,exit,entry,tfmstart,tfmne
   local dx,dy=factor*(exit[1]-entry[1]),factor*(exit[2]-entry[2])
   local ws,wn=tfmstart.width,tfmnext.width
   local bound=#cursives+1
-  setattr(start,a_cursbase,bound)
-  setattr(nxt,a_curscurs,bound)
+  start[a_cursbase]=bound
+  nxt[a_curscurs]=bound
   cursives[bound]={ rlmode,dx,dy,ws,wn }
   return dx,dy,bound
 end
 function injections.setpair(current,factor,rlmode,r2lflag,spec,tfmchr)
   local x,y,w,h=factor*spec[1],factor*spec[2],factor*spec[3],factor*spec[4]
   if x~=0 or w~=0 or y~=0 or h~=0 then
-    local bound=getattr(current,a_kernpair)
+    local bound=current[a_kernpair]
     if bound then
       local kb=kerns[bound]
       kb[2],kb[3],kb[4],kb[5]=(kb[2] or 0)+x,(kb[3] or 0)+y,(kb[4] or 0)+w,(kb[5] or 0)+h
     else
       bound=#kerns+1
-      setattr(current,a_kernpair,bound)
+      current[a_kernpair]=bound
       kerns[bound]={ rlmode,x,y,w,h,r2lflag,tfmchr.width }
     end
     return x,y,w,h,bound
@@ -8966,7 +8952,7 @@ function injections.setkern(current,factor,rlmode,x,tfmchr)
   local dx=factor*x
   if dx~=0 then
     local bound=#kerns+1
-    setattr(current,a_kernpair,bound)
+    current[a_kernpair]=bound
     kerns[bound]={ rlmode,dx }
     return dx,bound
   else
@@ -8975,25 +8961,25 @@ function injections.setkern(current,factor,rlmode,x,tfmchr)
 end
 function injections.setmark(start,base,factor,rlmode,ba,ma,index,baseismark) 
   local dx,dy=factor*(ba[1]-ma[1]),factor*(ba[2]-ma[2])   
-  local bound=getattr(base,a_markbase)          
+  local bound=base[a_markbase]          
   local index=1
   if bound then
     local mb=marks[bound]
     if mb then
       index=#mb+1
       mb[index]={ dx,dy,rlmode }
-      setattr(start,a_markmark,bound)
-      setattr(start,a_markdone,index)
+      start[a_markmark]=bound
+      start[a_markdone]=index
       return dx,dy,bound
     else
-      report_injections("possible problem, %U is base mark without data (id %a)",getchar(base),bound)
+      report_injections("possible problem, %U is base mark without data (id %a)",base.char,bound)
     end
   end
   index=index or 1
   bound=#marks+1
-  setattr(base,a_markbase,bound)
-  setattr(start,a_markmark,bound)
-  setattr(start,a_markdone,index)
+  base[a_markbase]=bound
+  start[a_markmark]=bound
+  start[a_markdone]=index
   marks[bound]={ [index]={ dx,dy,rlmode,baseismark } }
   return dx,dy,bound
 end
@@ -9003,15 +8989,15 @@ end
 local function trace(head)
   report_injections("begin run")
   for n in traverse_id(glyph_code,head) do
-    if getsubtype(n)<256 then
-      local kp=getattr(n,a_kernpair)
-      local mb=getattr(n,a_markbase)
-      local mm=getattr(n,a_markmark)
-      local md=getattr(n,a_markdone)
-      local cb=getattr(n,a_cursbase)
-      local cc=getattr(n,a_curscurs)
-      local char=getchar(n)
-      report_injections("font %s, char %U, glyph %c",getfont(n),char,char)
+    if n.subtype<256 then
+      local kp=n[a_kernpair]
+      local mb=n[a_markbase]
+      local mm=n[a_markmark]
+      local md=n[a_markdone]
+      local cb=n[a_cursbase]
+      local cc=n[a_curscurs]
+      local char=n.char
+      report_injections("font %s, char %U, glyph %c",n.font,char,char)
       if kp then
         local k=kerns[kp]
         if k[3] then
@@ -9052,23 +9038,21 @@ local function show_result(head)
   local current=head
   local skipping=false
   while current do
-    local id=getid(current)
+    local id=current.id
     if id==glyph_code then
-      report_injections("char: %C, width %p, xoffset %p, yoffset %p",
-        getchar(current),getfield(current,"width"),getfield(current,"xoffset"),getfield(current,"yoffset"))
+      report_injections("char: %C, width %p, xoffset %p, yoffset %p",current.char,current.width,current.xoffset,current.yoffset)
       skipping=false
     elseif id==kern_code then
-      report_injections("kern: %p",getfield(current,"kern"))
+      report_injections("kern: %p",current.kern)
       skipping=false
     elseif not skipping then
       report_injections()
       skipping=true
     end
-    current=getnext(current)
+    current=current.next
   end
 end
 function injections.handler(head,where,keep)
-  head=tonut(head)
   local has_marks,has_cursives,has_kerns=next(marks),next(cursives),next(kerns)
   if has_marks or has_cursives then
     if trace_injections then
@@ -9078,18 +9062,17 @@ function injections.handler(head,where,keep)
     if has_kerns then 
       local nf,tm=nil,nil
       for n in traverse_id(glyph_code,head) do 
-        if getsubtype(n)<256 then
+        if n.subtype<256 then
           nofvalid=nofvalid+1
           valid[nofvalid]=n
-          local f=getfont(n)
-          if f~=nf then
-            nf=f
-            tm=fontdata[nf].resources.marks 
+          if n.font~=nf then
+            nf=n.font
+            tm=fontdata[nf].resources.marks
           end
           if tm then
-            mk[n]=tm[getchar(n)]
+            mk[n]=tm[n.char]
           end
-          local k=getattr(n,a_kernpair)
+          local k=n[a_kernpair]
           if k then
             local kk=kerns[k]
             if kk then
@@ -9109,16 +9092,15 @@ function injections.handler(head,where,keep)
     else
       local nf,tm=nil,nil
       for n in traverse_id(glyph_code,head) do
-        if getsubtype(n)<256 then
+        if n.subtype<256 then
           nofvalid=nofvalid+1
           valid[nofvalid]=n
-          local f=getfont(n)
-          if f~=nf then
-            nf=f
-            tm=fontdata[nf].resources.marks 
+          if n.font~=nf then
+            nf=n.font
+            tm=fontdata[nf].resources.marks
           end
           if tm then
-            mk[n]=tm[getchar(n)]
+            mk[n]=tm[n.char]
           end
         end
       end
@@ -9127,7 +9109,7 @@ function injections.handler(head,where,keep)
       local cx={}
       if has_kerns and next(ky) then
         for n,k in next,ky do
-          setfield(n,"yoffset",k)
+          n.yoffset=k
         end
       end
       if has_cursives then
@@ -9136,9 +9118,9 @@ function injections.handler(head,where,keep)
         for i=1,nofvalid do 
           local n=valid[i]
           if not mk[n] then
-            local n_cursbase=getattr(n,a_cursbase)
+            local n_cursbase=n[a_cursbase]
             if p_cursbase then
-              local n_curscurs=getattr(n,a_curscurs)
+              local n_curscurs=n[a_curscurs]
               if p_cursbase==n_curscurs then
                 local c=cursives[n_curscurs]
                 if c then
@@ -9161,20 +9143,20 @@ function injections.handler(head,where,keep)
                 end
               end
             elseif maxt>0 then
-              local ny=getfield(n,"yoffset")
+              local ny=n.yoffset
               for i=maxt,1,-1 do
                 ny=ny+d[i]
                 local ti=t[i]
-                setfield(ti,"yoffset",getfield(ti,"yoffset")+ny)
+                ti.yoffset=ti.yoffset+ny
               end
               maxt=0
             end
             if not n_cursbase and maxt>0 then
-              local ny=getfield(n,"yoffset")
+              local ny=n.yoffset
               for i=maxt,1,-1 do
                 ny=ny+d[i]
                 local ti=t[i]
-                setfield(ti,"yoffset",ny)
+                ti.yoffset=ny
               end
               maxt=0
             end
@@ -9182,11 +9164,11 @@ function injections.handler(head,where,keep)
           end
         end
         if maxt>0 then
-          local ny=getfield(n,"yoffset")
+          local ny=n.yoffset
           for i=maxt,1,-1 do
             ny=ny+d[i]
             local ti=t[i]
-            setfield(ti,"yoffset",ny)
+            ti.yoffset=ny
           end
           maxt=0
         end
@@ -9197,66 +9179,57 @@ function injections.handler(head,where,keep)
       if has_marks then
         for i=1,nofvalid do
           local p=valid[i]
-          local p_markbase=getattr(p,a_markbase)
+          local p_markbase=p[a_markbase]
           if p_markbase then
             local mrks=marks[p_markbase]
             local nofmarks=#mrks
-            for n in traverse_id(glyph_code,getnext(p)) do
-              local n_markmark=getattr(n,a_markmark)
+            for n in traverse_id(glyph_code,p.next) do
+              local n_markmark=n[a_markmark]
               if p_markbase==n_markmark then
-                local index=getattr(n,a_markdone) or 1
+                local index=n[a_markdone] or 1
                 local d=mrks[index]
                 if d then
                   local rlmode=d[3]
                   local k=wx[p]
-                  local px=getfield(p,"xoffset")
-                  local ox=0
                   if k then
                     local x=k[2]
                     local w=k[4]
                     if w then
                       if rlmode and rlmode>=0 then
-                        ox=px-getfield(p,"width")+d[1]-(w-x)
+                        n.xoffset=p.xoffset-p.width+d[1]-(w-x)
                       else
-                        ox=px-d[1]-x
+                        n.xoffset=p.xoffset-d[1]-x
                       end
                     else
                       if rlmode and rlmode>=0 then
-                        ox=px-getfield(p,"width")+d[1]
+                        n.xoffset=p.xoffset-p.width+d[1]
                       else
-                        ox=px-d[1]-x
+                        n.xoffset=p.xoffset-d[1]-x
                       end
                     end
                   else
-                    local wp=getfield(p,"width")
-                    local wn=getfield(n,"width") 
                     if rlmode and rlmode>=0 then
-                      ox=px-wp+d[1]
+                      n.xoffset=p.xoffset-p.width+d[1]
                     else
-                      ox=px-d[1]
+                      n.xoffset=p.xoffset-d[1]
                     end
-                    if wn~=0 then
-                      insert_node_before(head,n,newkern(-wn/2))
-                      insert_node_after(head,n,newkern(-wn/2))
+                    local w=n.width
+                    if w~=0 then
+                      insert_node_before(head,n,newkern(-w/2))
+                      insert_node_after(head,n,newkern(-w/2))
                     end
                   end
-                  setfield(n,"xoffset",ox)
-                  local py=getfield(p,"yoffset")
-                  local oy=0
                   if mk[p] then
-                    oy=py+d[2]
+                    n.yoffset=p.yoffset+d[2]
                   else
-                    oy=getfield(n,"yoffset")+py+d[2]
+                    n.yoffset=n.yoffset+p.yoffset+d[2]
                   end
-                  setfield(n,"yoffset",oy)
                   if nofmarks==1 then
                     break
                   else
                     nofmarks=nofmarks-1
                   end
                 end
-              elseif not n_markmark then
-                break 
               else
               end
             end
@@ -9308,7 +9281,6 @@ function injections.handler(head,where,keep)
       if not keep then
         kerns={}
       end
-head=tonode(head)
       return head,true
     elseif not keep then
       kerns,cursives,marks={},{},{}
@@ -9318,14 +9290,14 @@ head=tonode(head)
       trace(head)
     end
     for n in traverse_id(glyph_code,head) do
-      if getsubtype(n)<256 then
-        local k=getattr(n,a_kernpair)
+      if n.subtype<256 then
+        local k=n[a_kernpair]
         if k then
           local kk=kerns[k]
           if kk then
             local rl,x,y,w=kk[1],kk[2] or 0,kk[3],kk[4]
             if y and y~=0 then
-              setfield(n,"yoffset",y) 
+              n.yoffset=y 
             end
             if w then
               local wx=w-x
@@ -9356,10 +9328,10 @@ head=tonode(head)
     if not keep then
       kerns={}
     end
-    return tonode(head),true
+    return head,true
   else
   end
-  return tonode(head),false
+  return head,false
 end
 
 end -- closure
@@ -9774,25 +9746,12 @@ registertracker("otf.positions","otf.marks,otf.kerns,otf.cursive")
 registertracker("otf.actions","otf.replacements,otf.positions")
 registertracker("otf.injections","nodes.injections")
 registertracker("*otf.sample","otf.steps,otf.actions,otf.analyzing")
-local nuts=nodes.nuts
-local tonode=nuts.tonode
-local tonut=nuts.tonut
-local getfield=nuts.getfield
-local getnext=nuts.getnext
-local getprev=nuts.getprev
-local getid=nuts.getid
-local getattr=nuts.getattr
-local getfont=nuts.getfont
-local getsubtype=nuts.getsubtype
-local getchar=nuts.getchar
-local setfield=nuts.setfield
-local setattr=nuts.setattr
-local insert_node_after=nuts.insert_after
-local delete_node=nuts.delete
-local copy_node=nuts.copy
-local find_node_tail=nuts.tail
-local flush_node_list=nuts.flush_list
-local end_of_math=nuts.end_of_math
+local insert_node_after=node.insert_after
+local delete_node=nodes.delete
+local copy_node=node.copy
+local find_node_tail=node.tail or node.slide
+local flush_node_list=node.flush_list
+local end_of_math=node.end_of_math
 local setmetatableindex=table.setmetatableindex
 local zwnj=0x200C
 local zwj=0x200D
@@ -9903,83 +9862,83 @@ local function pref(kind,lookupname)
   return formatters["feature %a, lookup %a"](kind,lookupname)
 end
 local function copy_glyph(g) 
-  local components=getfield(g,"components")
+  local components=g.components
   if components then
-    setfield(g,"components",nil)
+    g.components=nil
     local n=copy_node(g)
-    setfield(g,"components",components)
+    g.components=components
     return n
   else
     return copy_node(g)
   end
 end
 local function markstoligature(kind,lookupname,head,start,stop,char)
-  if start==stop and getchar(start)==char then
+  if start==stop and start.char==char then
     return head,start
   else
-    local prev=getprev(start)
-    local next=getnext(stop)
-    setfield(start,"prev",nil)
-    setfield(stop,"next",nil)
+    local prev=start.prev
+    local next=stop.next
+    start.prev=nil
+    stop.next=nil
     local base=copy_glyph(start)
     if head==start then
       head=base
     end
-    setfield(base,"char",char)
-    setfield(base,"subtype",ligature_code)
-    setfield(base,"components",start)
+    base.char=char
+    base.subtype=ligature_code
+    base.components=start
     if prev then
-      setfield(prev,"next",base)
+      prev.next=base
     end
     if next then
-      setfield(next,"prev",base)
+      next.prev=base
     end
-    setfield(base,"next",next)
-    setfield(base,"prev",prev)
+    base.next=next
+    base.prev=prev
     return head,base
   end
 end
 local function getcomponentindex(start)
-  if getid(start)~=glyph_code then
+  if start.id~=glyph_code then
     return 0
-  elseif getsubtype(start)==ligature_code then
+  elseif start.subtype==ligature_code then
     local i=0
-    local components=getfield(start,"components")
+    local components=start.components
     while components do
       i=i+getcomponentindex(components)
-      components=getnext(components)
+      components=components.next
     end
     return i
-  elseif not marks[getchar(start)] then
+  elseif not marks[start.char] then
     return 1
   else
     return 0
   end
 end
 local function toligature(kind,lookupname,head,start,stop,char,markflag,discfound) 
-  if start==stop and getchar(start)==char then
-    setfield(start,"char",char)
+  if start==stop and start.char==char then
+    start.char=char
     return head,start
   end
-  local prev=getprev(start)
-  local next=getnext(stop)
-  setfield(start,"prev",nil)
-  setfield(stop,"next",nil)
+  local prev=start.prev
+  local next=stop.next
+  start.prev=nil
+  stop.next=nil
   local base=copy_glyph(start)
   if start==head then
     head=base
   end
-  setfield(base,"char",char)
-  setfield(base,"subtype",ligature_code)
-  setfield(base,"components",start) 
+  base.char=char
+  base.subtype=ligature_code
+  base.components=start 
   if prev then
-    setfield(prev,"next",base)
+    prev.next=base
   end
   if next then
-    setfield(next,"prev",base)
+    next.prev=base
   end
-  setfield(base,"next",next)
-  setfield(base,"prev",prev)
+  base.next=next
+  base.prev=prev
   if not discfound then
     local deletemarks=markflag~="mark"
     local components=start
@@ -9988,42 +9947,42 @@ local function toligature(kind,lookupname,head,start,stop,char,markflag,discfoun
     local head=base
     local current=base
     while start do
-      local char=getchar(start)
+      local char=start.char
       if not marks[char] then
         baseindex=baseindex+componentindex
         componentindex=getcomponentindex(start)
       elseif not deletemarks then 
-        setattr(start,a_ligacomp,baseindex+(getattr(start,a_ligacomp) or componentindex))
+        start[a_ligacomp]=baseindex+(start[a_ligacomp] or componentindex)
         if trace_marks then
-          logwarning("%s: keep mark %s, gets index %s",pref(kind,lookupname),gref(char),getattr(start,a_ligacomp))
+          logwarning("%s: keep mark %s, gets index %s",pref(kind,lookupname),gref(char),start[a_ligacomp])
         end
         head,current=insert_node_after(head,current,copy_node(start)) 
       elseif trace_marks then
         logwarning("%s: delete mark %s",pref(kind,lookupname),gref(char))
       end
-      start=getnext(start)
+      start=start.next
     end
-    local start=getnext(current)
-    while start and getid(start)==glyph_code do
-      local char=getchar(start)
+    local start=current.next
+    while start and start.id==glyph_code do
+      local char=start.char
       if marks[char] then
-        setattr(start,a_ligacomp,baseindex+(getattr(start,a_ligacomp) or componentindex))
+        start[a_ligacomp]=baseindex+(start[a_ligacomp] or componentindex)
         if trace_marks then
-          logwarning("%s: set mark %s, gets index %s",pref(kind,lookupname),gref(char),getattr(start,a_ligacomp))
+          logwarning("%s: set mark %s, gets index %s",pref(kind,lookupname),gref(char),start[a_ligacomp])
         end
       else
         break
       end
-      start=getnext(start)
+      start=start.next
     end
   end
   return head,base
 end
 function handlers.gsub_single(head,start,kind,lookupname,replacement)
   if trace_singles then
-    logprocess("%s: replacing %s by single %s",pref(kind,lookupname),gref(getchar(start)),gref(replacement))
+    logprocess("%s: replacing %s by single %s",pref(kind,lookupname),gref(start.char),gref(replacement))
   end
-  setfield(start,"char",replacement)
+  start.char=replacement
   return head,start,true
 end
 local function get_alternative_glyph(start,alternatives,value,trace_alternatives)
@@ -10049,7 +10008,7 @@ local function get_alternative_glyph(start,alternatives,value,trace_alternatives
         return false,trace_alternatives and formatters["invalid value %a, %s"](value,"out of range")
       end
     elseif value==0 then
-      return getchar(start),trace_alternatives and formatters["invalid value %a, %s"](value,"no change")
+      return start.char,trace_alternatives and formatters["invalid value %a, %s"](value,"no change")
     elseif value<1 then
       return alternatives[1],trace_alternatives and formatters["invalid value %a, taking %a"](value,1)
     else
@@ -10060,25 +10019,25 @@ end
 local function multiple_glyphs(head,start,multiple,ignoremarks)
   local nofmultiples=#multiple
   if nofmultiples>0 then
-    setfield(start,"char",multiple[1])
+    start.char=multiple[1]
     if nofmultiples>1 then
-      local sn=getnext(start)
+      local sn=start.next
       for k=2,nofmultiples do
         local n=copy_node(start) 
-        setfield(n,"char",multiple[k])
-        setfield(n,"next",sn)
-        setfield(n,"prev",start)
+        n.char=multiple[k]
+        n.next=sn
+        n.prev=start
         if sn then
-          setfield(sn,"prev",n)
+          sn.prev=n
         end
-        setfield(start,"next",n)
+        start.next=n
         start=n
       end
     end
     return head,start,true
   else
     if trace_multiples then
-      logprocess("no multiple for %s",gref(getchar(start)))
+      logprocess("no multiple for %s",gref(start.char))
     end
     return head,start,false
   end
@@ -10088,34 +10047,34 @@ function handlers.gsub_alternate(head,start,kind,lookupname,alternative,sequence
   local choice,comment=get_alternative_glyph(start,alternative,value,trace_alternatives)
   if choice then
     if trace_alternatives then
-      logprocess("%s: replacing %s by alternative %a to %s, %s",pref(kind,lookupname),gref(getchar(start)),choice,gref(choice),comment)
+      logprocess("%s: replacing %s by alternative %a to %s, %s",pref(kind,lookupname),gref(start.char),choice,gref(choice),comment)
     end
-    setfield(start,"char",choice)
+    start.char=choice
   else
     if trace_alternatives then
-      logwarning("%s: no variant %a for %s, %s",pref(kind,lookupname),value,gref(getchar(start)),comment)
+      logwarning("%s: no variant %a for %s, %s",pref(kind,lookupname),value,gref(start.char),comment)
     end
   end
   return head,start,true
 end
 function handlers.gsub_multiple(head,start,kind,lookupname,multiple,sequence)
   if trace_multiples then
-    logprocess("%s: replacing %s by multiple %s",pref(kind,lookupname),gref(getchar(start)),gref(multiple))
+    logprocess("%s: replacing %s by multiple %s",pref(kind,lookupname),gref(start.char),gref(multiple))
   end
   return multiple_glyphs(head,start,multiple,sequence.flags[1])
 end
 function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
-  local s,stop,discfound=getnext(start),nil,false
-  local startchar=getchar(start)
+  local s,stop,discfound=start.next,nil,false
+  local startchar=start.char
   if marks[startchar] then
     while s do
-      local id=getid(s)
-      if id==glyph_code and getfont(s)==currentfont and getsubtype(s)<256 then
-        local lg=ligature[getchar(s)]
+      local id=s.id
+      if id==glyph_code and s.font==currentfont and s.subtype<256 then
+        local lg=ligature[s.char]
         if lg then
           stop=s
           ligature=lg
-          s=getnext(s)
+          s=s.next
         else
           break
         end
@@ -10127,9 +10086,9 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
       local lig=ligature.ligature
       if lig then
         if trace_ligatures then
-          local stopchar=getchar(stop)
+          local stopchar=stop.char
           head,start=markstoligature(kind,lookupname,head,start,stop,lig)
-          logprocess("%s: replacing %s upto %s by ligature %s case 1",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(getchar(start)))
+          logprocess("%s: replacing %s upto %s by ligature %s case 1",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(start.char))
         else
           head,start=markstoligature(kind,lookupname,head,start,stop,lig)
         end
@@ -10140,18 +10099,18 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
   else
     local skipmark=sequence.flags[1]
     while s do
-      local id=getid(s)
-      if id==glyph_code and getsubtype(s)<256 then
-        if getfont(s)==currentfont then
-          local char=getchar(s)
+      local id=s.id
+      if id==glyph_code and s.subtype<256 then
+        if s.font==currentfont then
+          local char=s.char
           if skipmark and marks[char] then
-            s=getnext(s)
+            s=s.next
           else
             local lg=ligature[char]
             if lg then
               stop=s
               ligature=lg
-              s=getnext(s)
+              s=s.next
             else
               break
             end
@@ -10161,7 +10120,7 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
         end
       elseif id==disc_code then
         discfound=true
-        s=getnext(s)
+        s=s.next
       else
         break
       end
@@ -10170,35 +10129,36 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
     if lig then
       if stop then
         if trace_ligatures then
-          local stopchar=getchar(stop)
+          local stopchar=stop.char
           head,start=toligature(kind,lookupname,head,start,stop,lig,skipmark,discfound)
-          logprocess("%s: replacing %s upto %s by ligature %s case 2",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(getchar(start)))
+          logprocess("%s: replacing %s upto %s by ligature %s case 2",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(start.char))
         else
           head,start=toligature(kind,lookupname,head,start,stop,lig,skipmark,discfound)
         end
+        return head,start,true
       else
-        setfield(start,"char",lig)
+        start.char=lig
         if trace_ligatures then
