2014-01-03 00:42:00

1 files changed, 505 insertions, 564 deletions

diff --git a/tex/generic/context/luatex/luatex-fonts-merged.lua b/tex/generic/context/luatex/luatex-fonts-merged.lua
index 3f408b96f..24e49308c 100644
--- a/tex/generic/context/luatex/luatex-fonts-merged.lua
+++ b/tex/generic/context/luatex/luatex-fonts-merged.lua
@@ -1,6 +1,6 @@
 -- merged file : luatex-fonts-merged.lua
 -- parent file : luatex-fonts.lua
--- merge date  : 02/14/14 17:07:59
+-- merge date  : 01/03/14 00:40:35
 
 do -- begin closure to overcome local limits and interference
 
@@ -82,9 +82,6 @@ function optionalrequire(...)
     return result
   end
 end
-if lua then
-  lua.mask=load([[τεχ = 1]]) and "utf" or "ascii"
-end
 
 end -- closure
 
@@ -104,9 +101,7 @@ local byte,char,gmatch,format=string.byte,string.char,string.gmatch,string.forma
 local floor=math.floor
 local P,R,S,V,Ct,C,Cs,Cc,Cp,Cmt=lpeg.P,lpeg.R,lpeg.S,lpeg.V,lpeg.Ct,lpeg.C,lpeg.Cs,lpeg.Cc,lpeg.Cp,lpeg.Cmt
 local lpegtype,lpegmatch,lpegprint=lpeg.type,lpeg.match,lpeg.print
-if setinspector then
-  setinspector(function(v) if lpegtype(v) then lpegprint(v) return true end end)
-end
+setinspector(function(v) if lpegtype(v) then lpegprint(v) return true end end)
 lpeg.patterns=lpeg.patterns or {} 
 local patterns=lpeg.patterns
 local anything=P(1)
@@ -175,11 +170,9 @@ patterns.spacer=spacer
 patterns.whitespace=whitespace
 patterns.nonspacer=nonspacer
 patterns.nonwhitespace=nonwhitespace
-local stripper=spacer^0*C((spacer^0*nonspacer^1)^0)   
-local fullstripper=whitespace^0*C((whitespace^0*nonwhitespace^1)^0)
+local stripper=spacer^0*C((spacer^0*nonspacer^1)^0)
 local collapser=Cs(spacer^0/""*nonspacer^0*((spacer^0/" "*nonspacer^1)^0))
 patterns.stripper=stripper
-patterns.fullstripper=fullstripper
 patterns.collapser=collapser
 patterns.lowercase=lowercase
 patterns.uppercase=uppercase
@@ -402,7 +395,7 @@ function lpeg.replacer(one,two,makefunction,isutf)
     return pattern
   end
 end
-function lpeg.finder(lst,makefunction,isutf) 
+function lpeg.finder(lst,makefunction) 
   local pattern
   if type(lst)=="table" then
     pattern=P(false)
@@ -418,11 +411,7 @@ function lpeg.finder(lst,makefunction,isutf)
   else
     pattern=P(lst)
   end
-  if isutf then
-    pattern=((utf8char or 1)-pattern)^0*pattern
-  else
-    pattern=(1-pattern)^0*pattern
-  end
+  pattern=(1-pattern)^0*pattern
   if makefunction then
     return function(str)
       return lpegmatch(pattern,str)
@@ -759,15 +748,11 @@ function string.limit(str,n,sentinel)
   end
 end
 local stripper=patterns.stripper
-local fullstripper=patterns.fullstripper
 local collapser=patterns.collapser
 local longtostring=patterns.longtostring
 function string.strip(str)
   return lpegmatch(stripper,str) or ""
 end
-function string.fullstrip(str)
-  return lpegmatch(fullstripper,str) or ""
-end
 function string.collapsespaces(str)
   return lpegmatch(collapser,str) or ""
 end
@@ -1651,9 +1636,7 @@ function table.print(t,...)
     serialize(print,t,...)
   end
 end
-if setinspector then
-  setinspector(function(v) if type(v)=="table" then serialize(print,v,"table") return true end end)
-end
+setinspector(function(v) if type(v)=="table" then serialize(print,v,"table") return true end end)
 function table.sub(t,i,j)
   return { unpack(t,i,j) }
 end
@@ -2525,19 +2508,8 @@ local unpack,concat=table.unpack,table.concat
 local P,V,C,S,R,Ct,Cs,Cp,Carg,Cc=lpeg.P,lpeg.V,lpeg.C,lpeg.S,lpeg.R,lpeg.Ct,lpeg.Cs,lpeg.Cp,lpeg.Carg,lpeg.Cc
 local patterns,lpegmatch=lpeg.patterns,lpeg.match
 local utfchar,utfbyte=utf.char,utf.byte
-local loadstripped=nil
-if _LUAVERSION<5.2 then
-  loadstripped=function(str,shortcuts)
-    return load(str)
-  end
-else
-  loadstripped=function(str,shortcuts)
-    if shortcuts then
-      return load(dump(load(str),true),nil,nil,shortcuts)
-    else
-      return load(dump(load(str),true))
-    end
-  end
+local loadstripped=_LUAVERSION<5.2 and load or function(str)
+  return load(dump(load(str),true)) 
 end
 if not number then number={} end 
 local stripper=patterns.stripzeros
@@ -2687,58 +2659,31 @@ function number.sparseexponent(f,n)
   end
   return tostring(n)
 end
+local preamble=[[
+local type = type
+local tostring = tostring
+local tonumber = tonumber
+local format = string.format
+local concat = table.concat
+local signed = number.signed
+local points = number.points
+local basepoints = number.basepoints
+local utfchar = utf.char
+local utfbyte = utf.byte
+local lpegmatch = lpeg.match
+local nspaces = string.nspaces
+local tracedchar = string.tracedchar
+local autosingle = string.autosingle
+local autodouble = string.autodouble
+local sequenced = table.sequenced
+local formattednumber = number.formatted
+local sparseexponent = number.sparseexponent
+]]
 local template=[[
 %s
 %s
 return function(%s) return %s end
 ]]
-local preamble,environment="",{}
-if _LUAVERSION<5.2 then
-  preamble=[[
-local lpeg=lpeg
-local type=type
-local tostring=tostring
-local tonumber=tonumber
-local format=string.format
-local concat=table.concat
-local signed=number.signed
-local points=number.points
-local basepoints= number.basepoints
-local utfchar=utf.char
-local utfbyte=utf.byte
-local lpegmatch=lpeg.match
-local nspaces=string.nspaces
-local tracedchar=string.tracedchar
-local autosingle=string.autosingle
-local autodouble=string.autodouble
-local sequenced=table.sequenced
-local formattednumber=number.formatted
-local sparseexponent=number.sparseexponent
-    ]]
-else
-  environment={
-    global=global or _G,
-    lpeg=lpeg,
-    type=type,
-    tostring=tostring,
-    tonumber=tonumber,
-    format=string.format,
-    concat=table.concat,
-    signed=number.signed,
-    points=number.points,
-    basepoints=number.basepoints,
-    utfchar=utf.char,
-    utfbyte=utf.byte,
-    lpegmatch=lpeg.match,
-    nspaces=string.nspaces,
-    tracedchar=string.tracedchar,
-    autosingle=string.autosingle,
-    autodouble=string.autodouble,
-    sequenced=table.sequenced,
-    formattednumber=number.formatted,
-    sparseexponent=number.sparseexponent,
-  }
-end
 local arguments={ "a1" } 
 setmetatable(arguments,{ __index=function(t,k)
     local v=t[k-1]..",a"..k
@@ -3060,8 +3005,8 @@ local builder=Cs { "start",
   ["!"]=Carg(2)*prefix_any*P("!")*C((1-P("!"))^1)*P("!")/format_extension,
 }
 local direct=Cs (