           logprocess("%s: replacing %s by (no real) ligature %s case 3",pref(kind,lookupname),gref(startchar),gref(lig))
         end
+        return head,start,true
       end
-      return head,start,true
     else
     end
   end
   return head,start,false
 end
 function handlers.gpos_mark2base(head,start,kind,lookupname,markanchors,sequence)
-  local markchar=getchar(start)
+  local markchar=start.char
   if marks[markchar] then
-    local base=getprev(start) 
-    if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-      local basechar=getchar(base)
+    local base=start.prev 
+    if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+      local basechar=base.char
       if marks[basechar] then
         while true do
-          base=getprev(base)
-          if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-            basechar=getchar(base)
+          base=base.prev
+          if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+            basechar=base.char
             if not marks[basechar] then
               break
             end
@@ -10247,16 +10207,16 @@ function handlers.gpos_mark2base(head,start,kind,lookupname,markanchors,sequence
   return head,start,false
 end
 function handlers.gpos_mark2ligature(head,start,kind,lookupname,markanchors,sequence)
-  local markchar=getchar(start)
+  local markchar=start.char
   if marks[markchar] then
-    local base=getprev(start) 
-    if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-      local basechar=getchar(base)
+    local base=start.prev 
+    if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+      local basechar=base.char
       if marks[basechar] then
         while true do
-          base=getprev(base)
-          if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-            basechar=getchar(base)
+          base=base.prev
+          if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+            basechar=base.char
             if not marks[basechar] then
               break
             end
@@ -10268,7 +10228,7 @@ function handlers.gpos_mark2ligature(head,start,kind,lookupname,markanchors,sequ
           end
         end
       end
-      local index=getattr(start,a_ligacomp)
+      local index=start[a_ligacomp]
       local baseanchors=descriptions[basechar]
       if baseanchors then
         baseanchors=baseanchors.anchors
@@ -10313,22 +10273,22 @@ function handlers.gpos_mark2ligature(head,start,kind,lookupname,markanchors,sequ
   return head,start,false
 end
 function handlers.gpos_mark2mark(head,start,kind,lookupname,markanchors,sequence)
-  local markchar=getchar(start)
+  local markchar=start.char
   if marks[markchar] then
-    local base=getprev(start) 
-    local slc=getattr(start,a_ligacomp)
+    local base=start.prev 
+    local slc=start[a_ligacomp]
     if slc then 
       while base do
-        local blc=getattr(base,a_ligacomp)
+        local blc=base[a_ligacomp]
         if blc and blc~=slc then
-          base=getprev(base)
+          base=base.prev
         else
           break
         end
       end
     end
-    if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then 
-      local basechar=getchar(base)
+    if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then 
+      local basechar=base.char
       local baseanchors=descriptions[basechar]
       if baseanchors then
         baseanchors=baseanchors.anchors
@@ -10366,20 +10326,20 @@ function handlers.gpos_mark2mark(head,start,kind,lookupname,markanchors,sequence
   return head,start,false
 end
 function handlers.gpos_cursive(head,start,kind,lookupname,exitanchors,sequence) 
-  local alreadydone=cursonce and getattr(start,a_cursbase)
+  local alreadydone=cursonce and start[a_cursbase]
   if not alreadydone then
     local done=false
-    local startchar=getchar(start)
+    local startchar=start.char
     if marks[startchar] then
       if trace_cursive then
         logprocess("%s: ignoring cursive for mark %s",pref(kind,lookupname),gref(startchar))
       end
     else
-      local nxt=getnext(start)
-      while not done and nxt and getid(nxt)==glyph_code and getfont(nxt)==currentfont and getsubtype(nxt)<256 do
-        local nextchar=getchar(nxt)
+      local nxt=start.next
+      while not done and nxt and nxt.id==glyph_code and nxt.font==currentfont and nxt.subtype<256 do
+        local nextchar=nxt.char
         if marks[nextchar] then
-          nxt=getnext(nxt)
+          nxt=nxt.next
         else
           local entryanchors=descriptions[nextchar]
           if entryanchors then
@@ -10413,13 +10373,13 @@ function handlers.gpos_cursive(head,start,kind,lookupname,exitanchors,sequence)
     return head,start,done
   else
     if trace_cursive and trace_details then
-      logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(getchar(start)),alreadydone)
+      logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(start.char),alreadydone)
     end
     return head,start,false
   end
 end
 function handlers.gpos_single(head,start,kind,lookupname,kerns,sequence)
-  local startchar=getchar(start)
+  local startchar=start.char
   local dx,dy,w,h=setpair(start,tfmdata.parameters.factor,rlmode,sequence.flags[4],kerns,characters[startchar])
   if trace_kerns then
     logprocess("%s: shifting single %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),dx,dy,w,h)
@@ -10427,33 +10387,33 @@ function handlers.gpos_single(head,start,kind,lookupname,kerns,sequence)
   return head,start,false
 end
 function handlers.gpos_pair(head,start,kind,lookupname,kerns,sequence)
-  local snext=getnext(start)
+  local snext=start.next
   if not snext then
     return head,start,false
   else
     local prev,done=start,false
     local factor=tfmdata.parameters.factor
     local lookuptype=lookuptypes[lookupname]
-    while snext and getid(snext)==glyph_code and getfont(snext)==currentfont and getsubtype(snext)<256 do
-      local nextchar=getchar(snext)
+    while snext and snext.id==glyph_code and snext.font==currentfont and snext.subtype<256 do
+      local nextchar=snext.char
       local krn=kerns[nextchar]
       if not krn and marks[nextchar] then
         prev=snext
-        snext=getnext(snext)
+        snext=snext.next
       else
         if not krn then
         elseif type(krn)=="table" then
           if lookuptype=="pair" then 
             local a,b=krn[2],krn[3]
             if a and #a>0 then
-              local startchar=getchar(start)
+              local startchar=start.char
               local x,y,w,h=setpair(start,factor,rlmode,sequence.flags[4],a,characters[startchar])
               if trace_kerns then
                 logprocess("%s: shifting first of pair %s and %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),gref(nextchar),x,y,w,h)
               end
             end
             if b and #b>0 then
-              local startchar=getchar(start)
+              local startchar=start.char
               local x,y,w,h=setpair(snext,factor,rlmode,sequence.flags[4],b,characters[nextchar])
               if trace_kerns then
                 logprocess("%s: shifting second of pair %s and %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),gref(nextchar),x,y,w,h)
@@ -10466,7 +10426,7 @@ function handlers.gpos_pair(head,start,kind,lookupname,kerns,sequence)
         elseif krn~=0 then
           local k=setkern(snext,factor,rlmode,krn)
           if trace_kerns then
-            logprocess("%s: inserting kern %s between %s and %s",pref(kind,lookupname),k,gref(getchar(prev)),gref(nextchar))
+            logprocess("%s: inserting kern %s between %s and %s",pref(kind,lookupname),k,gref(prev.char),gref(nextchar))
           end
           done=true
         end
@@ -10501,13 +10461,13 @@ function chainmores.chainsub(head,start,stop,kind,chainname,currentcontext,looku
   return head,start,false
 end
 function chainprocs.reversesub(head,start,stop,kind,chainname,currentcontext,lookuphash,replacements)
-  local char=getchar(start)
+  local char=start.char
   local replacement=replacements[char]
   if replacement then
     if trace_singles then
       logprocess("%s: single reverse replacement of %s by %s",cref(kind,chainname),gref(char),gref(replacement))
     end
-    setfield(start,"char",replacement)
+    start.char=replacement
     return head,start,true
   else
     return head,start,false
@@ -10520,8 +10480,8 @@ function chainprocs.gsub_single(head,start,stop,kind,chainname,currentcontext,lo
     logwarning("todo: check if we need to loop over the replacements: %s",concat(subtables," "))
   end
   while current do
-    if getid(current)==glyph_code then
-      local currentchar=getchar(current)
+    if current.id==glyph_code then
+      local currentchar=current.char
       local lookupname=subtables[1] 
       local replacement=lookuphash[lookupname]
       if not replacement then
@@ -10538,21 +10498,21 @@ function chainprocs.gsub_single(head,start,stop,kind,chainname,currentcontext,lo
           if trace_singles then
             logprocess("%s: replacing single %s by %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(currentchar),gref(replacement))
           end
-          setfield(current,"char",replacement)
+          current.char=replacement
         end
       end
       return head,start,true
     elseif current==stop then
       break
     else
-      current=getnext(current)
+      current=current.next
     end
   end
   return head,start,false
 end
 chainmores.gsub_single=chainprocs.gsub_single
 function chainprocs.gsub_multiple(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
-  local startchar=getchar(start)
+  local startchar=start.char
   local subtables=currentlookup.subtables
   local lookupname=subtables[1]
   local replacements=lookuphash[lookupname]
@@ -10581,8 +10541,8 @@ function chainprocs.gsub_alternate(head,start,stop,kind,chainname,currentcontext
   local subtables=currentlookup.subtables
   local value=featurevalue==true and tfmdata.shared.features[kind] or featurevalue
   while current do
-    if getid(current)==glyph_code then 
-      local currentchar=getchar(current)
+    if current.id==glyph_code then 
+      local currentchar=current.char
       local lookupname=subtables[1]
       local alternatives=lookuphash[lookupname]
       if not alternatives then
@@ -10597,7 +10557,7 @@ function chainprocs.gsub_alternate(head,start,stop,kind,chainname,currentcontext
             if trace_alternatives then
               logprocess("%s: replacing %s by alternative %a to %s, %s",cref(kind,chainname,chainlookupname,lookupname),gref(char),choice,gref(choice),comment)
             end
-            setfield(start,"char",choice)
+            start.char=choice
           else
             if trace_alternatives then
               logwarning("%s: no variant %a for %s, %s",cref(kind,chainname,chainlookupname,lookupname),value,gref(char),comment)
@@ -10611,14 +10571,14 @@ function chainprocs.gsub_alternate(head,start,stop,kind,chainname,currentcontext
     elseif current==stop then
       break
     else
-      current=getnext(current)
+      current=current.next
     end
   end
   return head,start,false
 end
 chainmores.gsub_alternate=chainprocs.gsub_alternate
 function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex)
-  local startchar=getchar(start)
+  local startchar=start.char
   local subtables=currentlookup.subtables
   local lookupname=subtables[1]
   local ligatures=lookuphash[lookupname]
@@ -10633,20 +10593,20 @@ function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,
         logwarning("%s: no ligatures starting with %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar))
       end
     else
-      local s=getnext(start)
+      local s=start.next
       local discfound=false
       local last=stop
       local nofreplacements=0
       local skipmark=currentlookup.flags[1]
       while s do
-        local id=getid(s)
+        local id=s.id
         if id==disc_code then
-          s=getnext(s)
+          s=s.next
           discfound=true
         else
-          local schar=getchar(s)
+          local schar=s.char
           if skipmark and marks[schar] then 
-            s=getnext(s)
+            s=s.next
           else
             local lg=ligatures[schar]
             if lg then
@@ -10654,7 +10614,7 @@ function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,
               if s==stop then
                 break
               else
-                s=getnext(s)
+                s=s.next
               end
             else
               break
@@ -10671,7 +10631,7 @@ function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,
           if start==stop then
             logprocess("%s: replacing character %s by ligature %s case 3",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(l2))
           else
-            logprocess("%s: replacing character %s upto %s by ligature %s case 4",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(getchar(stop)),gref(l2))
+            logprocess("%s: replacing character %s upto %s by ligature %s case 4",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(stop.char),gref(l2))
           end
         end
         head,start=toligature(kind,lookupname,head,start,stop,l2,currentlookup.flags[1],discfound)
@@ -10680,7 +10640,7 @@ function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,
         if start==stop then
           logwarning("%s: replacing character %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar))
         else
-          logwarning("%s: replacing character %s upto %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(getchar(stop)))
+          logwarning("%s: replacing character %s upto %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(stop.char))
         end
       end
     end
@@ -10689,7 +10649,7 @@ function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,
 end
 chainmores.gsub_ligature=chainprocs.gsub_ligature
 function chainprocs.gpos_mark2base(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
-  local markchar=getchar(start)
+  local markchar=start.char
   if marks[markchar] then
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
@@ -10698,14 +10658,14 @@ function chainprocs.gpos_mark2base(head,start,stop,kind,chainname,currentcontext
       markanchors=markanchors[markchar]
     end
     if markanchors then
-      local base=getprev(start) 
-      if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-        local basechar=getchar(base)
+      local base=start.prev 
+      if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+        local basechar=base.char
         if marks[basechar] then
           while true do
-            base=getprev(base)
-            if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-              basechar=getchar(base)
+            base=base.prev
+            if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+              basechar=base.char
               if not marks[basechar] then
                 break
               end
@@ -10752,7 +10712,7 @@ function chainprocs.gpos_mark2base(head,start,stop,kind,chainname,currentcontext
   return head,start,false
 end
 function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
-  local markchar=getchar(start)
+  local markchar=start.char
   if marks[markchar] then
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
@@ -10761,14 +10721,14 @@ function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcon
       markanchors=markanchors[markchar]
     end
     if markanchors then
-      local base=getprev(start) 
-      if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-        local basechar=getchar(base)
+      local base=start.prev 
+      if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+        local basechar=base.char
         if marks[basechar] then
           while true do
-            base=getprev(base)
-            if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
-              basechar=getchar(base)
+            base=base.prev
+            if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
+              basechar=base.char
               if not marks[basechar] then
                 break
               end
@@ -10780,7 +10740,7 @@ function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcon
             end
           end
         end
-        local index=getattr(start,a_ligacomp)
+        local index=start[a_ligacomp]
         local baseanchors=descriptions[basechar].anchors
         if baseanchors then
           local baseanchors=baseanchors['baselig']
@@ -10819,7 +10779,7 @@ function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcon
   return head,start,false
 end
 function chainprocs.gpos_mark2mark(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
-  local markchar=getchar(start)
+  local markchar=start.char
   if marks[markchar] then
       local subtables=currentlookup.subtables
       local lookupname=subtables[1]
@@ -10828,20 +10788,20 @@ function chainprocs.gpos_mark2mark(head,start,stop,kind,chainname,currentcontext
         markanchors=markanchors[markchar]
       end
       if markanchors then
-        local base=getprev(start) 
-        local slc=getattr(start,a_ligacomp)
+        local base=start.prev 
+        local slc=start[a_ligacomp]
         if slc then 
           while base do
-            local blc=getattr(base,a_ligacomp)
+            local blc=base[a_ligacomp]
             if blc and blc~=slc then
-              base=getprev(base)
+              base=base.prev
             else
               break
             end
           end
         end
-        if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then 
-          local basechar=getchar(base)
+        if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then 
+          local basechar=base.char
           local baseanchors=descriptions[basechar].anchors
           if baseanchors then
             baseanchors=baseanchors['basemark']
@@ -10877,9 +10837,9 @@ function chainprocs.gpos_mark2mark(head,start,stop,kind,chainname,currentcontext
   return head,start,false
 end
 function chainprocs.gpos_cursive(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
-  local alreadydone=cursonce and getattr(start,a_cursbase)
+  local alreadydone=cursonce and start[a_cursbase]
   if not alreadydone then
-    local startchar=getchar(start)
+    local startchar=start.char
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
     local exitanchors=lookuphash[lookupname]
@@ -10893,11 +10853,11 @@ function chainprocs.gpos_cursive(head,start,stop,kind,chainname,currentcontext,l
           logprocess("%s: ignoring cursive for mark %s",pref(kind,lookupname),gref(startchar))
         end
       else
-        local nxt=getnext(start)
-        while not done and nxt and getid(nxt)==glyph_code and getfont(nxt)==currentfont and getsubtype(nxt)<256 do
-          local nextchar=getchar(nxt)
+        local nxt=start.next
+        while not done and nxt and nxt.id==glyph_code and nxt.font==currentfont and nxt.subtype<256 do
+          local nextchar=nxt.char
           if marks[nextchar] then
-            nxt=getnext(nxt)
+            nxt=nxt.next
           else
             local entryanchors=descriptions[nextchar]
             if entryanchors then
@@ -10931,7 +10891,7 @@ function chainprocs.gpos_cursive(head,start,stop,kind,chainname,currentcontext,l
       return head,start,done
     else
       if trace_cursive and trace_details then
-        logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(getchar(start)),alreadydone)
+        logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(start.char),alreadydone)
       end
       return head,start,false
     end
@@ -10939,7 +10899,7 @@ function chainprocs.gpos_cursive(head,start,stop,kind,chainname,currentcontext,l
   return head,start,false
 end
 function chainprocs.gpos_single(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex,sequence)
-  local startchar=getchar(start)
+  local startchar=start.char
   local subtables=currentlookup.subtables
   local lookupname=subtables[1]
   local kerns=lookuphash[lookupname]
@@ -10956,9 +10916,9 @@ function chainprocs.gpos_single(head,start,stop,kind,chainname,currentcontext,lo
 end
 chainmores.gpos_single=chainprocs.gpos_single
 function chainprocs.gpos_pair(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex,sequence)
-  local snext=getnext(start)
+  local snext=start.next
   if snext then
-    local startchar=getchar(start)
+    local startchar=start.char
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
     local kerns=lookuphash[lookupname]
@@ -10968,26 +10928,26 @@ function chainprocs.gpos_pair(head,start,stop,kind,chainname,currentcontext,look
         local lookuptype=lookuptypes[lookupname]
         local prev,done=start,false
         local factor=tfmdata.parameters.factor
-        while snext and getid(snext)==glyph_code and getfont(snext)==currentfont and getsubtype(snext)<256 do
-          local nextchar=getchar(snext)
+        while snext and snext.id==glyph_code and snext.font==currentfont and snext.subtype<256 do
+          local nextchar=snext.char
           local krn=kerns[nextchar]
           if not krn and marks[nextchar] then
             prev=snext
-            snext=getnext(snext)
+            snext=snext.next
           else
             if not krn then
             elseif type(krn)=="table" then
               if lookuptype=="pair" then
                 local a,b=krn[2],krn[3]
                 if a and #a>0 then
-                  local startchar=getchar(start)
+                  local startchar=start.char
                   local x,y,w,h=setpair(start,factor,rlmode,sequence.flags[4],a,characters[startchar])
                   if trace_kerns then
                     logprocess("%s: shifting first of pair %s and %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),gref(nextchar),x,y,w,h)
                   end
                 end
                 if b and #b>0 then
-                  local startchar=getchar(start)
+                  local startchar=start.char
                   local x,y,w,h=setpair(snext,factor,rlmode,sequence.flags[4],b,characters[nextchar])
                   if trace_kerns then
                     logprocess("%s: shifting second of pair %s and %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),gref(nextchar),x,y,w,h)
@@ -10999,7 +10959,7 @@ function chainprocs.gpos_pair(head,start,stop,kind,chainname,currentcontext,look
                 if a and a~=0 then
                   local k=setkern(snext,factor,rlmode,a)
                   if trace_kerns then
-                    logprocess("%s: inserting first kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(getchar(prev)),gref(nextchar))
+                    logprocess("%s: inserting first kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(prev.char),gref(nextchar))
                   end
                 end
                 if b and b~=0 then
@@ -11010,7 +10970,7 @@ function chainprocs.gpos_pair(head,start,stop,kind,chainname,currentcontext,look
             elseif krn~=0 then
               local k=setkern(snext,factor,rlmode,krn)
               if trace_kerns then
-                logprocess("%s: inserting kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(getchar(prev)),gref(nextchar))
+                logprocess("%s: inserting kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(prev.char),gref(nextchar))
               end
               done=true
             end
@@ -11031,10 +10991,6 @@ local function show_skip(kind,chainname,char,ck,class)
     logwarning("%s: skipping char %s, class %a, rule %a, lookuptype %a",cref(kind,chainname),gref(char),class,ck[1],ck[2])
   end
 end
-local quit_on_no_replacement=true
-directives.register("otf.chain.quitonnoreplacement",function(value) 
-  quit_on_no_replacement=value
-end)
 local function normal_handle_contextchain(head,start,kind,chainname,contexts,sequence,lookuphash)
   local flags=sequence.flags
   local done=false
@@ -11052,7 +11008,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
     local seq=ck[3]
     local s=#seq
     if s==1 then
-      match=getid(current)==glyph_code and getfont(current)==currentfont and getsubtype(current)<256 and seq[1][getchar(current)]
+      match=current.id==glyph_code and current.font==currentfont and current.subtype<256 and seq[1][current.char]
     else
       local f,l=ck[4],ck[5]
       if f==1 and f==l then
@@ -11060,13 +11016,13 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
         if f==l then
         else
           local n=f+1
-          last=getnext(last)
+          last=last.next
           while n<=l do
             if last then
-              local id=getid(last)
+              local id=last.id
               if id==glyph_code then
-                if getfont(last)==currentfont and getsubtype(last)<256 then
-                  local char=getchar(last)
+                if last.font==currentfont and last.subtype<256 then
+                  local char=last.char
                   local ccd=descriptions[char]
                   if ccd then
                     local class=ccd.class
@@ -11075,10 +11031,10 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                       if trace_skips then
                         show_skip(kind,chainname,char,ck,class)
                       end
-                      last=getnext(last)
+                      last=last.next
                     elseif seq[n][char] then
                       if n<l then
-                        last=getnext(last)
+                        last=last.next
                       end
                       n=n+1
                     else
@@ -11094,7 +11050,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                   break
                 end
               elseif id==disc_code then
-                last=getnext(last)
+                last=last.next
               else
                 match=false
                 break
@@ -11107,15 +11063,15 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
         end
       end
       if match and f>1 then
-        local prev=getprev(start)
+        local prev=start.prev
         if prev then
           local n=f-1
           while n>=1 do
             if prev then
-              local id=getid(prev)
+              local id=prev.id
               if id==glyph_code then
-                if getfont(prev)==currentfont and getsubtype(prev)<256 then 
-                  local char=getchar(prev)
+                if prev.font==currentfont and prev.subtype<256 then 
+                  local char=prev.char
                   local ccd=descriptions[char]
                   if ccd then
                     local class=ccd.class
@@ -11145,7 +11101,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                 match=false
                 break
               end
-              prev=getprev(prev)
+              prev=prev.prev
             elseif seq[n][32] then 
               n=n -1
             else
@@ -11165,15 +11121,15 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
         end
       end
       if match and s>l then
-        local current=last and getnext(last)
+        local current=last and last.next
         if current then
           local n=l+1
           while n<=s do
             if current then
-              local id=getid(current)
+              local id=current.id
               if id==glyph_code then
-                if getfont(current)==currentfont and getsubtype(current)<256 then 
-                  local char=getchar(current)
+                if current.font==currentfont and current.subtype<256 then 
+                  local char=current.char
                   local ccd=descriptions[char]
                   if ccd then
                     local class=ccd.class
@@ -11203,7 +11159,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                 match=false
                 break
               end
-              current=getnext(current)
+              current=current.next
             elseif seq[n][32] then
               n=n+1
             else
@@ -11226,7 +11182,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
     if match then
       if trace_contexts then
         local rule,lookuptype,f,l=ck[1],ck[2],ck[4],ck[5]
-        local char=getchar(start)
+        local char=start.char
         if ck[9] then
           logwarning("%s: rule %s matches at char %s for (%s,%s,%s) chars, lookuptype %a, %a => %a",
             cref(kind,chainname),rule,gref(char),f-1,l-f+1,s-l,lookuptype,ck[9],ck[10])
@@ -11260,12 +11216,12 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
           repeat
             if skipped then
               while true do
-                local char=getchar(start)
+                local char=start.char
                 local ccd=descriptions[char]
                 if ccd then
                   local class=ccd.class
                   if class==skipmark or class==skipligature or class==skipbase or (markclass and class=="mark" and not markclass[char]) then
-                    start=getnext(start)
+                    start=start.next
                   else
                     break
                   end
@@ -11295,7 +11251,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
               end
             end
             if start then
-              start=getnext(start)
+              start=start.next
             else
             end
           until i>nofchainlookups
@@ -11305,7 +11261,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
         if replacements then
           head,start,done=chainprocs.reversesub(head,start,last,kind,chainname,ck,lookuphash,replacements) 
         else
-          done=quit_on_no_replacement 
+          done=true 
           if trace_contexts then
             logprocess("%s: skipping match",cref(kind,chainname))
           end
@@ -11422,7 +11378,6 @@ local function featuresprocessor(head,font,attr)
   if not lookuphash then
     return head,false
   end
-  head=tonut(head)
   if trace_steps then
     checkstep(head)
   end
@@ -11455,10 +11410,10 @@ local function featuresprocessor(head,font,attr)
       local handler=handlers[typ]
       local start=find_node_tail(head) 
       while start do
-        local id=getid(start)
+        local id=start.id
         if id==glyph_code then
-          if getfont(start)==font and getsubtype(start)<256 then
-            local a=getattr(start,0)
+          if start.font==font and start.subtype<256 then
+            local a=start[0]
             if a then
               a=a==attr
             else
@@ -11469,7 +11424,7 @@ local function featuresprocessor(head,font,attr)
                 local lookupname=subtables[i]
                 local lookupcache=lookuphash[lookupname]
                 if lookupcache then
-                  local lookupmatch=lookupcache[getchar(start)]
+                  local lookupmatch=lookupcache[start.char]
                   if lookupmatch then
                     head,start,success=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
                     if success then
@@ -11480,15 +11435,15 @@ local function featuresprocessor(head,font,attr)
                   report_missing_cache(typ,lookupname)
                 end
               end
-              if start then start=getprev(start) end
+              if start then start=start.prev end
             else
-              start=getprev(start)
+              start=start.prev
             end
           else
-            start=getprev(start)
+            start=start.prev
           end
         else
-          start=getprev(start)
+          start=start.prev
         end
       end
     else
@@ -11506,16 +11461,16 @@ local function featuresprocessor(head,font,attr)
             local head=start
             local done=false
             while start do
-              local id=getid(start)
-              if id==glyph_code and getfont(start)==font and getsubtype(start)<256 then
-                local a=getattr(start,0)
+              local id=start.id
+              if id==glyph_code and start.font==font and start.subtype<256 then
+                local a=start[0]
                 if a then
-                  a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
+                  a=(a==attr) and (not attribute or start[a_state]==attribute)
                 else
-                  a=not attribute or getattr(start,a_state)==attribute
+                  a=not attribute or start[a_state]==attribute
                 end
                 if a then
-                  local lookupmatch=lookupcache[getchar(start)]
+                  local lookupmatch=lookupcache[start.char]
                   if lookupmatch then
                     local ok
                     head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
@@ -11523,12 +11478,12 @@ local function featuresprocessor(head,font,attr)
                       done=true
                     end
                   end
-                  if start then start=getnext(start) end
+                  if start then start=start.next end
                 else
-                  start=getnext(start)
+                  start=start.next
                 end
               else
-                start=getnext(start)
+                start=start.next
               end
             end
             if done then
@@ -11537,18 +11492,18 @@ local function featuresprocessor(head,font,attr)
             end
           end
           local function kerndisc(disc) 
-            local prev=getprev(disc)
-            local next=getnext(disc)
+            local prev=disc.prev
+            local next=disc.next
             if prev and next then
-              setfield(prev,"next",next)
-              local a=getattr(prev,0)
+              prev.next=next
+              local a=prev[0]
               if a then
-                a=(a==attr) and (not attribute or getattr(prev,a_state)==attribute)
+                a=(a==attr) and (not attribute or prev[a_state]==attribute)
               else
-                a=not attribute or getattr(prev,a_state)==attribute
+                a=not attribute or prev[a_state]==attribute
               end
               if a then
-                local lookupmatch=lookupcache[getchar(prev)]
+                local lookupmatch=lookupcache[prev.char]
                 if lookupmatch then
                   local h,d,ok=handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
                   if ok then
@@ -11557,22 +11512,22 @@ local function featuresprocessor(head,font,attr)
                   end
                 end
               end
-              setfield(prev,"next",disc)
+              prev.next=disc
             end
             return next
           end
           while start do
-            local id=getid(start)
+            local id=start.id
             if id==glyph_code then
-              if getfont(start)==font and getsubtype(start)<256 then
-                local a=getattr(start,0)
+              if start.font==font and start.subtype<256 then
+                local a=start[0]
                 if a then
-                  a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
+                  a=(a==attr) and (not attribute or start[a_state]==attribute)
                 else
-                  a=not attribute or getattr(start,a_state)==attribute
+                  a=not attribute or start[a_state]==attribute
                 end
                 if a then
-                  local lookupmatch=lookupcache[getchar(start)]
+                  local lookupmatch=lookupcache[start.char]
                   if lookupmatch then
                     local ok
                     head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
@@ -11580,38 +11535,38 @@ local function featuresprocessor(head,font,attr)
                       success=true
                     end
                   end
-                  if start then start=getnext(start) end
+                  if start then start=start.next end
                 else
-                  start=getnext(start)
+                  start=start.next
                 end
               else
-                start=getnext(start)
+                start=start.next
               end
             elseif id==disc_code then
-              if getsubtype(start)==discretionary_code then
-                local pre=getfield(start,"pre")
+              if start.subtype==discretionary_code then
+                local pre=start.pre
                 if pre then
                   local new=subrun(pre)
-                  if new then setfield(start,"pre",new) end
+                  if new then start.pre=new end
                 end
-                local post=getfield(start,"post")
+                local post=start.post
                 if post then
                   local new=subrun(post)
-                  if new then setfield(start,"post",new) end
+                  if new then start.post=new end
                 end
-                local replace=getfield(start,"replace")
+                local replace=start.replace
                 if replace then
                   local new=subrun(replace)
-                  if new then setfield(start,"replace",new) end
+                  if new then start.replace=new end
                 end
 elseif typ=="gpos_single" or typ=="gpos_pair" then
   kerndisc(start)
               end
-              start=getnext(start)
+              start=start.next
             elseif id==whatsit_code then 
-              local subtype=getsubtype(start)
+              local subtype=start.subtype
               if subtype==dir_code then
-                local dir=getfield(start,"dir")
+                local dir=start.dir
                 if   dir=="+TRT" or dir=="+TLT" then
                   topstack=topstack+1
                   dirstack[topstack]=dir
@@ -11630,7 +11585,7 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                   report_process("directions after txtdir %a: parmode %a, txtmode %a, # stack %a, new dir %a",dir,rlparmode,rlmode,topstack,newdir)
                 end
               elseif subtype==localpar_code then
-                local dir=getfield(start,"dir")
+                local dir=start.dir
                 if dir=="TRT" then
                   rlparmode=-1
                 elseif dir=="TLT" then
@@ -11643,11 +11598,11 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                   report_process("directions after pardir %a: parmode %a, txtmode %a",dir,rlparmode,rlmode)
                 end
               end
-              start=getnext(start)
+              start=start.next
             elseif id==math_code then
-              start=getnext(end_of_math(start))
+              start=end_of_math(start).next
             else
-              start=getnext(start)
+              start=start.next
             end
           end
         end
@@ -11656,20 +11611,20 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
           local head=start
           local done=false
           while start do
-            local id=getid(start)
-            if id==glyph_code and getfont(start)==font and getsubtype(start)<256 then
-              local a=getattr(start,0)
+            local id=start.id
+            if id==glyph_code and start.id==font and start.subtype<256 then
+              local a=start[0]
               if a then
-                a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
+                a=(a==attr) and (not attribute or start[a_state]==attribute)
               else
-                a=not attribute or getattr(start,a_state)==attribute
+                a=not attribute or start[a_state]==attribute
               end
               if a then
                 for i=1,ns do
                   local lookupname=subtables[i]
                   local lookupcache=lookuphash[lookupname]
                   if lookupcache then
-                    local lookupmatch=lookupcache[getchar(start)]
+                    local lookupmatch=lookupcache[start.char]
                     if lookupmatch then
                       local ok
                       head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
@@ -11684,12 +11639,12 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                     report_missing_cache(typ,lookupname)
                   end
                 end
-                if start then start=getnext(start) end
+                if start then start=start.next end
               else
-                start=getnext(start)
+                start=start.next
               end
             else
-              start=getnext(start)
+              start=start.next
             end
           end
           if done then
@@ -11698,22 +11653,22 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
           end
         end
         local function kerndisc(disc) 
-          local prev=getprev(disc)
-          local next=getnext(disc)
+          local prev=disc.prev
+          local next=disc.next
           if prev and next then
-            setfield(prev,"next",next)
-            local a=getattr(prev,0)
+            prev.next=next
+            local a=prev[0]
             if a then
-              a=(a==attr) and (not attribute or getattr(prev,a_state)==attribute)
+              a=(a==attr) and (not attribute or prev[a_state]==attribute)
             else
-              a=not attribute or getattr(prev,a_state)==attribute
+              a=not attribute or prev[a_state]==attribute
             end
             if a then
               for i=1,ns do
                 local lookupname=subtables[i]
                 local lookupcache=lookuphash[lookupname]
                 if lookupcache then
-                  local lookupmatch=lookupcache[getchar(prev)]
+                  local lookupmatch=lookupcache[prev.char]
                   if lookupmatch then
                     local h,d,ok=handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
                     if ok then
@@ -11726,26 +11681,26 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                 end
               end
             end
-            setfield(prev,"next",disc)
+            prev.next=disc
           end
           return next
         end
         while start do
-          local id=getid(start)
+          local id=start.id
           if id==glyph_code then
-            if getfont(start)==font and getsubtype(start)<256 then
-              local a=getattr(start,0)
+            if start.font==font and start.subtype<256 then
+              local a=start[0]
               if a then
-                a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
+                a=(a==attr) and (not attribute or start[a_state]==attribute)
               else
-                a=not attribute or getattr(start,a_state)==attribute
+                a=not attribute or start[a_state]==attribute
               end
               if a then
                 for i=1,ns do
                   local lookupname=subtables[i]
                   local lookupcache=lookuphash[lookupname]
                   if lookupcache then
-                    local lookupmatch=lookupcache[getchar(start)]
+                    local lookupmatch=lookupcache[start.char]
                     if lookupmatch then
                       local ok
                       head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
@@ -11760,38 +11715,38 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                     report_missing_cache(typ,lookupname)
                   end
                 end
-                if start then start=getnext(start) end
+                if start then start=start.next end
               else
-                start=getnext(start)
+                start=start.next
               end
             else
-              start=getnext(start)
+              start=start.next
             end
           elseif id==disc_code then
-            if getsubtype(start)==discretionary_code then
-              local pre=getfield(start,"pre")
+            if start.subtype==discretionary_code then
+              local pre=start.pre
               if pre then
                 local new=subrun(pre)
-                if new then setfield(start,"pre",new) end
+                if new then start.pre=new end
               end
-              local post=getfield(start,"post")
+              local post=start.post
               if post then
                 local new=subrun(post)
-                if new then setfield(start,"post",new) end
+                if new then start.post=new end
               end
-              local replace=getfield(start,"replace")
+              local replace=start.replace
               if replace then
                 local new=subrun(replace)
-                if new then setfield(start,"replace",new) end
+                if new then start.replace=new end
               end
 elseif typ=="gpos_single" or typ=="gpos_pair" then
   kerndisc(start)
             end
-            start=getnext(start)
+            start=start.next
           elseif id==whatsit_code then
-            local subtype=getsubtype(start)
+            local subtype=start.subtype
             if subtype==dir_code then
-              local dir=getfield(start,"dir")
+              local dir=start.dir
               if   dir=="+TRT" or dir=="+TLT" then
                 topstack=topstack+1
                 dirstack[topstack]=dir
@@ -11810,7 +11765,7 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                 report_process("directions after txtdir %a: parmode %a, txtmode %a, # stack %a, new dir %a",dir,rlparmode,rlmode,topstack,newdir)
               end
             elseif subtype==localpar_code then
-              local dir=getfield(start,"dir")
+              local dir=start.dir
               if dir=="TRT" then
                 rlparmode=-1
               elseif dir=="TLT" then
@@ -11823,11 +11778,11 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                 report_process("directions after pardir %a: parmode %a, txtmode %a",dir,rlparmode,rlmode)
               end
             end
-            start=getnext(start)
+            start=start.next
           elseif id==math_code then
-            start=getnext(end_of_math(start))
+            start=end_of_math(start).next
           else
-            start=getnext(start)
+            start=start.next
           end
         end
       end
@@ -11839,7 +11794,6 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
       registerstep(head)
     end
   end
-  head=tonode(head)
   return head,done
 end
 local function generic(lookupdata,lookupname,unicode,lookuphash)
diff --git a/luaotfload-fonts-inj.lua b/luaotfload-fonts-inj.lua
new file mode 100644
index 0000000..ae48150
--- /dev/null
+++ b/luaotfload-fonts-inj.lua
@@ -0,0 +1,526 @@
+if not modules then modules = { } end modules ['node-inj'] = {
+    version   = 1.001,
+    comment   = "companion to node-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files",
+}
+
+-- This is very experimental (this will change when we have luatex > .50 and
+-- a few pending thingies are available. Also, Idris needs to make a few more
+-- test fonts. Btw, future versions of luatex will have extended glyph properties
+-- that can be of help. Some optimizations can go away when we have faster machines.
+
+-- todo: make a special one for context
+
+local next = next
+local utfchar = utf.char
+
+local trace_injections = false  trackers.register("nodes.injections", function(v) trace_injections = v end)
+
+local report_injections = logs.reporter("nodes","injections")
+
+local attributes, nodes, node = attributes, nodes, node
+
+fonts                    = fonts
+local fontdata           = fonts.hashes.identifiers
+
+nodes.injections         = nodes.injections or { }
+local injections         = nodes.injections
+
+local nodecodes          = nodes.nodecodes
+local glyph_code         = nodecodes.glyph
+local kern_code          = nodecodes.kern
+local nodepool           = nodes.pool
+local newkern            = nodepool.kern
+
+local traverse_id        = node.traverse_id
+local insert_node_before = node.insert_before
+local insert_node_after  = node.insert_after
+
+local a_kernpair = attributes.private('kernpair')
+local a_ligacomp = attributes.private('ligacomp')
+local a_markbase = attributes.private('markbase')
+local a_markmark = attributes.private('markmark')
+local a_markdone = attributes.private('markdone')
+local a_cursbase = attributes.private('cursbase')
+local a_curscurs = attributes.private('curscurs')
+local a_cursdone = attributes.private('cursdone')
+
+-- This injector has been tested by Idris Samawi Hamid (several arabic fonts as well as
+-- the rather demanding Husayni font), Khaled Hosny (latin and arabic) and Kaj Eigner
+-- (arabic, hebrew and thai) and myself (whatever font I come across). I'm pretty sure
+-- that this code is not 100% okay but examples are needed to figure things out.
+
+function injections.installnewkern(nk)
+    newkern = nk or newkern
+end
+
+local cursives = { }
+local marks    = { }
+local kerns    = { }
+
+-- Currently we do gpos/kern in a bit inofficial way but when we have the extra fields in
+-- glyphnodes to manipulate ht/dp/wd explicitly I will provide an alternative; also, we
+-- can share tables.
+
+-- For the moment we pass the r2l key ... volt/arabtype tests .. idris: this needs
+-- checking with husayni (volt and fontforge).