-  P("%")*(S("+- .")+R("09"))^0*S("sqidfgGeExXo")*P(-1)/[[local format = string.format return function(str) return format("%0",str) end]]
-)
+    P("%")/""*Cc([[local format = string.format return function(str) return format("%]])*(S("+- .")+R("09"))^0*S("sqidfgGeExXo")*Cc([[",str) end]])*P(-1)
+  )
 local function make(t,str)
   local f
   local p
@@ -3073,7 +3018,7 @@ local function make(t,str)
     p=lpegmatch(builder,str,1,"..",t._extensions_) 
     if n>0 then
       p=format(template,preamble,t._preamble_,arguments[n],p)
-      f=loadstripped(p,t._environment_)() 
+      f=loadstripped(p)()
     else
       f=function() return str end
     end
@@ -3085,22 +3030,10 @@ local function use(t,fmt,...)
   return t[fmt](...)
 end
 strings.formatters={}
-if _LUAVERSION<5.2 then
-  function strings.formatters.new()
-    local t={ _extensions_={},_preamble_=preamble,_environment_={},_type_="formatter" }
-    setmetatable(t,{ __index=make,__call=use })
-    return t
-  end
-else
-  function strings.formatters.new()
-    local e={} 
-    for k,v in next,environment do
-      e[k]=v
-    end
-    local t={ _extensions_={},_preamble_="",_environment_=e,_type_="formatter" }
-    setmetatable(t,{ __index=make,__call=use })
-    return t
-  end
+function strings.formatters.new()
+  local t={ _extensions_={},_preamble_="",_type_="formatter" }
+  setmetatable(t,{ __index=make,__call=use })
+  return t
 end
 local formatters=strings.formatters.new() 
 string.formatters=formatters 
@@ -3108,12 +3041,8 @@ string.formatter=function(str,...) return formatters[str](...) end
 local function add(t,name,template,preamble)
   if type(t)=="table" and t._type_=="formatter" then
     t._extensions_[name]=template or "%s"
-    if type(preamble)=="string" then
+    if preamble then
       t._preamble_=preamble.."\n"..t._preamble_ 
-    elseif type(preamble)=="table" then
-      for k,v in next,preamble do
-        t._environment_[k]=v
-      end
     end
   end
 end
@@ -3122,15 +3051,9 @@ patterns.xmlescape=Cs((P("<")/"&lt;"+P(">")/"&gt;"+P("&")/"&amp;"+P('"')/"&quot;
 patterns.texescape=Cs((C(S("#$%\\{}"))/"\\%1"+P(1))^0)
 patterns.luaescape=Cs(((1-S('"\n'))^1+P('"')/'\\"'+P('\n')/'\\n"')^0) 
 patterns.luaquoted=Cs(Cc('"')*((1-S('"\n'))^1+P('"')/'\\"'+P('\n')/'\\n"')^0*Cc('"'))
-if _LUAVERSION<5.2 then
-  add(formatters,"xml",[[lpegmatch(xmlescape,%s)]],"local xmlescape = lpeg.patterns.xmlescape")
-  add(formatters,"tex",[[lpegmatch(texescape,%s)]],"local texescape = lpeg.patterns.texescape")
-  add(formatters,"lua",[[lpegmatch(luaescape,%s)]],"local luaescape = lpeg.patterns.luaescape")
-else
-  add(formatters,"xml",[[lpegmatch(xmlescape,%s)]],{ xmlescape=lpeg.patterns.xmlescape })
-  add(formatters,"tex",[[lpegmatch(texescape,%s)]],{ texescape=lpeg.patterns.texescape })
-  add(formatters,"lua",[[lpegmatch(luaescape,%s)]],{ luaescape=lpeg.patterns.luaescape })
-end
+add(formatters,"xml",[[lpegmatch(xmlescape,%s)]],[[local xmlescape = lpeg.patterns.xmlescape]])
+add(formatters,"tex",[[lpegmatch(texescape,%s)]],[[local texescape = lpeg.patterns.texescape]])
+add(formatters,"lua",[[lpegmatch(luaescape,%s)]],[[local luaescape = lpeg.patterns.luaescape]])
 