+
+function injections.setcursive(start,nxt,factor,rlmode,exit,entry,tfmstart,tfmnext)
+    local dx, dy = factor*(exit[1]-entry[1]), factor*(exit[2]-entry[2])
+    local ws, wn = tfmstart.width, tfmnext.width
+    local bound = #cursives + 1
+    start[a_cursbase] = bound
+    nxt[a_curscurs] = bound
+    cursives[bound] = { rlmode, dx, dy, ws, wn }
+    return dx, dy, bound
+end
+
+function injections.setpair(current,factor,rlmode,r2lflag,spec,tfmchr)
+    local x, y, w, h = factor*spec[1], factor*spec[2], factor*spec[3], factor*spec[4]
+    -- dy = y - h
+    if x ~= 0 or w ~= 0 or y ~= 0 or h ~= 0 then
+        local bound = current[a_kernpair]
+        if bound then
+            local kb = kerns[bound]
+            -- inefficient but singles have less, but weird anyway, needs checking
+            kb[2], kb[3], kb[4], kb[5] = (kb[2] or 0) + x, (kb[3] or 0) + y, (kb[4] or 0)+ w, (kb[5] or 0) + h
+        else
+            bound = #kerns + 1
+            current[a_kernpair] = bound
+            kerns[bound] = { rlmode, x, y, w, h, r2lflag, tfmchr.width }
+        end
+        return x, y, w, h, bound
+    end
+    return x, y, w, h -- no bound
+end
+
+function injections.setkern(current,factor,rlmode,x,tfmchr)
+    local dx = factor*x
+    if dx ~= 0 then
+        local bound = #kerns + 1
+        current[a_kernpair] = bound
+        kerns[bound] = { rlmode, dx }
+        return dx, bound
+    else
+        return 0, 0
+    end
+end
+
+function injections.setmark(start,base,factor,rlmode,ba,ma,index,baseismark) -- ba=baseanchor, ma=markanchor
+    local dx, dy = factor*(ba[1]-ma[1]), factor*(ba[2]-ma[2])     -- the index argument is no longer used but when this
+    local bound = base[a_markbase]                    -- fails again we should pass it
+    local index = 1
+    if bound then
+        local mb = marks[bound]
+        if mb then
+         -- if not index then index = #mb + 1 end
+            index = #mb + 1
+            mb[index] = { dx, dy, rlmode }
+            start[a_markmark] = bound
+            start[a_markdone] = index
+            return dx, dy, bound
+        else
+            report_injections("possible problem, %U is base mark without data (id %a)",base.char,bound)
+        end
+    end
+--     index = index or 1
+    index = index or 1
+    bound = #marks + 1
+    base[a_markbase] = bound
+    start[a_markmark] = bound
+    start[a_markdone] = index
+    marks[bound] = { [index] = { dx, dy, rlmode, baseismark } }
+    return dx, dy, bound
+end
+
+local function dir(n)
+    return (n and n<0 and "r-to-l") or (n and n>0 and "l-to-r") or "unset"
+end
+
+local function trace(head)
+    report_injections("begin run")
+    for n in traverse_id(glyph_code,head) do
+        if n.subtype < 256 then
+            local kp = n[a_kernpair]
+            local mb = n[a_markbase]
+            local mm = n[a_markmark]
+            local md = n[a_markdone]
+            local cb = n[a_cursbase]
+            local cc = n[a_curscurs]
+            local char = n.char
+            report_injections("font %s, char %U, glyph %c",n.font,char,char)
+            if kp then
+                local k = kerns[kp]
+                if k[3] then
+                    report_injections("  pairkern: dir %a, x %p, y %p, w %p, h %p",dir(k[1]),k[2],k[3],k[4],k[5])
+                else
+                    report_injections("  kern: dir %a, dx %p",dir(k[1]),k[2])
+                end
+            end
+            if mb then
+                report_injections("  markbase: bound %a",mb)
+            end
+            if mm then
+                local m = marks[mm]
+                if mb then
+                    local m = m[mb]
+                    if m then
+                        report_injections("  markmark: bound %a, index %a, dx %p, dy %p",mm,md,m[1],m[2])
+                    else
+                        report_injections("  markmark: bound %a, missing index",mm)
+                    end
+                else
+                    m = m[1]
+                    report_injections("  markmark: bound %a, dx %p, dy %p",mm,m and m[1],m and m[2])
+                end
+            end
+            if cb then
+                report_injections("  cursbase: bound %a",cb)
+            end
+            if cc then
+                local c = cursives[cc]
+                report_injections("  curscurs: bound %a, dir %a, dx %p, dy %p",cc,dir(c[1]),c[2],c[3])
+            end
+        end
+    end
+    report_injections("end run")
+end
+
+-- todo: reuse tables (i.e. no collection), but will be extra fields anyway
+-- todo: check for attribute
+
+-- We can have a fast test on a font being processed, so we can check faster for marks etc
+-- but I'll make a context variant anyway.
+
+local function show_result(head)
+    local current = head
+    local skipping = false
+    while current do
+        local id = current.id
+        if id == glyph_code then
+            report_injections("char: %C, width %p, xoffset %p, yoffset %p",current.char,current.width,current.xoffset,current.yoffset)
+            skipping = false
+        elseif id == kern_code then
+            report_injections("kern: %p",current.kern)
+            skipping = false
+        elseif not skipping then
+            report_injections()
+            skipping = true
+        end
+        current = current.next
+    end
+end
+
+function injections.handler(head,where,keep)
+    local has_marks, has_cursives, has_kerns = next(marks), next(cursives), next(kerns)
+    if has_marks or has_cursives then
+        if trace_injections then
+            trace(head)
+        end
+        -- in the future variant we will not copy items but refs to tables
+        local done, ky, rl, valid, cx, wx, mk, nofvalid = false, { }, { }, { }, { }, { }, { }, 0
+        if has_kerns then -- move outside loop
+            local nf, tm = nil, nil
+            for n in traverse_id(glyph_code,head) do -- only needed for relevant fonts
+                if n.subtype < 256 then
+                    nofvalid = nofvalid + 1
+                    valid[nofvalid] = n
+                    if n.font ~= nf then
+                        nf = n.font
+                        tm = fontdata[nf].resources.marks
+                    end
+                    if tm then
+                        mk[n] = tm[n.char]
+                    end
+                    local k = n[a_kernpair]
+                    if k then
+                        local kk = kerns[k]
+                        if kk then
+                            local x, y, w, h = kk[2] or 0, kk[3] or 0, kk[4] or 0, kk[5] or 0
+                            local dy = y - h
+                            if dy ~= 0 then
+                                ky[n] = dy
+                            end
+                            if w ~= 0 or x ~= 0 then
+                                wx[n] = kk
+                            end
+                            rl[n] = kk[1] -- could move in test
+                        end
+                    end
+                end
+            end
+        else
+            local nf, tm = nil, nil
+            for n in traverse_id(glyph_code,head) do
+                if n.subtype < 256 then
+                    nofvalid = nofvalid + 1
+                    valid[nofvalid] = n
+                    if n.font ~= nf then
+                        nf = n.font
+                        tm = fontdata[nf].resources.marks
+                    end
+                    if tm then
+                        mk[n] = tm[n.char]
+                    end
+                end
+            end
+        end
+        if nofvalid > 0 then
+            -- we can assume done == true because we have cursives and marks
+            local cx = { }
+            if has_kerns and next(ky) then
+                for n, k in next, ky do
+                    n.yoffset = k
+                end
+            end
+            -- todo: reuse t and use maxt
+            if has_cursives then
+                local p_cursbase, p = nil, nil
+                -- since we need valid[n+1] we can also use a "while true do"
+                local t, d, maxt = { }, { }, 0
+                for i=1,nofvalid do -- valid == glyphs
+                    local n = valid[i]
+                    if not mk[n] then
+                        local n_cursbase = n[a_cursbase]
+                        if p_cursbase then
+                            local n_curscurs = n[a_curscurs]
+                            if p_cursbase == n_curscurs then
+                                local c = cursives[n_curscurs]
+                                if c then
+                                    local rlmode, dx, dy, ws, wn = c[1], c[2], c[3], c[4], c[5]
+                                    if rlmode >= 0 then
+                                        dx = dx - ws
+                                    else
+                                        dx = dx + wn
+                                    end
+                                    if dx ~= 0 then
+                                        cx[n] = dx
+                                        rl[n] = rlmode
+                                    end
+                                --  if rlmode and rlmode < 0 then
+                                        dy = -dy
+                                --  end
+                                    maxt = maxt + 1
+                                    t[maxt] = p
+                                    d[maxt] = dy
+                                else
+                                    maxt = 0
+                                end
+                            end
+                        elseif maxt > 0 then
+                            local ny = n.yoffset
+                            for i=maxt,1,-1 do
+                                ny = ny + d[i]
+                                local ti = t[i]
+                                ti.yoffset = ti.yoffset + ny
+                            end
+                            maxt = 0
+                        end
+                        if not n_cursbase and maxt > 0 then
+                            local ny = n.yoffset
+                            for i=maxt,1,-1 do
+                                ny = ny + d[i]
+                                local ti = t[i]
+                                ti.yoffset = ny
+                            end
+                            maxt = 0
+                        end
+                        p_cursbase, p = n_cursbase, n
+                    end
+                end
+                if maxt > 0 then
+                    local ny = n.yoffset
+                    for i=maxt,1,-1 do
+                        ny = ny + d[i]
+                        local ti = t[i]
+                        ti.yoffset = ny
+                    end
+                    maxt = 0
+                end
+                if not keep then
+                    cursives = { }
+                end
+            end
+            if has_marks then
+                for i=1,nofvalid do
+                    local p = valid[i]
+                    local p_markbase = p[a_markbase]
+                    if p_markbase then
+                        local mrks = marks[p_markbase]
+                        local nofmarks = #mrks
+                        for n in traverse_id(glyph_code,p.next) do
+                            local n_markmark = n[a_markmark]
+                            if p_markbase == n_markmark then
+                                local index = n[a_markdone] or 1
+                                local d = mrks[index]
+                                if d then
+                                    local rlmode = d[3]
+                                    --
+                                    local k = wx[p]
+                                    if k then
+                                        local x = k[2]
+                                        local w = k[4]
+                                        if w then
+                                            if rlmode and rlmode >= 0 then
+                                                -- kern(x) glyph(p) kern(w-x) mark(n)
+                                                n.xoffset = p.xoffset - p.width + d[1] - (w-x)
+                                            else
+                                                -- kern(w-x) glyph(p) kern(x) mark(n)
+                                                n.xoffset = p.xoffset - d[1] - x
+                                            end
+                                        else
+                                            if rlmode and rlmode >= 0 then
+                                                -- okay for husayni
+                                                n.xoffset = p.xoffset - p.width + d[1]
+                                            else
+                                                -- needs checking: is x ok here?
+                                                n.xoffset = p.xoffset - d[1] - x
+                                            end
+                                        end
+                                    else
+                                        if rlmode and rlmode >= 0 then
+                                            n.xoffset = p.xoffset - p.width + d[1]
+                                        else
+                                            n.xoffset = p.xoffset - d[1]
+                                        end
+                                        local w = n.width
+                                        if w ~= 0 then
+                                            insert_node_before(head,n,newkern(-w/2))
+                                            insert_node_after(head,n,newkern(-w/2))
+                                        end
+                                    end
+                                    --                                    --
+                                    if mk[p] then
+                                        n.yoffset = p.yoffset + d[2]
+                                    else
+                                        n.yoffset = n.yoffset + p.yoffset + d[2]
+                                    end
+                                    --
+                                    if nofmarks == 1 then
+                                        break
+                                    else
+                                        nofmarks = nofmarks - 1
+                                    end
+                                end
+                            else
+                                -- KE: there can be <mark> <mkmk> <mark> sequences in ligatures
+                            end
+                        end
+                    end
+                end
+                if not keep then
+                    marks = { }
+                end
+            end
+            -- todo : combine
+            if next(wx) then
+                for n, k in next, wx do
+                 -- only w can be nil (kernclasses), can be sped up when w == nil
+                    local x = k[2]
+                    local w = k[4]
+                    if w then
+                        local rl = k[1] -- r2l = k[6]
+                        local wx = w - x
+                        if rl < 0 then	-- KE: don't use r2l here
+                            if wx ~= 0 then
+                                insert_node_before(head,n,newkern(wx)) -- type 0/2
+                            end
+                            if x ~= 0 then
+                                insert_node_after (head,n,newkern(x))  -- type 0/2
+                            end
+                        else
+                            if x ~= 0 then
+                                insert_node_before(head,n,newkern(x))  -- type 0/2
+                            end
+                            if wx ~= 0 then
+                                insert_node_after (head,n,newkern(wx)) -- type 0/2
+                            end
+                        end
+                    elseif x ~= 0 then
+                        -- this needs checking for rl < 0 but it is unlikely that a r2l script
+                        -- uses kernclasses between glyphs so we're probably safe (KE has a
+                        -- problematic font where marks interfere with rl < 0 in the previous
+                        -- case)
+                        insert_node_before(head,n,newkern(x)) -- a real font kern, type 0
+                    end
+                end
+            end
+            if next(cx) then
+                for n, k in next, cx do
+                    if k ~= 0 then
+                        local rln = rl[n]
+                        if rln and rln < 0 then
+                            insert_node_before(head,n,newkern(-k)) -- type 0/2
+                        else
+                            insert_node_before(head,n,newkern(k))  -- type 0/2
+                        end
+                    end
+                end
+            end
+            if not keep then
+                kerns = { }
+            end
+         -- if trace_injections then
+         --     show_result(head)
+         -- end
+            return head, true
+        elseif not keep then
+            kerns, cursives, marks = { }, { }, { }
+        end
+    elseif has_kerns then
+        if trace_injections then
+            trace(head)
+        end
+        for n in traverse_id(glyph_code,head) do
+            if n.subtype < 256 then
+                local k = n[a_kernpair]
+                if k then
+                    local kk = kerns[k]
+                    if kk then
+                        local rl, x, y, w = kk[1], kk[2] or 0, kk[3], kk[4]
+                        if y and y ~= 0 then
+                            n.yoffset = y -- todo: h ?
+                        end
+                        if w then
+                            -- copied from above
+                         -- local r2l = kk[6]
+                            local wx = w - x
+                            if rl < 0 then  -- KE: don't use r2l here
+                                if wx ~= 0 then
+                                    insert_node_before(head,n,newkern(wx))
+                                end
+                                if x ~= 0 then
+                                    insert_node_after (head,n,newkern(x))
+                                end
+                            else
+                                if x ~= 0 then
+                                    insert_node_before(head,n,newkern(x))
+                                end
+                                if wx ~= 0 then
+                                    insert_node_after(head,n,newkern(wx))
+                                end
+                            end
+                        else
+                            -- simple (e.g. kernclass kerns)
+                            if x ~= 0 then
+                                insert_node_before(head,n,newkern(x))
+                            end
+                        end
+                    end
+                end
+            end
+        end
+        if not keep then
+            kerns = { }
+        end
+     -- if trace_injections then
+     --     show_result(head)
+     -- end
+        return head, true
+    else
+        -- no tracing needed
+    end
+    return head, false
+end
diff --git a/luaotfload-fonts-otn.lua b/luaotfload-fonts-otn.lua
new file mode 100644
index 0000000..c57be5f
--- /dev/null
+++ b/luaotfload-fonts-otn.lua
@@ -0,0 +1,2848 @@
+if not modules then modules = { } end modules ['font-otn'] = {
+    version   = 1.001,
+    comment   = "companion to font-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files",
+}
+
+-- preprocessors = { "nodes" }
+
+-- this is still somewhat preliminary and it will get better in due time;
+-- much functionality could only be implemented thanks to the husayni font
+-- of Idris Samawi Hamid to who we dedicate this module.
+
+-- in retrospect it always looks easy but believe it or not, it took a lot
+-- of work to get proper open type support done: buggy fonts, fuzzy specs,
+-- special made testfonts, many skype sessions between taco, idris and me,
+-- torture tests etc etc ... unfortunately the code does not show how much
+-- time it took ...
+
+-- todo:
+--
+-- kerning is probably not yet ok for latin around dics nodes (interesting challenge)
+-- extension infrastructure (for usage out of context)
+-- sorting features according to vendors/renderers
+-- alternative loop quitters
+-- check cursive and r2l
+-- find out where ignore-mark-classes went
+-- default features (per language, script)
+-- handle positions (we need example fonts)
+-- handle gpos_single (we might want an extra width field in glyph nodes because adding kerns might interfere)
+-- mark (to mark) code is still not what it should be (too messy but we need some more extreem husayni tests)
+-- remove some optimizations (when I have a faster machine)
+--
+-- maybe redo the lot some way (more context specific)
+
+--[[ldx--
+<p>This module is a bit more split up that I'd like but since we also want to test
+with plain <l n='tex'/> it has to be so. This module is part of <l n='context'/>
+and discussion about improvements and functionality mostly happens on the
+<l n='context'/> mailing list.</p>
+
+<p>The specification of OpenType is kind of vague. Apart from a lack of a proper
+free specifications there's also the problem that Microsoft and Adobe
+may have their own interpretation of how and in what order to apply features.
+In general the Microsoft website has more detailed specifications and is a
+better reference. There is also some information in the FontForge help files.</p>
+
+<p>Because there is so much possible, fonts might contain bugs and/or be made to
+work with certain rederers. These may evolve over time which may have the side
+effect that suddenly fonts behave differently.</p>
+
+<p>After a lot of experiments (mostly by Taco, me and Idris) we're now at yet another
+implementation. Of course all errors are mine and of course the code can be
+improved. There are quite some optimizations going on here and processing speed
+is currently acceptable. Not all functions are implemented yet, often because I
+lack the fonts for testing. Many scripts are not yet supported either, but I will
+look into them as soon as <l n='context'/> users ask for it.</p>
+
+<p>Because there are different interpretations possible, I will extend the code
+with more (configureable) variants. I can also add hooks for users so that they can
+write their own extensions.</p>
+
+<p>Glyphs are indexed not by unicode but in their own way. This is because there is no
+relationship with unicode at all, apart from the fact that a font might cover certain
+ranges of characters. One character can have multiple shapes. However, at the
+<l n='tex'/> end we use unicode so and all extra glyphs are mapped into a private
+space. This is needed because we need to access them and <l n='tex'/> has to include
+then in the output eventually.</p>
+
+<p>The raw table as it coms from <l n='fontforge'/> gets reorganized in to fit out needs.
+In <l n='context'/> that table is packed (similar tables are shared) and cached on disk
+so that successive runs can use the optimized table (after loading the table is
+unpacked). The flattening code used later is a prelude to an even more compact table
+format (and as such it keeps evolving).</p>
+
+<p>This module is sparsely documented because it is a moving target. The table format
+of the reader changes and we experiment a lot with different methods for supporting
+features.</p>
+
+<p>As with the <l n='afm'/> code, we may decide to store more information in the
+<l n='otf'/> table.</p>
+
+<p>Incrementing the version number will force a re-cache. We jump the number by one
+when there's a fix in the <l n='fontforge'/> library or <l n='lua'/> code that
+results in different tables.</p>
+--ldx]]--
+
+-- action                    handler     chainproc             chainmore              comment
+--
+-- gsub_single               ok          ok                    ok
+-- gsub_multiple             ok          ok                    not implemented yet
+-- gsub_alternate            ok          ok                    not implemented yet
+-- gsub_ligature             ok          ok                    ok
+-- gsub_context              ok          --
+-- gsub_contextchain         ok          --
+-- gsub_reversecontextchain  ok          --
+-- chainsub                  --          ok
+-- reversesub                --          ok
+-- gpos_mark2base            ok          ok
+-- gpos_mark2ligature        ok          ok
+-- gpos_mark2mark            ok          ok
+-- gpos_cursive              ok          untested
+-- gpos_single               ok          ok
+-- gpos_pair                 ok          ok
+-- gpos_context              ok          --
+-- gpos_contextchain         ok          --
+--
+-- todo: contextpos and contextsub and class stuff
+--
+-- actions:
+--
+-- handler   : actions triggered by lookup
+-- chainproc : actions triggered by contextual lookup
+-- chainmore : multiple substitutions triggered by contextual lookup (e.g. fij -> f + ij)
+--
+-- remark: the 'not implemented yet' variants will be done when we have fonts that use them
+-- remark: we need to check what to do with discretionaries
+
+-- We used to have independent hashes for lookups but as the tags are unique
+-- we now use only one hash. If needed we can have multiple again but in that
+-- case I will probably prefix (i.e. rename) the lookups in the cached font file.
+
+-- Todo: make plugin feature that operates on char/glyphnode arrays
+
+local concat, insert, remove = table.concat, table.insert, table.remove
+local gmatch, gsub, find, match, lower, strip = string.gmatch, string.gsub, string.find, string.match, string.lower, string.strip
+local type, next, tonumber, tostring = type, next, tonumber, tostring
+local lpegmatch = lpeg.match
+local random = math.random
+local formatters = string.formatters
+
+local logs, trackers, nodes, attributes = logs, trackers, nodes, attributes
+
+local registertracker = trackers.register
+
+local fonts = fonts
+local otf   = fonts.handlers.otf
+
+local trace_lookups      = false  registertracker("otf.lookups",      function(v) trace_lookups      = v end)
+local trace_singles      = false  registertracker("otf.singles",      function(v) trace_singles      = v end)
+local trace_multiples    = false  registertracker("otf.multiples",    function(v) trace_multiples    = v end)
+local trace_alternatives = false  registertracker("otf.alternatives", function(v) trace_alternatives = v end)
+local trace_ligatures    = false  registertracker("otf.ligatures",    function(v) trace_ligatures    = v end)
+local trace_contexts     = false  registertracker("otf.contexts",     function(v) trace_contexts     = v end)
+local trace_marks        = false  registertracker("otf.marks",        function(v) trace_marks        = v end)
+local trace_kerns        = false  registertracker("otf.kerns",        function(v) trace_kerns        = v end)
+local trace_cursive      = false  registertracker("otf.cursive",      function(v) trace_cursive      = v end)
+local trace_preparing    = false  registertracker("otf.preparing",    function(v) trace_preparing    = v end)
+local trace_bugs         = false  registertracker("otf.bugs",         function(v) trace_bugs         = v end)
+local trace_details      = false  registertracker("otf.details",      function(v) trace_details      = v end)
+local trace_applied      = false  registertracker("otf.applied",      function(v) trace_applied      = v end)
+local trace_steps        = false  registertracker("otf.steps",        function(v) trace_steps        = v end)
+local trace_skips        = false  registertracker("otf.skips",        function(v) trace_skips        = v end)
+local trace_directions   = false  registertracker("otf.directions",   function(v) trace_directions   = v end)
+
+local report_direct   = logs.reporter("fonts","otf direct")
+local report_subchain = logs.reporter("fonts","otf subchain")
+local report_chain    = logs.reporter("fonts","otf chain")
+local report_process  = logs.reporter("fonts","otf process")
+local report_prepare  = logs.reporter("fonts","otf prepare")
+local report_warning  = logs.reporter("fonts","otf warning")
+
+registertracker("otf.verbose_chain", function(v) otf.setcontextchain(v and "verbose") end)
+registertracker("otf.normal_chain",  function(v) otf.setcontextchain(v and "normal")  end)
+
+registertracker("otf.replacements", "otf.singles,otf.multiples,otf.alternatives,otf.ligatures")
+registertracker("otf.positions","otf.marks,otf.kerns,otf.cursive")
+registertracker("otf.actions","otf.replacements,otf.positions")
+registertracker("otf.injections","nodes.injections")
+
+registertracker("*otf.sample","otf.steps,otf.actions,otf.analyzing")
+
+local insert_node_after  = node.insert_after
+local delete_node        = nodes.delete
+local copy_node          = node.copy
+local find_node_tail     = node.tail or node.slide
+local flush_node_list    = node.flush_list
+local end_of_math        = node.end_of_math
+
+local setmetatableindex  = table.setmetatableindex
+
+local zwnj               = 0x200C
+local zwj                = 0x200D
+local wildcard           = "*"
+local default            = "dflt"
+
+local nodecodes          = nodes.nodecodes
+local whatcodes          = nodes.whatcodes
+local glyphcodes         = nodes.glyphcodes
+local disccodes          = nodes.disccodes
+
+local glyph_code         = nodecodes.glyph
+local glue_code          = nodecodes.glue
+local disc_code          = nodecodes.disc
+local whatsit_code       = nodecodes.whatsit
+local math_code          = nodecodes.math
+
+local dir_code           = whatcodes.dir
+local localpar_code      = whatcodes.localpar
+
+local discretionary_code = disccodes.discretionary
+
+local ligature_code      = glyphcodes.ligature
+
+local privateattribute   = attributes.private
+
+-- Something is messed up: we have two mark / ligature indices, one at the injection
+-- end and one here ... this is bases in KE's patches but there is something fishy
+-- there as I'm pretty sure that for husayni we need some connection (as it's much
+-- more complex than an average font) but I need proper examples of all cases, not
+-- of only some.
+
+local a_state            = privateattribute('state')
+local a_markbase         = privateattribute('markbase')
+local a_markmark         = privateattribute('markmark')
+local a_markdone         = privateattribute('markdone') -- assigned at the injection end
+local a_cursbase         = privateattribute('cursbase')
+local a_curscurs         = privateattribute('curscurs')
+local a_cursdone         = privateattribute('cursdone')
+local a_kernpair         = privateattribute('kernpair')
+local a_ligacomp         = privateattribute('ligacomp') -- assigned here (ideally it should be combined)
+
+local injections         = nodes.injections
+local setmark            = injections.setmark
+local setcursive         = injections.setcursive
+local setkern            = injections.setkern
+local setpair            = injections.setpair
+
+local markonce           = true
+local cursonce           = true
+local kernonce           = true
+
+local fonthashes         = fonts.hashes
+local fontdata           = fonthashes.identifiers
+
+local otffeatures        = fonts.constructors.newfeatures("otf")
+local registerotffeature = otffeatures.register
+
+local onetimemessage     = fonts.loggers.onetimemessage or function() end
+
+otf.defaultnodealternate = "none" -- first last
+
+-- we share some vars here, after all, we have no nested lookups and less code
+
+local tfmdata             = false
+local characters          = false
+local descriptions        = false
+local resources           = false
+local marks               = false
+local currentfont         = false
+local lookuptable         = false
+local anchorlookups       = false
+local lookuptypes         = false
+local handlers            = { }
+local rlmode              = 0
+local featurevalue        = false
+
+-- head is always a whatsit so we can safely assume that head is not changed
+
+-- we use this for special testing and documentation
+
+local checkstep       = (nodes and nodes.tracers and nodes.tracers.steppers.check)    or function() end
+local registerstep    = (nodes and nodes.tracers and nodes.tracers.steppers.register) or function() end
+local registermessage = (nodes and nodes.tracers and nodes.tracers.steppers.message)  or function() end
+
+local function logprocess(...)
+    if trace_steps then
+        registermessage(...)
+    end
+    report_direct(...)
+end
+
+local function logwarning(...)
+    report_direct(...)
+end
+
+local f_unicode = formatters["%U"]
+local f_uniname = formatters["%U (%s)"]
+local f_unilist = formatters["% t (% t)"]
+
+local function gref(n) -- currently the same as in font-otb
+    if type(n) == "number" then
+        local description = descriptions[n]
+        local name = description and description.name
+        if name then
+            return f_uniname(n,name)
+        else
+            return f_unicode(n)
+        end
+    elseif n then
+        local num, nam = { }, { }
+        for i=1,#n do
+            local ni = n[i]
+            if tonumber(ni) then -- later we will start at 2
+                local di = descriptions[ni]
+                num[i] = f_unicode(ni)
+                nam[i] = di and di.name or "-"
+            end
+        end
+        return f_unilist(num,nam)
+    else
+        return "<error in node mode tracing>"
+    end
+end
+
+local function cref(kind,chainname,chainlookupname,lookupname,index) -- not in the mood to alias f_
+    if index then
+        return formatters["feature %a, chain %a, sub %a, lookup %a, index %a"](kind,chainname,chainlookupname,lookupname,index)
+    elseif lookupname then
+        return formatters["feature %a, chain %a, sub %a, lookup %a"](kind,chainname,chainlookupname,lookupname)
+    elseif chainlookupname then
+        return formatters["feature %a, chain %a, sub %a"](kind,chainname,chainlookupname)
+    elseif chainname then
+        return formatters["feature %a, chain %a"](kind,chainname)
+    else
+        return formatters["feature %a"](kind)
+    end
+end
+
+local function pref(kind,lookupname)
+    return formatters["feature %a, lookup %a"](kind,lookupname)
+end
+
+-- We can assume that languages that use marks are not hyphenated. We can also assume
+-- that at most one discretionary is present.
+
+-- We do need components in funny kerning mode but maybe I can better reconstruct then
+-- as we do have the font components info available; removing components makes the
+-- previous code much simpler. Also, later on copying and freeing becomes easier.
+-- However, for arabic we need to keep them around for the sake of mark placement
+-- and indices.
+
+local function copy_glyph(g) -- next and prev are untouched !
+    local components = g.components
+    if components then
+        g.components = nil
+        local n = copy_node(g)
+        g.components = components
+        return n
+    else
+        return copy_node(g)
+    end
+end
+
+-- start is a mark and we need to keep that one
+
+local function markstoligature(kind,lookupname,head,start,stop,char)
+    if start == stop and start.char == char then
+        return head, start
+    else
+        local prev = start.prev
+        local next = stop.next
+        start.prev = nil
+        stop.next = nil
+        local base = copy_glyph(start)
+        if head == start then
+            head = base
+        end
+        base.char = char
+        base.subtype = ligature_code
+        base.components = start
+        if prev then
+            prev.next = base
+        end
+        if next then
+            next.prev = base
+        end
+        base.next = next
+        base.prev = prev
+        return head, base
+    end
+end
+
+-- The next code is somewhat complicated by the fact that some fonts can have ligatures made
+-- from ligatures that themselves have marks. This was identified by Kai in for instance
+-- arabtype:  KAF LAM SHADDA ALEF FATHA (0x0643 0x0644 0x0651 0x0627 0x064E). This becomes
+-- KAF LAM-ALEF with a SHADDA on the first and a FATHA op de second component. In a next
+-- iteration this becomes a KAF-LAM-ALEF with a SHADDA on the second and a FATHA on the
+-- third component.
+
+local function getcomponentindex(start)
+    if start.id ~= glyph_code then
+        return 0
+    elseif start.subtype == ligature_code then
+        local i = 0
+        local components = start.components
+        while components do
+            i = i + getcomponentindex(components)
+            components = components.next
+        end
+        return i
+    elseif not marks[start.char] then
+        return 1
+    else
+        return 0
+    end
+end
+
+-- eventually we will do positioning in an other way (needs addional w/h/d fields)
+
+local function toligature(kind,lookupname,head,start,stop,char,markflag,discfound) -- brr head
+    if start == stop and start.char == char then
+        start.char = char
+        return head, start
+    end
+    local prev = start.prev
+    local next = stop.next
+    start.prev = nil
+    stop.next = nil
+    local base = copy_glyph(start)
+    if start == head then
+        head = base
+    end
+    base.char = char
+    base.subtype = ligature_code
+    base.components = start -- start can have components
+    if prev then
+        prev.next = base
+    end
+    if next then
+        next.prev = base
+    end
+    base.next = next
+    base.prev = prev
+    if not discfound then
+        local deletemarks = markflag ~= "mark"
+        local components = start
+        local baseindex = 0
+        local componentindex = 0
+        local head = base
+        local current = base
+        -- first we loop over the glyphs in start .. stop
+        while start do
+            local char = start.char
+            if not marks[char] then
+                baseindex = baseindex + componentindex
+                componentindex = getcomponentindex(start)
+            elseif not deletemarks then -- quite fishy
+                start[a_ligacomp] = baseindex + (start[a_ligacomp] or componentindex)
+                if trace_marks then
+                    logwarning("%s: keep mark %s, gets index %s",pref(kind,lookupname),gref(char),start[a_ligacomp])
+                end
+                head, current = insert_node_after(head,current,copy_node(start)) -- unlikely that mark has components
+            elseif trace_marks then
+                logwarning("%s: delete mark %s",pref(kind,lookupname),gref(char))
+            end
+            start = start.next
+        end
+        -- we can have one accent as part of a lookup and another following
+     -- local start = components -- was wrong (component scanning was introduced when more complex ligs in devanagari was added)
+        local start = current.next
+        while start and start.id == glyph_code do
+            local char = start.char
+            if marks[char] then
+                start[a_ligacomp] = baseindex + (start[a_ligacomp] or componentindex)
+                if trace_marks then
+                    logwarning("%s: set mark %s, gets index %s",pref(kind,lookupname),gref(char),start[a_ligacomp])
+                end
+            else
+                break
+            end
+            start = start.next
+        end
+    end
+    return head, base
+end
+
+function handlers.gsub_single(head,start,kind,lookupname,replacement)
+    if trace_singles then
+        logprocess("%s: replacing %s by single %s",pref(kind,lookupname),gref(start.char),gref(replacement))
+    end
+    start.char = replacement
+    return head, start, true
+end
+
+local function get_alternative_glyph(start,alternatives,value,trace_alternatives)
+    local n = #alternatives
+    if value == "random" then
+        local r = random(1,n)
+        return alternatives[r], trace_alternatives and formatters["value %a, taking %a"](value,r)
+    elseif value == "first" then
+        return alternatives[1], trace_alternatives and formatters["value %a, taking %a"](value,1)
+    elseif value == "last" then
+        return alternatives[n], trace_alternatives and formatters["value %a, taking %a"](value,n)
+    else
+        value = tonumber(value)
+        if type(value) ~= "number" then
+            return alternatives[1], trace_alternatives and formatters["invalid value %s, taking %a"](value,1)
+        elseif value > n then
+            local defaultalt = otf.defaultnodealternate
+            if defaultalt == "first" then
+                return alternatives[n], trace_alternatives and formatters["invalid value %s, taking %a"](value,1)
+            elseif defaultalt == "last" then
+                return alternatives[1], trace_alternatives and formatters["invalid value %s, taking %a"](value,n)
+            else
+                return false, trace_alternatives and formatters["invalid value %a, %s"](value,"out of range")
+            end
+        elseif value == 0 then
+            return start.char, trace_alternatives and formatters["invalid value %a, %s"](value,"no change")
+        elseif value < 1 then
+            return alternatives[1], trace_alternatives and formatters["invalid value %a, taking %a"](value,1)
+        else
+            return alternatives[value], trace_alternatives and formatters["value %a, taking %a"](value,value)
+        end
+    end
+end
+
+local function multiple_glyphs(head,start,multiple,ignoremarks)
+    local nofmultiples = #multiple
+    if nofmultiples > 0 then
+        start.char = multiple[1]
+        if nofmultiples > 1 then
+            local sn = start.next
+            for k=2,nofmultiples do -- todo: use insert_node
+-- untested:
+--
+-- while ignoremarks and marks[sn.char] then
+--     local sn = sn.next
+-- end
+                local n = copy_node(start) -- ignore components
+                n.char = multiple[k]
+                n.next = sn
+                n.prev = start
+                if sn then
+                    sn.prev = n
+                end
+                start.next = n
+                start = n
+            end
+        end
+        return head, start, true
+    else
+        if trace_multiples then
+            logprocess("no multiple for %s",gref(start.char))
+        end
+        return head, start, false
+    end
+end
+
+function handlers.gsub_alternate(head,start,kind,lookupname,alternative,sequence)
+    local value = featurevalue == true and tfmdata.shared.features[kind] or featurevalue
+    local choice, comment = get_alternative_glyph(start,alternative,value,trace_alternatives)
+    if choice then
+        if trace_alternatives then
+            logprocess("%s: replacing %s by alternative %a to %s, %s",pref(kind,lookupname),gref(start.char),choice,gref(choice),comment)
+        end
+        start.char = choice
+    else
+        if trace_alternatives then
+            logwarning("%s: no variant %a for %s, %s",pref(kind,lookupname),value,gref(start.char),comment)
+        end
+    end
+    return head, start, true
+end
+
+function handlers.gsub_multiple(head,start,kind,lookupname,multiple,sequence)
+    if trace_multiples then
+        logprocess("%s: replacing %s by multiple %s",pref(kind,lookupname),gref(start.char),gref(multiple))
+    end
+    return multiple_glyphs(head,start,multiple,sequence.flags[1])
+end
+
+function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
+    local s, stop, discfound = start.next, nil, false
+    local startchar = start.char
+    if marks[startchar] then
+        while s do
+            local id = s.id
+            if id == glyph_code and s.font == currentfont and s.subtype<256 then
+                local lg = ligature[s.char]
+                if lg then
+                    stop = s
+                    ligature = lg
+                    s = s.next
+                else
+                    break
+                end
+            else
+                break
+            end
+        end
+        if stop then
+            local lig = ligature.ligature
+            if lig then
+                if trace_ligatures then
+                    local stopchar = stop.char
+                    head, start = markstoligature(kind,lookupname,head,start,stop,lig)
+                    logprocess("%s: replacing %s upto %s by ligature %s case 1",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(start.char))
+                else
+                    head, start = markstoligature(kind,lookupname,head,start,stop,lig)
+                end
+                return head, start, true
+            else
+                -- ok, goto next lookup
+            end
+        end
+    else
+        local skipmark = sequence.flags[1]
+        while s do
+            local id = s.id
+            if id == glyph_code and s.subtype<256 then
+                if s.font == currentfont then
+                    local char = s.char
+                    if skipmark and marks[char] then
+                        s = s.next
+                    else
+                        local lg = ligature[char]
+                        if lg then
+                            stop = s
+                            ligature = lg
+                            s = s.next
+                        else
+                            break
+                        end
+                    end
+                else
+                    break
+                end
+            elseif id == disc_code then
+                discfound = true
+                s = s.next
+            else
+                break
+            end
+        end
+        local lig = ligature.ligature
+        if lig then
+            if stop then
+                if trace_ligatures then
+                    local stopchar = stop.char
+                    head, start = toligature(kind,lookupname,head,start,stop,lig,skipmark,discfound)
+                    logprocess("%s: replacing %s upto %s by ligature %s case 2",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(start.char))
+                else
+                    head, start = toligature(kind,lookupname,head,start,stop,lig,skipmark,discfound)
+                end
+                return head, start, true
+            else
+                -- weird but happens (in some arabic font)
+                start.char = lig
+                if trace_ligatures then
+                    logprocess("%s: replacing %s by (no real) ligature %s case 3",pref(kind,lookupname),gref(startchar),gref(lig))
+                end
+                return head, start, true
+            end
+        else
+            -- weird but happens
+        end
+    end
+    return head, start, false
+end
+
+--[[ldx--
+<p>We get hits on a mark, but we're not sure if the it has to be applied so
+we need to explicitly test for basechar, baselig and basemark entries.</p>
+--ldx]]--
+
+function handlers.gpos_mark2base(head,start,kind,lookupname,markanchors,sequence)
+    local markchar = start.char
+    if marks[markchar] then
+        local base = start.prev -- [glyph] [start=mark]
+        if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+            local basechar = base.char
+            if marks[basechar] then
+                while true do
+                    base = base.prev
+                    if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+                        basechar = base.char
+                        if not marks[basechar] then
+                            break
+                        end
+                    else
+                        if trace_bugs then
+                            logwarning("%s: no base for mark %s",pref(kind,lookupname),gref(markchar))
+                        end
+                        return head, start, false
+                    end
+                end
+            end
+            local baseanchors = descriptions[basechar]
+            if baseanchors then
+                baseanchors = baseanchors.anchors
+            end
+            if baseanchors then
+                local baseanchors = baseanchors['basechar']
+                if baseanchors then
+                    local al = anchorlookups[lookupname]
+                    for anchor,ba in next, baseanchors do
+                        if al[anchor] then
+                            local ma = markanchors[anchor]
+                            if ma then
+                                local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma)
+                                if trace_marks then
+                                    logprocess("%s, anchor %s, bound %s: anchoring mark %s to basechar %s => (%p,%p)",
+                                        pref(kind,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+                                end
+                                return head, start, true
+                            end
+                        end
+                    end
+                    if trace_bugs then
+                        logwarning("%s, no matching anchors for mark %s and base %s",pref(kind,lookupname),gref(markchar),gref(basechar))
+                    end
+                end
+            elseif trace_bugs then
+            --  logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(basechar))
+                onetimemessage(currentfont,basechar,"no base anchors",report_fonts)
+            end
+        elseif trace_bugs then
+            logwarning("%s: prev node is no char",pref(kind,lookupname))
+        end
+    elseif trace_bugs then
+        logwarning("%s: mark %s is no mark",pref(kind,lookupname),gref(markchar))
+    end
+    return head, start, false
+end
+
+function handlers.gpos_mark2ligature(head,start,kind,lookupname,markanchors,sequence)
+    -- check chainpos variant
+    local markchar = start.char
+    if marks[markchar] then
+        local base = start.prev -- [glyph] [optional marks] [start=mark]
+        if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+            local basechar = base.char
+            if marks[basechar] then
+                while true do
+                    base = base.prev
+                    if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+                        basechar = base.char
+                        if not marks[basechar] then
+                            break
+                        end
+                    else
+                        if trace_bugs then
+                            logwarning("%s: no base for mark %s",pref(kind,lookupname),gref(markchar))
+                        end
+                        return head, start, false
+                    end
+                end
+            end
+            local index = start[a_ligacomp]
+            local baseanchors = descriptions[basechar]
+            if baseanchors then
+                baseanchors = baseanchors.anchors
+                if baseanchors then
+                   local baseanchors = baseanchors['baselig']
+                   if baseanchors then
+                        local al = anchorlookups[lookupname]
+                        for anchor, ba in next, baseanchors do
+                            if al[anchor] then
+                                local ma = markanchors[anchor]
+                                if ma then
+                                    ba = ba[index]
+                                    if ba then
+                                        local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma) -- index
+                                        if trace_marks then
+                                            logprocess("%s, anchor %s, index %s, bound %s: anchoring mark %s to baselig %s at index %s => (%p,%p)",
+                                                pref(kind,lookupname),anchor,index,bound,gref(markchar),gref(basechar),index,dx,dy)
+                                        end
+                                        return head, start, true
+                                    else
+                                        if trace_bugs then
+                                            logwarning("%s: no matching anchors for mark %s and baselig %s with index %a",pref(kind,lookupname),gref(markchar),gref(basechar),index)
+                                        end
+                                    end
+                                end
+                            end
+                        end
+                        if trace_bugs then
+                            logwarning("%s: no matching anchors for mark %s and baselig %s",pref(kind,lookupname),gref(markchar),gref(basechar))
+                        end
+                    end
+                end
+            elseif trace_bugs then
+            --  logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(basechar))
+                onetimemessage(currentfont,basechar,"no base anchors",report_fonts)
+            end
+        elseif trace_bugs then
+            logwarning("%s: prev node is no char",pref(kind,lookupname))
+        end
+    elseif trace_bugs then
+        logwarning("%s: mark %s is no mark",pref(kind,lookupname),gref(markchar))
+    end
+    return head, start, false
+end
+
+function handlers.gpos_mark2mark(head,start,kind,lookupname,markanchors,sequence)
+    local markchar = start.char
+    if marks[markchar] then
+        local base = start.prev -- [glyph] [basemark] [start=mark]
+        local slc = start[a_ligacomp]
+        if slc then -- a rather messy loop ... needs checking with husayni
+            while base do
+                local blc = base[a_ligacomp]
+                if blc and blc ~= slc then
+                    base = base.prev
+                else
+                    break
+                end
+            end
+        end
+        if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then -- subtype test can go
+            local basechar = base.char
+            local baseanchors = descriptions[basechar]
+            if baseanchors then
+                baseanchors = baseanchors.anchors
+                if baseanchors then
+                    baseanchors = baseanchors['basemark']
+                    if baseanchors then
+                        local al = anchorlookups[lookupname]
+                        for anchor,ba in next, baseanchors do
+                            if al[anchor] then
+                                local ma = markanchors[anchor]
+                                if ma then
+                                    local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma,true)
+                                    if trace_marks then
+                                        logprocess("%s, anchor %s, bound %s: anchoring mark %s to basemark %s => (%p,%p)",
+                                            pref(kind,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+                                    end
+                                    return head, start, true
+                                end
+                            end
+                        end
+                        if trace_bugs then
+                            logwarning("%s: no matching anchors for mark %s and basemark %s",pref(kind,lookupname),gref(markchar),gref(basechar))
+                        end
+                    end
+                end
+            elseif trace_bugs then
+            --  logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(basechar))
+                onetimemessage(currentfont,basechar,"no base anchors",report_fonts)
+            end
+        elseif trace_bugs then
+            logwarning("%s: prev node is no mark",pref(kind,lookupname))
+        end
+    elseif trace_bugs then
+        logwarning("%s: mark %s is no mark",pref(kind,lookupname),gref(markchar))
+    end
+    return head, start, false
+end
+
+function handlers.gpos_cursive(head,start,kind,lookupname,exitanchors,sequence) -- to be checked
+    local alreadydone = cursonce and start[a_cursbase]
+    if not alreadydone then
+        local done = false
+        local startchar = start.char
+        if marks[startchar] then
+            if trace_cursive then
+                logprocess("%s: ignoring cursive for mark %s",pref(kind,lookupname),gref(startchar))
+            end
+        else
+            local nxt = start.next
+            while not done and nxt and nxt.id == glyph_code and nxt.font == currentfont and nxt.subtype<256 do
+                local nextchar = nxt.char
+                if marks[nextchar] then
+                    -- should not happen (maybe warning)
+                    nxt = nxt.next
+                else
+                    local entryanchors = descriptions[nextchar]
+                    if entryanchors then
+                        entryanchors = entryanchors.anchors
+                        if entryanchors then
+                            entryanchors = entryanchors['centry']
+                            if entryanchors then
+                                local al = anchorlookups[lookupname]
+                                for anchor, entry in next, entryanchors do
+                                    if al[anchor] then
+                                        local exit = exitanchors[anchor]
+                                        if exit then
+                                            local dx, dy, bound = setcursive(start,nxt,tfmdata.parameters.factor,rlmode,exit,entry,characters[startchar],characters[nextchar])
+                                            if trace_cursive then
+                                                logprocess("%s: moving %s to %s cursive (%p,%p) using anchor %s and bound %s in rlmode %s",pref(kind,lookupname),gref(startchar),gref(nextchar),dx,dy,anchor,bound,rlmode)
+                                            end
+                                            done = true
+                                            break
+                                        end
+                                    end
+                                end
+                            end
+                        end
+                    elseif trace_bugs then
+                    --  logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(startchar))
+                        onetimemessage(currentfont,startchar,"no entry anchors",report_fonts)
+                    end
+                    break
+                end
+            end
+        end
+        return head, start, done
+    else
+        if trace_cursive and trace_details then
+            logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(start.char),alreadydone)
+        end
+        return head, start, false
+    end
+end
+
+function handlers.gpos_single(head,start,kind,lookupname,kerns,sequence)
+    local startchar = start.char
+    local dx, dy, w, h = setpair(start,tfmdata.parameters.factor,rlmode,sequence.flags[4],kerns,characters[startchar])
+    if trace_kerns then
+        logprocess("%s: shifting single %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),dx,dy,w,h)
+    end
+    return head, start, false
+end
+
+function handlers.gpos_pair(head,start,kind,lookupname,kerns,sequence)
+    -- todo: kerns in disc nodes: pre, post, replace -> loop over disc too
+    -- todo: kerns in components of ligatures
+    local snext = start.next
+    if not snext then
+        return head, start, false
+    else
+        local prev, done = start, false
+        local factor = tfmdata.parameters.factor
+        local lookuptype = lookuptypes[lookupname]
+        while snext and snext.id == glyph_code and snext.font == currentfont and snext.subtype<256 do
+            local nextchar = snext.char
+            local krn = kerns[nextchar]
+            if not krn and marks[nextchar] then
+                prev = snext
+                snext = snext.next
+            else
+                if not krn then
+                    -- skip
+                elseif type(krn) == "table" then
+                    if lookuptype == "pair" then -- probably not needed
+                        local a, b = krn[2], krn[3]
+                        if a and #a > 0 then
+                            local startchar = start.char
+                            local x, y, w, h = setpair(start,factor,rlmode,sequence.flags[4],a,characters[startchar])
+                            if trace_kerns then
+                                logprocess("%s: shifting first of pair %s and %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),gref(nextchar),x,y,w,h)
+                            end
+                        end
+                        if b and #b > 0 then
+                            local startchar = start.char
+                            local x, y, w, h = setpair(snext,factor,rlmode,sequence.flags[4],b,characters[nextchar])
+                            if trace_kerns then
+                                logprocess("%s: shifting second of pair %s and %s by (%p,%p) and correction (%p,%p)",pref(kind,lookupname),gref(startchar),gref(nextchar),x,y,w,h)
+                            end
+                        end
+                    else -- wrong ... position has different entries
+                        report_process("%s: check this out (old kern stuff)",pref(kind,lookupname))
+                     -- local a, b = krn[2], krn[6]
+                     -- if a and a ~= 0 then
+                     --     local k = setkern(snext,factor,rlmode,a)
+                     --     if trace_kerns then
+                     --         logprocess("%s: inserting first kern %s between %s and %s",pref(kind,lookupname),k,gref(prev.char),gref(nextchar))
+                     --     end
+                     -- end
+                     -- if b and b ~= 0 then
+                     --     logwarning("%s: ignoring second kern xoff %s",pref(kind,lookupname),b*factor)
+                     -- end
+                    end
+                    done = true
+                elseif krn ~= 0 then
+                    local k = setkern(snext,factor,rlmode,krn)
+                    if trace_kerns then
+                        logprocess("%s: inserting kern %s between %s and %s",pref(kind,lookupname),k,gref(prev.char),gref(nextchar))
+                    end
+                    done = true
+                end
+                break
+            end
+        end
+        return head, start, done
+    end
+end
+
+--[[ldx--
+<p>I will implement multiple chain replacements once I run into a font that uses
+it. It's not that complex to handle.</p>
+--ldx]]--
+
+local chainmores = { }
+local chainprocs = { }
+
+local function logprocess(...)
+    if trace_steps then
+        registermessage(...)
+    end
+    report_subchain(...)
+end
+
+local logwarning = report_subchain
+
+local function logprocess(...)
+    if trace_steps then
+        registermessage(...)
+    end
+    report_chain(...)
+end
+
+local logwarning = report_chain
+
+-- We could share functions but that would lead to extra function calls with many
+-- arguments, redundant tests and confusing messages.
+
+function chainprocs.chainsub(head,start,stop,kind,chainname,currentcontext,lookuphash,lookuplist,chainlookupname)
+    logwarning("%s: a direct call to chainsub cannot happen",cref(kind,chainname,chainlookupname))
+    return head, start, false
+end
+
+function chainmores.chainsub(head,start,stop,kind,chainname,currentcontext,lookuphash,lookuplist,chainlookupname,n)
+    logprocess("%s: a direct call to chainsub cannot happen",cref(kind,chainname,chainlookupname))
+    return head, start, false
+end
+
+-- The reversesub is a special case, which is why we need to store the replacements
+-- in a bit weird way. There is no lookup and the replacement comes from the lookup
+-- itself. It is meant mostly for dealing with Urdu.
+
+function chainprocs.reversesub(head,start,stop,kind,chainname,currentcontext,lookuphash,replacements)
+    local char = start.char
+    local replacement = replacements[char]
+    if replacement then
+        if trace_singles then
+            logprocess("%s: single reverse replacement of %s by %s",cref(kind,chainname),gref(char),gref(replacement))
+        end
+        start.char = replacement
+        return head, start, true
+    else
+        return head, start, false
+    end
+end
+
+--[[ldx--
+<p>This chain stuff is somewhat tricky since we can have a sequence of actions to be
+applied: single, alternate, multiple or ligature where ligature can be an invalid
+one in the sense that it will replace multiple by one but not neccessary one that
+looks like the combination (i.e. it is the counterpart of multiple then). For
+example, the following is valid:</p>
+
+<typing>
+<line>xxxabcdexxx [single a->A][multiple b->BCD][ligature cde->E] xxxABCDExxx</line>
+</typing>
+
+<p>Therefore we we don't really do the replacement here already unless we have the
+single lookup case. The efficiency of the replacements can be improved by deleting
+as less as needed but that would also make the code even more messy.</p>
+--ldx]]--
+
+-- local function delete_till_stop(head,start,stop,ignoremarks) -- keeps start
+--     local n = 1
+--     if start == stop then
+--         -- done
+--     elseif ignoremarks then
+--         repeat -- start x x m x x stop => start m
+--             local next = start.next
+--             if not marks[next.char] then
+--                 local components = next.components
+--                 if components then -- probably not needed
+--                     flush_node_list(components)
+--                 end
+--                 head = delete_node(head,next)
+--             end
+--             n = n + 1
+--         until next == stop
+--     else -- start x x x stop => start
+--         repeat
+--             local next = start.next
+--             local components = next.components
+--             if components then -- probably not needed
+--                 flush_node_list(components)
+--             end
+--             head = delete_node(head,next)
+--             n = n + 1
+--         until next == stop
+--     end
+--     return head, n
+-- end
+
+--[[ldx--
+<p>Here we replace start by a single variant, First we delete the rest of the
+match.</p>
+--ldx]]--
+
+function chainprocs.gsub_single(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex)
+    -- todo: marks ?
+    local current = start
+    local subtables = currentlookup.subtables
+    if #subtables > 1 then
+        logwarning("todo: check if we need to loop over the replacements: %s",concat(subtables," "))
+    end
+    while current do
+        if current.id == glyph_code then
+            local currentchar = current.char
+            local lookupname = subtables[1] -- only 1
+            local replacement = lookuphash[lookupname]
+            if not replacement then
+                if trace_bugs then
+                    logwarning("%s: no single hits",cref(kind,chainname,chainlookupname,lookupname,chainindex))
+                end
+            else
+                replacement = replacement[currentchar]
+                if not replacement or replacement == "" then
+                    if trace_bugs then
+                        logwarning("%s: no single for %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(currentchar))
+                    end
+                else
+                    if trace_singles then
+                        logprocess("%s: replacing single %s by %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(currentchar),gref(replacement))
+                    end
+                    current.char = replacement
+                end
+            end
+            return head, start, true
+        elseif current == stop then
+            break
+        else
+            current = current.next
+        end
+    end
+    return head, start, false
+end
+
+chainmores.gsub_single = chainprocs.gsub_single
+
+--[[ldx--
+<p>Here we replace start by a sequence of new glyphs. First we delete the rest of
+the match.</p>
+--ldx]]--
+
+function chainprocs.gsub_multiple(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+ -- local head, n = delete_till_stop(head,start,stop)
+    local startchar = start.char
+    local subtables = currentlookup.subtables
+    local lookupname = subtables[1]
+    local replacements = lookuphash[lookupname]
+    if not replacements then
+        if trace_bugs then
+            logwarning("%s: no multiple hits",cref(kind,chainname,chainlookupname,lookupname))
+        end
+    else
+        replacements = replacements[startchar]
+        if not replacements or replacement == "" then
+            if trace_bugs then
+                logwarning("%s: no multiple for %s",cref(kind,chainname,chainlookupname,lookupname),gref(startchar))
+            end
+        else
+            if trace_multiples then
+                logprocess("%s: replacing %s by multiple characters %s",cref(kind,chainname,chainlookupname,lookupname),gref(startchar),gref(replacements))
+            end
+            return multiple_glyphs(head,start,replacements,currentlookup.flags[1])
+        end
+    end
+    return head, start, false
+end
+
+chainmores.gsub_multiple = chainprocs.gsub_multiple
+
+--[[ldx--
+<p>Here we replace start by new glyph. First we delete the rest of the match.</p>
+--ldx]]--
+
+-- char_1 mark_1 -> char_x mark_1 (ignore marks)
+-- char_1 mark_1 -> char_x
+
+-- to be checked: do we always have just one glyph?
+-- we can also have alternates for marks
+-- marks come last anyway
+-- are there cases where we need to delete the mark
+
+function chainprocs.gsub_alternate(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+    local current = start
+    local subtables = currentlookup.subtables
+    local value  = featurevalue == true and tfmdata.shared.features[kind] or featurevalue
+    while current do
+        if current.id == glyph_code then -- is this check needed?
+            local currentchar = current.char
+            local lookupname = subtables[1]
+            local alternatives = lookuphash[lookupname]
+            if not alternatives then
+                if trace_bugs then
+                    logwarning("%s: no alternative hit",cref(kind,chainname,chainlookupname,lookupname))
+                end
+            else
+                alternatives = alternatives[currentchar]
+                if alternatives then
+                    local choice, comment = get_alternative_glyph(current,alternatives,value,trace_alternatives)
+                    if choice then
+                        if trace_alternatives then
+                            logprocess("%s: replacing %s by alternative %a to %s, %s",cref(kind,chainname,chainlookupname,lookupname),gref(char),choice,gref(choice),comment)
+                        end
+                        start.char = choice
+                    else
+                        if trace_alternatives then
+                            logwarning("%s: no variant %a for %s, %s",cref(kind,chainname,chainlookupname,lookupname),value,gref(char),comment)
+                        end
+                    end
+                elseif trace_bugs then
+                    logwarning("%s: no alternative for %s, %s",cref(kind,chainname,chainlookupname,lookupname),gref(currentchar),comment)
+                end
+            end
+            return head, start, true
+        elseif current == stop then
+            break
+        else
+            current = current.next
+        end
+    end
+    return head, start, false
+end
+
+chainmores.gsub_alternate = chainprocs.gsub_alternate
+
+--[[ldx--
+<p>When we replace ligatures we use a helper that handles the marks. I might change
+this function (move code inline and handle the marks by a separate function). We
+assume rather stupid ligatures (no complex disc nodes).</p>
+--ldx]]--
+
+function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex)
+    local startchar = start.char
+    local subtables = currentlookup.subtables
+    local lookupname = subtables[1]
+    local ligatures = lookuphash[lookupname]
+    if not ligatures then
+        if trace_bugs then
+            logwarning("%s: no ligature hits",cref(kind,chainname,chainlookupname,lookupname,chainindex))
+        end
+    else
+        ligatures = ligatures[startchar]
+        if not ligatures then
+            if trace_bugs then
+                logwarning("%s: no ligatures starting with %s",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar))
+            end
+        else
+            local s = start.next
+            local discfound = false
+            local last = stop
+            local nofreplacements = 0
+            local skipmark = currentlookup.flags[1]
+            while s do
+                local id = s.id
+                if id == disc_code then
+                    s = s.next
+                    discfound = true
+                else
+                    local schar = s.char
+                    if skipmark and marks[schar] then -- marks
+                        s = s.next
+                    else
+                        local lg = ligatures[schar]
+                        if lg then
+                            ligatures, last, nofreplacements = lg, s, nofreplacements + 1
+                            if s == stop then
+                                break
+                            else
+                                s = s.next
+                            end
+                        else
+                            break
+                        end
+                    end
+                end
+            end
+            local l2 = ligatures.ligature
+            if l2 then
+                if chainindex then
+                    stop = last
+                end
+                if trace_ligatures then
+                    if start == stop then
+                        logprocess("%s: replacing character %s by ligature %s case 3",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(l2))
+                    else
+                        logprocess("%s: replacing character %s upto %s by ligature %s case 4",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(stop.char),gref(l2))
+                    end
+                end
+                head, start = toligature(kind,lookupname,head,start,stop,l2,currentlookup.flags[1],discfound)
+                return head, start, true, nofreplacements
+            elseif trace_bugs then
+                if start == stop then
+                    logwarning("%s: replacing character %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar))
+                else
+                    logwarning("%s: replacing character %s upto %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(stop.char))
+                end
+            end
+        end
+    end
+    return head, start, false, 0
+end
+
+chainmores.gsub_ligature = chainprocs.gsub_ligature
+
+function chainprocs.gpos_mark2base(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+    local markchar = start.char
+    if marks[markchar] then
+        local subtables = currentlookup.subtables
+        local lookupname = subtables[1]
+        local markanchors = lookuphash[lookupname]
+        if markanchors then
+            markanchors = markanchors[markchar]
+        end
+        if markanchors then
+            local base = start.prev -- [glyph] [start=mark]
+            if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+                local basechar = base.char
+                if marks[basechar] then
+                    while true do
+                        base = base.prev
+                        if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+                            basechar = base.char
+                            if not marks[basechar] then
+                                break
+                            end
+                        else
+                            if trace_bugs then
+                                logwarning("%s: no base for mark %s",pref(kind,lookupname),gref(markchar))
+                            end
+                            return head, start, false
+                        end
+                    end
+                end
+                local baseanchors = descriptions[basechar].anchors
+                if baseanchors then
+                    local baseanchors = baseanchors['basechar']
+                    if baseanchors then
+                        local al = anchorlookups[lookupname]
+                        for anchor,ba in next, baseanchors do
+                            if al[anchor] then
+                                local ma = markanchors[anchor]
+                                if ma then
+                                    local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma)
+                                    if trace_marks then
+                                        logprocess("%s, anchor %s, bound %s: anchoring mark %s to basechar %s => (%p,%p)",
+                                            cref(kind,chainname,chainlookupname,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+                                    end
+                                    return head, start, true
+                                end
+                            end
+                        end
+                        if trace_bugs then
+                            logwarning("%s, no matching anchors for mark %s and base %s",cref(kind,chainname,chainlookupname,lookupname),gref(markchar),gref(basechar))
+                        end
+                    end
+                end
+            elseif trace_bugs then
+                logwarning("%s: prev node is no char",cref(kind,chainname,chainlookupname,lookupname))
+            end
+        elseif trace_bugs then
+            logwarning("%s: mark %s has no anchors",cref(kind,chainname,chainlookupname,lookupname),gref(markchar))
+        end
+    elseif trace_bugs then
+        logwarning("%s: mark %s is no mark",cref(kind,chainname,chainlookupname),gref(markchar))
+    end
+    return head, start, false
+end
+
+function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+    local markchar = start.char
+    if marks[markchar] then
+        local subtables = currentlookup.subtables
+        local lookupname = subtables[1]
+        local markanchors = lookuphash[lookupname]
+        if markanchors then
+            markanchors = markanchors[markchar]
+        end
+        if markanchors then
+            local base = start.prev -- [glyph] [optional marks] [start=mark]
+            if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+                local basechar = base.char
+                if marks[basechar] then
+                    while true do
+                        base = base.prev
+                        if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then
+                            basechar = base.char
+                            if not marks[basechar] then
+                                break
+                            end
+                        else
+                            if trace_bugs then
+                                logwarning("%s: no base for mark %s",cref(kind,chainname,chainlookupname,lookupname),markchar)
+                            end
+                            return head, start, false
+                        end
+                    end
+                end
+                -- todo: like marks a ligatures hash
+                local index = start[a_ligacomp]
+                local baseanchors = descriptions[basechar].anchors
+                if baseanchors then
+                   local baseanchors = baseanchors['baselig']
+                   if baseanchors then
+                        local al = anchorlookups[lookupname]
+                        for anchor,ba in next, baseanchors do
+                            if al[anchor] then
+                                local ma = markanchors[anchor]
+                                if ma then
+                                    ba = ba[index]
+                                    if ba then
+                                        local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma) -- index
+                                        if trace_marks then
+                                            logprocess("%s, anchor %s, bound %s: anchoring mark %s to baselig %s at index %s => (%p,%p)",
+                                                cref(kind,chainname,chainlookupname,lookupname),anchor,a or bound,gref(markchar),gref(basechar),index,dx,dy)
+                                        end
+                                        return head, start, true
+                                    end
+                                end
+                            end
+                        end
+                        if trace_bugs then
+                            logwarning("%s: no matching anchors for mark %s and baselig %s",cref(kind,chainname,chainlookupname,lookupname),gref(markchar),gref(basechar))
+                        end
+                    end
+                end
+            elseif trace_bugs then
+                logwarning("feature %s, lookup %s: prev node is no char",kind,lookupname)
+            end
+        elseif trace_bugs then
+            logwarning("%s: mark %s has no anchors",cref(kind,chainname,chainlookupname,lookupname),gref(markchar))
+        end
+    elseif trace_bugs then
+        logwarning("%s: mark %s is no mark",cref(kind,chainname,chainlookupname),gref(markchar))
+    end
+    return head, start, false
+end
+
+function chainprocs.gpos_mark2mark(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+    local markchar = start.char
+    if marks[markchar] then
+     -- local alreadydone = markonce and start[a_markmark]
+     -- if not alreadydone then
+        --  local markanchors = descriptions[markchar].anchors markanchors = markanchors and markanchors.mark
+            local subtables = currentlookup.subtables
+            local lookupname = subtables[1]
+            local markanchors = lookuphash[lookupname]
+            if markanchors then
+                markanchors = markanchors[markchar]
+            end
+            if markanchors then
+                local base = start.prev -- [glyph] [basemark] [start=mark]
+                local slc = start[a_ligacomp]
+                if slc then -- a rather messy loop ... needs checking with husayni
+                    while base do
+                        local blc = base[a_ligacomp]
+                        if blc and blc ~= slc then
+                            base = base.prev
+                        else
+                            break
+                        end
+                    end
+                end
+                if base and base.id == glyph_code and base.font == currentfont and base.subtype<256 then -- subtype test can go
+                    local basechar = base.char
+                    local baseanchors = descriptions[basechar].anchors
+                    if baseanchors then
+                        baseanchors = baseanchors['basemark']
+                        if baseanchors then
+                            local al = anchorlookups[lookupname]
+                            for anchor,ba in next, baseanchors do
+                                if al[anchor] then
+                                    local ma = markanchors[anchor]
+                                    if ma then
+                                        local dx, dy, bound = setmark(start,base,tfmdata.parameters.factor,rlmode,ba,ma,true)
+                                        if trace_marks then
+                                            logprocess("%s, anchor %s, bound %s: anchoring mark %s to basemark %s => (%p,%p)",
+                                                cref(kind,chainname,chainlookupname,lookupname),anchor,bound,gref(markchar),gref(basechar),dx,dy)
+                                        end
+                                        return head, start, true
+                                    end
+                                end
+                            end
+                            if trace_bugs then
+                                logwarning("%s: no matching anchors for mark %s and basemark %s",gref(kind,chainname,chainlookupname,lookupname),gref(markchar),gref(basechar))
+                            end
+                        end
+                    end
+                elseif trace_bugs then
+                    logwarning("%s: prev node is no mark",cref(kind,chainname,chainlookupname,lookupname))
+                end
+            elseif trace_bugs then
+                logwarning("%s: mark %s has no anchors",cref(kind,chainname,chainlookupname,lookupname),gref(markchar))
+            end
+     -- elseif trace_marks and trace_details then
+     --     logprocess("%s, mark %s is already bound (n=%s), ignoring mark2mark",pref(kind,lookupname),gref(markchar),alreadydone)
+     -- end
+    elseif trace_bugs then
+        logwarning("%s: mark %s is no mark",cref(kind,chainname,chainlookupname),gref(markchar))
+    end
+    return head, start, false
+end
+
+function chainprocs.gpos_cursive(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname)
+    local alreadydone = cursonce and start[a_cursbase]
+    if not alreadydone then
+        local startchar = start.char
+        local subtables = currentlookup.subtables
+        local lookupname = subtables[1]
+        local exitanchors = lookuphash[lookupname]
+        if exitanchors then
+            exitanchors = exitanchors[startchar]
+        end
+        if exitanchors then
+            local done = false
+            if marks[startchar] then
+                if trace_cursive then
+                    logprocess("%s: ignoring cursive for mark %s",pref(kind,lookupname),gref(startchar))
+                end
+            else
+                local nxt = start.next
+                while not done and nxt and nxt.id == glyph_code and nxt.font == currentfont and nxt.subtype<256 do
+                    local nextchar = nxt.char
+                    if marks[nextchar] then
+                        -- should not happen (maybe warning)
+                        nxt = nxt.next
+                    else
+                        local entryanchors = descriptions[nextchar]
+                        if entryanchors then
+                            entryanchors = entryanchors.anchors
+                            if entryanchors then
+                                entryanchors = entryanchors['centry']
+                                if entryanchors then
+                                    local al = anchorlookups[lookupname]
+                                    for anchor, entry in next, entryanchors do
+                                        if al[anchor] then
+                                            local exit = exitanchors[anchor]
+                                            if exit then
+                                                local dx, dy, bound = setcursive(start,nxt,tfmdata.parameters.factor,rlmode,exit,entry,characters[startchar],characters[nextchar])
+                                                if trace_cursive then
+                                                    logprocess("%s: moving %s to %s cursive (%p,%p) using anchor %s and bound %s in rlmode %s",pref(kind,lookupname),gref(startchar),gref(nextchar),dx,dy,anchor,bound,rlmode)
+                                                end
+                                                done = true
+                                                break
+                                            end
+                                        end
+                                    end
+                                end
+                            end
+                        elseif trace_bugs then
+                        --  logwarning("%s: char %s is missing in font",pref(kind,lookupname),gref(startchar))
+                            onetimemessage(currentfont,startchar,"no entry anchors",report_fonts)
+                        end
+                        break
+                    end
+                end
+            end
+            return head, start, done
+        else
+            if trace_cursive and trace_details then
+                logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(start.char),alreadydone)
+            end
+            return head, start, false
+        end
+    end
+    return head, start, false
+end
+
+function chainprocs.gpos_single(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex,sequence)
+    -- untested .. needs checking for the new model
+    local startchar = start.char
+    local subtables = currentlookup.subtables
+    local lookupname = subtables[1]
+    local kerns = lookuphash[lookupname]
+    if kerns then
+        kerns = kerns[startchar] -- needed ?
+        if kerns then
+            local dx, dy, w, h = setpair(start,tfmdata.parameters.factor,rlmode,sequence.flags[4],kerns,characters[startchar])
+            if trace_kerns then
+                logprocess("%s: shifting single %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),dx,dy,w,h)
+            end
+        end
+    end
+    return head, start, false
+end
+
+chainmores.gpos_single = chainprocs.gpos_single -- okay?
+
+-- when machines become faster i will make a shared function
+
+function chainprocs.gpos_pair(head,start,stop,kind,chainname,currentcontext,lookuphash,currentlookup,chainlookupname,chainindex,sequence)
+    local snext = start.next
+    if snext then
+        local startchar = start.char
+        local subtables = currentlookup.subtables
+        local lookupname = subtables[1]
+        local kerns = lookuphash[lookupname]
+        if kerns then
+            kerns = kerns[startchar]
+            if kerns then
+                local lookuptype = lookuptypes[lookupname]
+                local prev, done = start, false
+                local factor = tfmdata.parameters.factor
+                while snext and snext.id == glyph_code and snext.font == currentfont and snext.subtype<256 do
+                    local nextchar = snext.char
+                    local krn = kerns[nextchar]
+                    if not krn and marks[nextchar] then
+                        prev = snext
+                        snext = snext.next
+                    else
+                        if not krn then
+                            -- skip
+                        elseif type(krn) == "table" then
+                            if lookuptype == "pair" then
+                                local a, b = krn[2], krn[3]
+                                if a and #a > 0 then
+                                    local startchar = start.char
+                                    local x, y, w, h = setpair(start,factor,rlmode,sequence.flags[4],a,characters[startchar])
+                                    if trace_kerns then
+                                        logprocess("%s: shifting first of pair %s and %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),gref(nextchar),x,y,w,h)
+                                    end
+                                end
+                                if b and #b > 0 then
+                                    local startchar = start.char
+                                    local x, y, w, h = setpair(snext,factor,rlmode,sequence.flags[4],b,characters[nextchar])
+                                    if trace_kerns then
+                                        logprocess("%s: shifting second of pair %s and %s by (%p,%p) and correction (%p,%p)",cref(kind,chainname,chainlookupname),gref(startchar),gref(nextchar),x,y,w,h)
+                                    end
+                                end
+                            else
+                                report_process("%s: check this out (old kern stuff)",cref(kind,chainname,chainlookupname))
+                                local a, b = krn[2], krn[6]
+                                if a and a ~= 0 then
+                                    local k = setkern(snext,factor,rlmode,a)
+                                    if trace_kerns then
+                                        logprocess("%s: inserting first kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(prev.char),gref(nextchar))
+                                    end
+                                end
+                                if b and b ~= 0 then
+                                    logwarning("%s: ignoring second kern xoff %s",cref(kind,chainname,chainlookupname),b*factor)
+                                end
+                            end
+                            done = true
+                        elseif krn ~= 0 then
+                            local k = setkern(snext,factor,rlmode,krn)
+                            if trace_kerns then
+                                logprocess("%s: inserting kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(prev.char),gref(nextchar))
+                            end
+                            done = true
+                        end
+                        break
+                    end
+                end
+                return head, start, done
+            end
+        end
+    end
+    return head, start, false
+end
+
+chainmores.gpos_pair = chainprocs.gpos_pair -- okay?
+
+-- what pointer to return, spec says stop
+-- to be discussed ... is bidi changer a space?
+-- elseif char == zwnj and sequence[n][32] then -- brrr
+
+-- somehow l or f is global
+-- we don't need to pass the currentcontext, saves a bit
+-- make a slow variant then can be activated but with more tracing
+
+local function show_skip(kind,chainname,char,ck,class)
+    if ck[9] then
+        logwarning("%s: skipping char %s, class %a, rule %a, lookuptype %a, %a => %a",cref(kind,chainname),gref(char),class,ck[1],ck[2],ck[9],ck[10])
+    else
+        logwarning("%s: skipping char %s, class %a, rule %a, lookuptype %a",cref(kind,chainname),gref(char),class,ck[1],ck[2])
+    end
+end
+
+local function normal_handle_contextchain(head,start,kind,chainname,contexts,sequence,lookuphash)
+    --  local rule, lookuptype, sequence, f, l, lookups = ck[1], ck[2] ,ck[3], ck[4], ck[5], ck[6]
+    local flags        = sequence.flags
+    local done         = false
+    local skipmark     = flags[1]
+    local skipligature = flags[2]
+    local skipbase     = flags[3]
+    local someskip     = skipmark or skipligature or skipbase -- could be stored in flags for a fast test (hm, flags could be false !)
+    local markclass    = sequence.markclass                   -- todo, first we need a proper test
+    local skipped      = false
+    for k=1,#contexts do
+        local match   = true
+        local current = start
+        local last    = start
+        local ck      = contexts[k]
+        local seq     = ck[3]
+        local s       = #seq
+        -- f..l = mid string
+        if s == 1 then
+            -- never happens
+            match = current.id == glyph_code and current.font == currentfont and current.subtype<256 and seq[1][current.char]
+        else
+            -- maybe we need a better space check (maybe check for glue or category or combination)
+            -- we cannot optimize for n=2 because there can be disc nodes
+            local f, l = ck[4], ck[5]
+            -- current match
+            if f == 1 and f == l then -- current only
+                -- already a hit
+             -- match = true
+            else -- before/current/after | before/current | current/after
+                -- no need to test first hit (to be optimized)
+                if f == l then -- new, else last out of sync (f is > 1)
+                 -- match = true
+                else
+                    local n = f + 1
+                    last = last.next
+                    while n <= l do
+                        if last then
+                            local id = last.id
+                            if id == glyph_code then
+                                if last.font == currentfont and last.subtype<256 then
+                                    local char = last.char
+                                    local ccd = descriptions[char]
+                                    if ccd then
+                                        local class = ccd.class
+                                        if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+                                            skipped = true
+                                            if trace_skips then
+                                                show_skip(kind,chainname,char,ck,class)
+                                            end
+                                            last = last.next
+                                        elseif seq[n][char] then
+                                            if n < l then
+                                                last = last.next
+                                            end
+                                            n = n + 1
+                                        else
+                                            match = false
+                                            break
+                                        end
+                                    else
+                                        match = false
+                                        break
+                                    end
+                                else
+                                    match = false
+                                    break
+                                end
+                            elseif id == disc_code then
+                                last = last.next
+                            else
+                                match = false
+                                break
+                            end
+                        else
+                            match = false
+                            break
+                        end
+                    end
+                end
+            end
+            -- before
+            if match and f > 1 then
+                local prev = start.prev
+                if prev then
+                    local n = f-1
+                    while n >= 1 do
+                        if prev then
+                            local id = prev.id
+                            if id == glyph_code then
+                                if prev.font == currentfont and prev.subtype<256 then -- normal char
+                                    local char = prev.char
+                                    local ccd = descriptions[char]
+                                    if ccd then
+                                        local class = ccd.class
+                                        if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+                                            skipped = true
+                                            if trace_skips then
+                                                show_skip(kind,chainname,char,ck,class)
+                                            end
+                                        elseif seq[n][char] then
+                                            n = n -1
+                                        else
+                                            match = false
+                                            break
+                                        end
+                                    else
+                                        match = false
+                                        break
+                                    end
+                                else
+                                    match = false
+                                    break
+                                end
+                            elseif id == disc_code then
+                                -- skip 'm
+                            elseif seq[n][32] then
+                                n = n -1
+                            else
+                                match = false
+                                break
+                            end
+                            prev = prev.prev
+                        elseif seq[n][32] then -- somewhat special, as zapfino can have many preceding spaces
+                            n = n -1
+                        else
+                            match = false
+                            break
+                        end
+                    end
+                elseif f == 2 then
+                    match = seq[1][32]
+                else
+                    for n=f-1,1 do
+                        if not seq[n][32] then
+                            match = false
+                            break
+                        end
+                    end
+                end
+            end
+            -- after
+            if match and s > l then
+                local current = last and last.next
+                if current then
+                    -- removed optimization for s-l == 1, we have to deal with marks anyway
+                    local n = l + 1
+                    while n <= s do
+                        if current then
+                            local id = current.id
+                            if id == glyph_code then
+                                if current.font == currentfont and current.subtype<256 then -- normal char
+                                    local char = current.char
+                                    local ccd = descriptions[char]
+                                    if ccd then
+                                        local class = ccd.class
+                                        if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+                                            skipped = true
+                                            if trace_skips then
+                                                show_skip(kind,chainname,char,ck,class)
+                                            end
+                                        elseif seq[n][char] then
+                                            n = n + 1
+                                        else
+                                            match = false
+                                            break
+                                        end
+                                    else
+                                        match = false
+                                        break
+                                    end
+                                else
+                                    match = false
+                                    break
+                                end
+                            elseif id == disc_code then
+                                -- skip 'm
+                            elseif seq[n][32] then -- brrr
+                                n = n + 1
+                            else
+                                match = false
+                                break
+                            end
+                            current = current.next
+                        elseif seq[n][32] then
+                            n = n + 1
+                        else
+                            match = false
+                            break
+                        end
+                    end
+                elseif s-l == 1 then
+                    match = seq[s][32]
+                else
+                    for n=l+1,s do
+                        if not seq[n][32] then
+                            match = false
+                            break
+                        end
+                    end
+                end
+            end
+        end
+        if match then
+            -- ck == currentcontext
+            if trace_contexts then
+                local rule, lookuptype, f, l = ck[1], ck[2], ck[4], ck[5]
+                local char = start.char
+                if ck[9] then
+                    logwarning("%s: rule %s matches at char %s for (%s,%s,%s) chars, lookuptype %a, %a => %a",
+                        cref(kind,chainname),rule,gref(char),f-1,l-f+1,s-l,lookuptype,ck[9],ck[10])
+                else
+                    logwarning("%s: rule %s matches at char %s for (%s,%s,%s) chars, lookuptype %a",
+                        cref(kind,chainname),rule,gref(char),f-1,l-f+1,s-l,lookuptype)
+                end
+            end
+            local chainlookups = ck[6]
+            if chainlookups then
+                local nofchainlookups = #chainlookups
+                -- we can speed this up if needed
+                if nofchainlookups == 1 then
+                    local chainlookupname = chainlookups[1]
+                    local chainlookup = lookuptable[chainlookupname]
+                    if chainlookup then
+                        local cp = chainprocs[chainlookup.type]
+                        if cp then
+                            local ok
+                            head, start, ok = cp(head,start,last,kind,chainname,ck,lookuphash,chainlookup,chainlookupname,nil,sequence)
+                            if ok then
+                                done = true
+                            end
+                        else
+                            logprocess("%s: %s is not yet supported",cref(kind,chainname,chainlookupname),chainlookup.type)
+                        end
+                    else -- shouldn't happen
+                        logprocess("%s is not yet supported",cref(kind,chainname,chainlookupname))
+                    end
+                 else
+                    local i = 1
+                    repeat
+                        if skipped then
+                            while true do
+                                local char = start.char
+                                local ccd = descriptions[char]
+                                if ccd then
+                                    local class = ccd.class
+                                    if class == skipmark or class == skipligature or class == skipbase or (markclass and class == "mark" and not markclass[char]) then
+                                        start = start.next
+                                    else
+                                        break
+                                    end
+                                else
+                                    break
+                                end
+                            end
+                        end
+                        local chainlookupname = chainlookups[i]
+                        local chainlookup = lookuptable[chainlookupname]
+                        if not chainlookup then
+                            -- okay, n matches, < n replacements
+                            i = i + 1
+                        else
+                            local cp = chainmores[chainlookup.type]
+                            if not cp then
+                                -- actually an error
+                                logprocess("%s: %s is not yet supported",cref(kind,chainname,chainlookupname),chainlookup.type)
+                                i = i + 1
+                            else
+                                local ok, n
+                                head, start, ok, n = cp(head,start,last,kind,chainname,ck,lookuphash,chainlookup,chainlookupname,i,sequence)
+                                -- messy since last can be changed !
+                                if ok then
+                                    done = true
+                                    -- skip next one(s) if ligature
+                                    i = i + (n or 1)
+                                else
+                                    i = i + 1
+                                end
+                            end
+                        end
+                        if start then
+                            start = start.next
+                        else
+                            -- weird
+                        end
+                    until i > nofchainlookups
+                end
+            else
+                local replacements = ck[7]
+                if replacements then
+                    head, start, done = chainprocs.reversesub(head,start,last,kind,chainname,ck,lookuphash,replacements) -- sequence
+                else
+                    done = true -- can be meant to be skipped
+                    if trace_contexts then
+                        logprocess("%s: skipping match",cref(kind,chainname))
+                    end
+                end
+            end
+        end
+    end
+    return head, start, done
+end
+
+-- Because we want to keep this elsewhere (an because speed is less an issue) we
+-- pass the font id so that the verbose variant can access the relevant helper tables.
+
+local verbose_handle_contextchain = function(font,...)
+    logwarning("no verbose handler installed, reverting to 'normal'")
+    otf.setcontextchain()
+    return normal_handle_contextchain(...)
+end
+
+otf.chainhandlers = {
+    normal  = normal_handle_contextchain,
+    verbose = verbose_handle_contextchain,
+}
+
+function otf.setcontextchain(method)
+    if not method or method == "normal" or not otf.chainhandlers[method] then
+        if handlers.contextchain then -- no need for a message while making the format
+            logwarning("installing normal contextchain handler")
+        end
+        handlers.contextchain = normal_handle_contextchain
+    else
+        logwarning("installing contextchain handler %a",method)
+        local handler = otf.chainhandlers[method]
+        handlers.contextchain = function(...)
+            return handler(currentfont,...) -- hm, get rid of ...
+        end
+    end
+    handlers.gsub_context             = handlers.contextchain
+    handlers.gsub_contextchain        = handlers.contextchain
+    handlers.gsub_reversecontextchain = handlers.contextchain
+    handlers.gpos_contextchain        = handlers.contextchain
+    handlers.gpos_context             = handlers.contextchain
+end
+
+otf.setcontextchain()
+
+local missing = { } -- we only report once
+
+local function logprocess(...)
+    if trace_steps then
+        registermessage(...)
+    end
+    report_process(...)
+end
+
+local logwarning = report_process
+
+local function report_missing_cache(typ,lookup)
+    local f = missing[currentfont] if not f then f = { } missing[currentfont] = f end
+    local t = f[typ]               if not t then t = { } f[typ]               = t end
+    if not t[lookup] then
+        t[lookup] = true
+        logwarning("missing cache for lookup %a, type %a, font %a, name %a",lookup,typ,currentfont,tfmdata.properties.fullname)
+    end
+end
+
+local resolved = { } -- we only resolve a font,script,language pair once
+
+-- todo: pass all these 'locals' in a table
+
+local lookuphashes = { }
+
+setmetatableindex(lookuphashes, function(t,font)
+    local lookuphash = fontdata[font].resources.lookuphash
+    if not lookuphash or not next(lookuphash) then
+        lookuphash = false
+    end
+    t[font] = lookuphash
+    return lookuphash
+end)
+
+-- fonts.hashes.lookups = lookuphashes
+
+local autofeatures = fonts.analyzers.features -- was: constants
+
+local function initialize(sequence,script,language,enabled)
+    local features = sequence.features
+    if features then
+        for kind, scripts in next, features do
+            local valid = enabled[kind]
+            if valid then
+                local languages = scripts[script] or scripts[wildcard]
+                if languages and (languages[language] or languages[wildcard]) then
+                    return { valid, autofeatures[kind] or false, sequence.chain or 0, kind, sequence }
+                end
+            end
+        end
+    end
+    return false
+end
+
+function otf.dataset(tfmdata,font) -- generic variant, overloaded in context
+    local shared     = tfmdata.shared
+    local properties = tfmdata.properties
+    local language   = properties.language or "dflt"
+    local script     = properties.script   or "dflt"
+    local enabled    = shared.features
+    local res = resolved[font]
+    if not res then
+        res = { }
+        resolved[font] = res
+    end
+    local rs = res[script]
+    if not rs then
+        rs = { }
+        res[script] = rs
+    end
+    local rl = rs[language]
+    if not rl then
+        rl = {
+            -- indexed but we can also add specific data by key
+        }
+        rs[language] = rl
+        local sequences = tfmdata.resources.sequences
+--         setmetatableindex(rl, function(t,k)
+--             if type(k) == "number" then
+--                 local v = enabled and initialize(sequences[k],script,language,enabled)
+--                 t[k] = v
+--                 return v
+--             end
+--         end)
+for s=1,#sequences do
+    local v = enabled and initialize(sequences[s],script,language,enabled)
+    if v then
+        rl[#rl+1] = v
+    end
+end
+    end
+    return rl
+end
+
+-- elseif id == glue_code then
+--     if p[5] then -- chain
+--         local pc = pp[32]
+--         if pc then
+--             start, ok = start, false -- p[1](start,kind,p[2],pc,p[3],p[4])
+--             if ok then
+--                 done = true
+--             end
+--             if start then start = start.next end
+--         else
+--             start = start.next
+--         end
+--     else
+--         start = start.next
+--     end
+
+-- there will be a new direction parser (pre-parsed etc)
+
+-- less bytecode: 290 -> 254
+--
+-- attr = attr or false
+--
+-- local a = getattr(start,0)
+-- if (a == attr and (not attribute or getattr(start,a_state) == attribute)) or (not attribute or getattr(start,a_state) == attribute) then
+--     -- the action
+-- end
+
+local function featuresprocessor(head,font,attr)
+
+    local lookuphash = lookuphashes[font] -- we can also check sequences here
+
+    if not lookuphash then
+        return head, false
+    end
+
+    if trace_steps then
+        checkstep(head)
+    end
+
+    tfmdata         = fontdata[font]
+    descriptions    = tfmdata.descriptions
+    characters      = tfmdata.characters
+    resources       = tfmdata.resources
+
+    marks           = resources.marks
+    anchorlookups   = resources.lookup_to_anchor
+    lookuptable     = resources.lookups
+    lookuptypes     = resources.lookuptypes
+
+    currentfont     = font
+    rlmode          = 0
+
+    local sequences = resources.sequences
+    local done      = false
+    local datasets  = otf.dataset(tfmdata,font,attr)
+
+    local dirstack  = { } -- could move outside function
+
+    -- We could work on sub start-stop ranges instead but I wonder if there is that
+    -- much speed gain (experiments showed that it made not much sense) and we need
+    -- to keep track of directions anyway. Also at some point I want to play with
+    -- font interactions and then we do need the full sweeps.
+
+    -- Keeping track of the headnode is needed for devanagari (I generalized it a bit
+    -- so that multiple cases are also covered.)
+
+    for s=1,#datasets do
+        local dataset = datasets[s]
+        featurevalue = dataset[1] -- todo: pass to function instead of using a global
+
+        local sequence  = dataset[5] -- sequences[s] -- also dataset[5]
+        local rlparmode = 0
+        local topstack  = 0
+        local success   = false
+        local attribute = dataset[2]
+        local chain     = dataset[3] -- sequence.chain or 0
+        local typ       = sequence.type
+        local subtables = sequence.subtables
+        if chain < 0 then
+            -- this is a limited case, no special treatments like 'init' etc
+            local handler = handlers[typ]
+            -- we need to get rid of this slide! probably no longer needed in latest luatex
+            local start = find_node_tail(head) -- slow (we can store tail because there's always a skip at the end): todo
+            while start do
+                local id = start.id
+                if id == glyph_code then
+                    if start.font == font and start.subtype<256 then
+                        local a = start[0]
+                        if a then
+                            a = a == attr
+                        else
+                            a = true
+                        end
+                        if a then
+                            for i=1,#subtables do
+                                local lookupname = subtables[i]
+                                local lookupcache = lookuphash[lookupname]
+                                if lookupcache then
+                                    local lookupmatch = lookupcache[start.char]
+                                    if lookupmatch then
+                                        head, start, success = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+                                        if success then
+                                            break
+                                        end
+                                    end
+                                else
+                                    report_missing_cache(typ,lookupname)
+                                end
+                            end
+                            if start then start = start.prev end
+                        else
+                            start = start.prev
+                        end
+                    else
+                        start = start.prev
+                    end
+                else
+                    start = start.prev
+                end
+            end
+        else
+            local handler = handlers[typ]
+            local ns = #subtables
+            local start = head -- local ?
+            rlmode = 0 -- to be checked ?
+            if ns == 1 then -- happens often
+                local lookupname = subtables[1]
+                local lookupcache = lookuphash[lookupname]
+                if not lookupcache then -- also check for empty cache
+                    report_missing_cache(typ,lookupname)
+                else
+
+                    local function subrun(start)
+                        -- mostly for gsub, gpos would demand a more clever approach
+                        local head = start
+                        local done = false
+                        while start do
+                            local id = start.id
+                            if id == glyph_code and start.font == font and start.subtype <256 then
+                                local a = start[0]
+                                if a then
+                                    a = (a == attr) and (not attribute or start[a_state] == attribute)
+                                else
+                                    a = not attribute or start[a_state] == attribute
+                                end
+                                if a then
+                                    local lookupmatch = lookupcache[start.char]
+                                    if lookupmatch then
+                                        -- sequence kan weg
+                                        local ok
+                                        head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
+                                        if ok then
+                                            done = true
+                                        end
+                                    end
+                                    if start then start = start.next end
+                                else
+                                    start = start.next
+                                end
+                            else
+                                start = start.next
+                            end
+                        end
+                        if done then
+                            success = true
+                            return head
+                        end
+                    end
+
+                    local function kerndisc(disc) -- we can assume that prev and next are glyphs
+                        local prev = disc.prev
+                        local next = disc.next
+                        if prev and next then
+                            prev.next = next
+                         -- next.prev = prev
+                            local a = prev[0]
+                            if a then
+                                a = (a == attr) and (not attribute or prev[a_state] == attribute)
+                            else
+                                a = not attribute or prev[a_state] == attribute
+                            end
+                            if a then
+                                local lookupmatch = lookupcache[prev.char]
+                                if lookupmatch then
+                                    -- sequence kan weg
+                                    local h, d, ok = handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
+                                    if ok then
+                                        done = true
+                                        success = true
+                                    end
+                                end
+                            end
+                            prev.next = disc
+                         -- next.prev = disc
+                        end
+                        return next
+                    end
+
+                    while start do
+                        local id = start.id
+                        if id == glyph_code then
+                            if start.font == font and start.subtype<256 then
+                                local a = start[0]
+                                if a then
+                                    a = (a == attr) and (not attribute or start[a_state] == attribute)
+                                else
+                                    a = not attribute or start[a_state] == attribute
+                                end
+                                if a then
+                                    local lookupmatch = lookupcache[start.char]
+                                    if lookupmatch then
+                                        -- sequence kan weg
+                                        local ok
+                                        head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
+                                        if ok then
+                                            success = true
+                                        end
+                                    end
+                                    if start then start = start.next end
+                                else
+                                    start = start.next
+                                end
+                            else
+                                start = start.next
+                            end
+                        elseif id == disc_code then
+                            -- mostly for gsub
+                            if start.subtype == discretionary_code then
+                                local pre = start.pre
+                                if pre then
+                                    local new = subrun(pre)
+                                    if new then start.pre = new end
+                                end
+                                local post = start.post
+                                if post then
+                                    local new = subrun(post)
+                                    if new then start.post = new end
+                                end
+                                local replace = start.replace
+                                if replace then
+                                    local new = subrun(replace)
+                                    if new then start.replace = new end
+                                end
+elseif typ == "gpos_single" or typ == "gpos_pair" then
+    kerndisc(start)
+                            end
+                            start = start.next
+                        elseif id == whatsit_code then -- will be function
+                            local subtype = start.subtype
+                            if subtype == dir_code then
+                                local dir = start.dir
+                                if     dir == "+TRT" or dir == "+TLT" then
+                                    topstack = topstack + 1
+                                    dirstack[topstack] = dir
+                                elseif dir == "-TRT" or dir == "-TLT" then
+                                    topstack = topstack - 1
+                                end
+                                local newdir = dirstack[topstack]
+                                if newdir == "+TRT" then
+                                    rlmode = -1
+                                elseif newdir == "+TLT" then
+                                    rlmode = 1
+                                else
+                                    rlmode = rlparmode
+                                end
+                                if trace_directions then
+                                    report_process("directions after txtdir %a: parmode %a, txtmode %a, # stack %a, new dir %a",dir,rlparmode,rlmode,topstack,newdir)
+                                end
+                            elseif subtype == localpar_code then
+                                local dir = start.dir
+                                if dir == "TRT" then
+                                    rlparmode = -1
+                                elseif dir == "TLT" then
+                                    rlparmode = 1
+                                else
+                                    rlparmode = 0
+                                end
+                                -- one might wonder if the par dir should be looked at, so we might as well drop the next line
+                                rlmode = rlparmode
+                                if trace_directions then
+                                    report_process("directions after pardir %a: parmode %a, txtmode %a",dir,rlparmode,rlmode)
+                                end
+                            end
+                            start = start.next
+                        elseif id == math_code then
+                            start = end_of_math(start).next
+                        else
+                            start = start.next
+                        end
+                    end
+                end
+            else
+
+                local function subrun(start)
+                    -- mostly for gsub, gpos would demand a more clever approach
+                    local head = start
+                    local done = false
+                    while start do
+                        local id = start.id
+                        if id == glyph_code and start.id == font and start.subtype <256 then
+                            local a = start[0]
+                            if a then
+                                a = (a == attr) and (not attribute or start[a_state] == attribute)
+                            else
+                                a = not attribute or start[a_state] == attribute
+                            end
+                            if a then
+                                for i=1,ns do
+                                    local lookupname = subtables[i]
+                                    local lookupcache = lookuphash[lookupname]
+                                    if lookupcache then
+                                        local lookupmatch = lookupcache[start.char]
+                                        if lookupmatch then
+                                            -- we could move all code inline but that makes things even more unreadable
+                                            local ok
+                                            head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+                                            if ok then
+                                                done = true
+                                                break
+                                            elseif not start then
+                                                -- don't ask why ... shouldn't happen
+                                                break
+                                            end
+                                        end
+                                    else
+                                        report_missing_cache(typ,lookupname)
+                                    end
+                                end
+                                if start then start = start.next end
+                            else
+                                start = start.next
+                            end
+                        else
+                            start = start.next
+                        end
+                    end
+                    if done then
+                        success = true
+                        return head
+                    end
+                end
+
+                local function kerndisc(disc) -- we can assume that prev and next are glyphs
+                    local prev = disc.prev
+                    local next = disc.next
+                    if prev and next then
+                        prev.next = next
+                     -- next.prev = prev
+                        local a = prev[0]
+                        if a then
+                            a = (a == attr) and (not attribute or prev[a_state] == attribute)
+                        else
+                            a = not attribute or prev[a_state] == attribute
+                        end
+                        if a then
+                            for i=1,ns do
+                                local lookupname = subtables[i]
+                                local lookupcache = lookuphash[lookupname]
+                                if lookupcache then
+                                    local lookupmatch = lookupcache[prev.char]
+                                    if lookupmatch then
+                                        -- we could move all code inline but that makes things even more unreadable
+                                        local h, d, ok = handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+                                        if ok then
+                                            done = true
+                                            break
+                                        end
+                                    end
+                                else
+                                    report_missing_cache(typ,lookupname)
+                                end
+                            end
+                        end
+                        prev.next = disc
+                     -- next.prev = disc
+                    end
+                    return next
+                end
+
+                while start do
+                    local id = start.id
+                    if id == glyph_code then
+                        if start.font == font and start.subtype<256 then
+                            local a = start[0]
+                            if a then
+                                a = (a == attr) and (not attribute or start[a_state] == attribute)
+                            else
+                                a = not attribute or start[a_state] == attribute
+                            end
+                            if a then
+                                for i=1,ns do
+                                    local lookupname = subtables[i]
+                                    local lookupcache = lookuphash[lookupname]
+                                    if lookupcache then
+                                        local lookupmatch = lookupcache[start.char]
+                                        if lookupmatch then
+                                            -- we could move all code inline but that makes things even more unreadable
+                                            local ok
+                                            head, start, ok = handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
+                                            if ok then
+                                                success = true
+                                                break
+                                            elseif not start then
+                                                -- don't ask why ... shouldn't happen
+                                                break
+                                            end
+                                        end
+                                    else
+                                        report_missing_cache(typ,lookupname)
+                                    end
+                                end
+                                if start then start = start.next end
+                            else
+                                start = start.next
+                            end
+                        else
+                            start = start.next
+                        end
+                    elseif id == disc_code then
+                        -- mostly for gsub
+                        if start.subtype == discretionary_code then
+                            local pre = start.pre
+                            if pre then
+                                local new = subrun(pre)
+                                if new then start.pre = new end
+                            end
+                            local post = start.post
+                            if post then
+                                local new = subrun(post)
+                                if new then start.post = new end
+                            end
+                            local replace = start.replace
+                            if replace then
+                                local new = subrun(replace)
+                                if new then start.replace = new end
+                            end
+elseif typ == "gpos_single" or typ == "gpos_pair" then
+    kerndisc(start)
+                        end
+                        start = start.next
+                    elseif id == whatsit_code then
+                        local subtype = start.subtype
+                        if subtype == dir_code then
+                            local dir = start.dir
+                            if     dir == "+TRT" or dir == "+TLT" then
+                                topstack = topstack + 1
+                                dirstack[topstack] = dir
+                            elseif dir == "-TRT" or dir == "-TLT" then
+                                topstack = topstack - 1
+                            end
+                            local newdir = dirstack[topstack]
+                            if newdir == "+TRT" then
+                                rlmode = -1
+                            elseif newdir == "+TLT" then
+                                rlmode = 1
+                            else
+                                rlmode = rlparmode
+                            end
+                            if trace_directions then
+                                report_process("directions after txtdir %a: parmode %a, txtmode %a, # stack %a, new dir %a",dir,rlparmode,rlmode,topstack,newdir)
+                            end
+                        elseif subtype == localpar_code then
+                            local dir = start.dir
+                            if dir == "TRT" then
+                                rlparmode = -1
+                            elseif dir == "TLT" then
+                                rlparmode = 1
+                            else
+                                rlparmode = 0
+                            end
+                            rlmode = rlparmode
+                            if trace_directions then
+                                report_process("directions after pardir %a: parmode %a, txtmode %a",dir,rlparmode,rlmode)
+                            end
+                        end
+                        start = start.next
+                    elseif id == math_code then
+                        start = end_of_math(start).next
+                    else
+                        start = start.next
+                    end
+                end
+            end
+        end
+        if success then
+            done = true
+        end
+        if trace_steps then -- ?
+            registerstep(head)
+        end
+    end
+    return head, done
+end
+
+local function generic(lookupdata,lookupname,unicode,lookuphash)
+    local target = lookuphash[lookupname]
+    if target then
+        target[unicode] = lookupdata
+    else
+        lookuphash[lookupname] = { [unicode] = lookupdata }
+    end
+end
+
+local action = {
+
+    substitution = generic,
+    multiple     = generic,
+    alternate    = generic,
+    position     = generic,
+
+    ligature = function(lookupdata,lookupname,unicode,lookuphash)
+        local target = lookuphash[lookupname]
+        if not target then
+            target = { }
+            lookuphash[lookupname] = target
+        end
+        for i=1,#lookupdata do
+            local li = lookupdata[i]
+            local tu = target[li]
+            if not tu then
+                tu = { }
+                target[li] = tu
+            end
+            target = tu
+        end
+        target.ligature = unicode
+    end,
+
+    pair = function(lookupdata,lookupname,unicode,lookuphash)
+        local target = lookuphash[lookupname]
+        if not target then
+            target = { }
+            lookuphash[lookupname] = target
+        end
+        local others = target[unicode]
+        local paired = lookupdata[1]
+        if others then
+            others[paired] = lookupdata
+        else
+            others = { [paired] = lookupdata }
+            target[unicode] = others
+        end
+    end,
+
+}
+
+local function prepare_lookups(tfmdata)
+
+    local rawdata          = tfmdata.shared.rawdata
+    local resources        = rawdata.resources
+    local lookuphash       = resources.lookuphash
+    local anchor_to_lookup = resources.anchor_to_lookup
+    local lookup_to_anchor = resources.lookup_to_anchor
+    local lookuptypes      = resources.lookuptypes
+    local characters       = tfmdata.characters
+    local descriptions     = tfmdata.descriptions
+
+    -- we cannot free the entries in the descriptions as sometimes we access
+    -- then directly (for instance anchors) ... selectively freeing does save
+    -- much memory as it's only a reference to a table and the slot in the
+    -- description hash is not freed anyway
+
+    for unicode, character in next, characters do -- we cannot loop over descriptions !
+
+        local description = descriptions[unicode]
+
+        if description then
+
+            local lookups = description.slookups
+            if lookups then
+                for lookupname, lookupdata in next, lookups do
+                    action[lookuptypes[lookupname]](lookupdata,lookupname,unicode,lookuphash)
+                end
+            end
+
+            local lookups = description.mlookups
+            if lookups then
+                for lookupname, lookuplist in next, lookups do
+                    local lookuptype = lookuptypes[lookupname]
+                    for l=1,#lookuplist do
+                        local lookupdata = lookuplist[l]
+                        action[lookuptype](lookupdata,lookupname,unicode,lookuphash)
+                    end
+                end
+            end
+
+            local list = description.kerns
+            if list then
+                for lookup, krn in next, list do  -- ref to glyph, saves lookup
+                    local target = lookuphash[lookup]
+                    if target then
+                        target[unicode] = krn
+                    else
+                        lookuphash[lookup] = { [unicode] = krn }
+                    end
+                end
+            end
+
+            local list = description.anchors
+            if list then
+                for typ, anchors in next, list do -- types
+                    if typ == "mark" or typ == "cexit" then -- or entry?
+                        for name, anchor in next, anchors do
+                            local lookups = anchor_to_lookup[name]
+                            if lookups then
+                                for lookup, _ in next, lookups do
+                                    local target = lookuphash[lookup]
+                                    if target then
+                                        target[unicode] = anchors
+                                    else
+                                        lookuphash[lookup] = { [unicode] = anchors }
+                                    end
+                                end
+                            end
+                        end
+                    end
+                end
+            end
+
+        end
+
+    end
+
+end
+
+local function split(replacement,original)
+    local result = { }
+    for i=1,#replacement do
+        result[original[i]] = replacement[i]
+    end
+    return result
+end
+
+local valid = {
+    coverage        = { chainsub = true, chainpos = true, contextsub = true },
+    reversecoverage = { reversesub = true },
+    glyphs          = { chainsub = true, chainpos = true },
+}
+
+local function prepare_contextchains(tfmdata)
+    local rawdata    = tfmdata.shared.rawdata
+    local resources  = rawdata.resources
+    local lookuphash = resources.lookuphash
+    local lookups    = rawdata.lookups
+    if lookups then
+        for lookupname, lookupdata in next, rawdata.lookups do
+            local lookuptype = lookupdata.type
+            if lookuptype then
+                local rules = lookupdata.rules
+                if rules then
+                    local format = lookupdata.format
+                    local validformat = valid[format]
+                    if not validformat then
+                        report_prepare("unsupported format %a",format)
+                    elseif not validformat[lookuptype] then
+                        -- todo: dejavu-serif has one (but i need to see what use it has)
+                        report_prepare("unsupported format %a, lookuptype %a, lookupname %a",format,lookuptype,lookupname)
+                    else
+                        local contexts = lookuphash[lookupname]
+                        if not contexts then
+                            contexts = { }
+                            lookuphash[lookupname] = contexts
+                        end
+                        local t, nt = { }, 0
+                        for nofrules=1,#rules do
+                            local rule         = rules[nofrules]
+                            local current      = rule.current
+                            local before       = rule.before
+                            local after        = rule.after
+                            local replacements = rule.replacements
+                            local sequence     = { }
+                            local nofsequences = 0
+                            -- Eventually we can store start, stop and sequence in the cached file
+                            -- but then less sharing takes place so best not do that without a lot
+                            -- of profiling so let's forget about it.
+                            if before then
+                                for n=1,#before do
+                                    nofsequences = nofsequences + 1
+                                    sequence[nofsequences] = before[n]
+                                end
+                            end
+                            local start = nofsequences + 1
+                            for n=1,#current do
+                                nofsequences = nofsequences + 1
+                                sequence[nofsequences] = current[n]
+                            end
+                            local stop = nofsequences
+                            if after then
+                                for n=1,#after do
+                                    nofsequences = nofsequences + 1
+                                    sequence[nofsequences] = after[n]
+                                end
+                            end
+                            if sequence[1] then
+                                -- Replacements only happen with reverse lookups as they are single only. We
+                                -- could pack them into current (replacement value instead of true) and then
+                                -- use sequence[start] instead but it's somewhat ugly.
+                                nt = nt + 1
+                                t[nt] = { nofrules, lookuptype, sequence, start, stop, rule.lookups, replacements }
+                                for unic, _  in next, sequence[start] do
+                                    local cu = contexts[unic]
+                                    if not cu then
+                                        contexts[unic] = t
+                                    end
+                                end
+                            end
+                        end
+                    end
+                else
+                    -- no rules
+                end
+            else
+                report_prepare("missing lookuptype for lookupname %a",lookupname)
+            end
+        end
+    end
+end
+
+-- we can consider lookuphash == false (initialized but empty) vs lookuphash == table
+
+local function featuresinitializer(tfmdata,value)
+    if true then -- value then
+        -- beware we need to use the topmost properties table
+        local rawdata    = tfmdata.shared.rawdata
+        local properties = rawdata.properties
+        if not properties.initialized then
+            local starttime = trace_preparing and os.clock()
+            local resources = rawdata.resources
+            resources.lookuphash = resources.lookuphash or { }
+            prepare_contextchains(tfmdata)
+            prepare_lookups(tfmdata)
+            properties.initialized = true
+            if trace_preparing then
+                report_prepare("preparation time is %0.3f seconds for %a",os.clock()-starttime,tfmdata.properties.fullname)
+            end
+        end
+    end
+end
+
+registerotffeature {
+    name         = "features",
+    description  = "features",
+    default      = true,
+    initializers = {
+        position = 1,
+        node     = featuresinitializer,
+    },
+    processors   = {
+        node     = featuresprocessor,
+    }
+}
+
+-- This can be used for extra handlers, but should be used with care!
+
+otf.handlers = handlers
diff --git a/luaotfload.dtx b/luaotfload.dtx
index f450d61..6f8ebc4 100644
--- a/luaotfload.dtx
+++ b/luaotfload.dtx
@@ -1199,6 +1199,8 @@ and the derived files
 %                     \incitem{luatex-fonts-tfm.lua}
 %                     \incitem{luatex-fonts-chr.lua}
 %                     \incitem{luatex-fonts-lua.lua}
+%                     \incitem{luatex-fonts-inj.lua}
+%                     \incitem{luatex-fonts-otn.lua}
 %                     \incitem{luatex-fonts-def.lua}
 %                     \incitem{luatex-fonts-ext.lua}
 %                     \incitem{luatex-fonts-cbk.lua}
@@ -1214,8 +1216,7 @@ and the derived files
 %                     \incitem{font-con.lua} \incitem{font-cid.lua}
 %                     \incitem{font-map.lua} \incitem{font-oti.lua}
 %                     \incitem{font-otf.lua} \incitem{font-otb.lua}
-%                     \incitem{node-inj.lua} \incitem{font-ota.lua}
-%                     \incitem{font-otn.lua} \incitem{font-def.lua}
+%                     \incitem{font-ota.lua} \incitem{font-def.lua}
 %                     \incitem{font-otp.lua}
 %                   \end{itemize}
 %                 \end{multicols}
@@ -1594,7 +1595,6 @@ config.luaotfload                 = config.luaotfload or { }
 ------.luaotfload.resolver        = config.luaotfload.resolver         or "normal"
 config.luaotfload.resolver        = config.luaotfload.resolver         or "cached"
 config.luaotfload.definer         = config.luaotfload.definer          or "patch"
-config.luaotfload.compatibility   = config.luaotfload.compatibility    or false
 config.luaotfload.loglevel        = config.luaotfload.loglevel         or 2
 config.luaotfload.color_callback  = config.luaotfload.color_callback   or "pre_linebreak_filter"
 config.luaotfload.prioritize      = config.luaotfload.prioritize       or "sys"
@@ -1879,10 +1879,10 @@ else--- the loading sequence is known to change, so this might have to
     loadmodule('font-oti.lua')
     loadmodule('font-otf.lua')
     loadmodule('font-otb.lua')
-    loadmodule('node-inj.lua')
+    loadmodule('luatex-fonts-inj.lua')  --> since 2014-01-07, replaces node-inj.lua
     loadmodule('font-ota.lua')
-    loadmodule('font-otn.lua')
-    loadmodule('font-otp.lua')--- since 2013-04-23
+    loadmodule('luatex-fonts-otn.lua')  --> since 2014-01-07, replaces font-otn.lua
+    loadmodule('font-otp.lua')          --> since 2013-04-23
     loadmodule('luatex-fonts-lua.lua')
     loadmodule('font-def.lua')
     loadmodule('luatex-fonts-def.lua')