 end -- closure
 
@@ -6482,7 +6405,7 @@ local type,next,tonumber,tostring=type,next,tonumber,tostring
 local abs=math.abs
 local insert=table.insert
 local lpegmatch=lpeg.match
-local reversed,concat,remove,sortedkeys=table.reversed,table.concat,table.remove,table.sortedkeys
+local reversed,concat,remove=table.reversed,table.concat,table.remove
 local ioflush=io.flush
 local fastcopy,tohash,derivetable=table.fastcopy,table.tohash,table.derive
 local formatters=string.formatters
@@ -6504,7 +6427,7 @@ local report_otf=logs.reporter("fonts","otf loading")
 local fonts=fonts
 local otf=fonts.handlers.otf
 otf.glists={ "gsub","gpos" }
-otf.version=2.751 
+otf.version=2.749 
 otf.cache=containers.define("fonts","otf",otf.version,true)
 local fontdata=fonts.hashes.identifiers
 local chardata=characters and characters.data 
@@ -6656,7 +6579,6 @@ local valid_fields=table.tohash {
   "upos",
   "use_typo_metrics",
   "uwidth",
-  "validation_state",
   "version",
   "vert_base",
   "weight",
@@ -7123,6 +7045,7 @@ actions["prepare glyphs"]=function(data,filename,raw)
         }
         local altuni=glyph.altuni
         if altuni then
+          local d
           for i=1,#altuni do
             local a=altuni[i]
             local u=a.unicode
@@ -7135,8 +7058,15 @@ actions["prepare glyphs"]=function(data,filename,raw)
                 vv={ [u]=unicode }
                 variants[v]=vv
               end
+            elseif d then
+              d[#d+1]=u
+            else
+              d={ u }
             end
           end
+          if d then
+            duplicates[unicode]=d
+          end
         end
       else
         report_otf("potential problem: glyph %U is used but empty",index)
@@ -7154,49 +7084,47 @@ actions["check encoding"]=function(data,filename,raw)
   local duplicates=resources.duplicates
   local mapdata=raw.map or {}
   local unicodetoindex=mapdata and mapdata.map or {}
-  local indextounicode=mapdata and mapdata.backmap or {}
   local encname=lower(data.enc_name or mapdata.enc_name or "")
   local criterium=0xFFFF
   if find(encname,"unicode") then 
     if trace_loading then
       report_otf("checking embedded unicode map %a",encname)
     end
-      local hash={}
-      for index,unicode in next,indices do 
-        hash[index]=descriptions[unicode]
-      end
-      local reported={}
-      for unicode,index in next,unicodetoindex do
-        if not descriptions[unicode] then
-          local d=hash[index]
-          if d then
-            if d.unicode~=unicode then
-              local c=d.copies
-              if c then
-                c[unicode]=true
-              else
-                d.copies={ [unicode]=true }
+    for unicode,index in next,unicodetoindex do 
+      if unicode<=criterium and not descriptions[unicode] then
+        local parent=indices[index] 
+        if not parent then
+          report_otf("weird, unicode %U points to nowhere with index %H",unicode,index)
+        else
+          local parentdescription=descriptions[parent]
+          if parentdescription then
+            local altuni=parentdescription.altuni
+            if not altuni then
+              altuni={ { unicode=unicode } }
+              parentdescription.altuni=altuni
+              duplicates[parent]={ unicode }
+            else
+              local done=false
+              for i=1,#altuni do
+                if altuni[i].unicode==unicode then
+                  done=true
+                  break
+                end
               end
+              if not done then
+                insert(altuni,{ unicode=unicode })
+                insert(duplicates[parent],unicode)
+              end
+            end
+            if trace_loading then
+              report_otf("weird, unicode %U points to nowhere with index %H",unicode,index)
             end
-          elseif not reported[i] then
-            report_otf("missing index %i",index)
-            reported[i]=true
+          else
+            report_otf("weird, unicode %U points to %U with index %H",unicode,index)
           end
         end
       end
-      for index,data in next,hash do 
-        data.copies=sortedkeys(data.copies)
-      end
-      for index,unicode in next,indices do 
-        local description=hash[index]
-        local copies=description.copies
-        if copies then
-          duplicates[unicode]=copies
-          description.copies=nil
-        else
-          report_otf("copies but no unicode parent %U",unicode)
-        end
-      end
+    end
   elseif properties.cidinfo then
     report_otf("warning: no unicode map, used cidmap %a",properties.cidinfo.usedname)
   else
@@ -7204,7 +7132,6 @@ actions["check encoding"]=function(data,filename,raw)
   end
   if mapdata then
     mapdata.map={} 
-    mapdata.backmap={} 
   end
 end
 actions["add duplicates"]=function(data,filename,raw)
@@ -7215,37 +7142,28 @@ actions["add duplicates"]=function(data,filename,raw)
   local indices=resources.indices 
   local duplicates=resources.duplicates
   for unicode,d in next,duplicates do
-    local nofduplicates=#d
-    if nofduplicates>4 then
-      if trace_loading then
-        report_otf("ignoring excessive duplicates of %U (n=%s)",unicode,nofduplicates)
-      end
-    else
-      for i=1,nofduplicates do
-        local u=d[i]
-        if not descriptions[u] then
-          local description=descriptions[unicode]
-          local n=0
-          for _,description in next,descriptions do
-            if kerns then
-              local kerns=description.kerns
-              for _,k in next,kerns do
-                local ku=k[unicode]
-                if ku then
-                  k[u]=ku
-                  n=n+1
-                end
+    for i=1,#d do
+      local u=d[i]
+      if not descriptions[u] then
+        local description=descriptions[unicode]
+        local duplicate=table.copy(description) 
+        duplicate.comment=format("copy of U+%05X",unicode)
+        descriptions[u]=duplicate
+        local n=0
+        for _,description in next,descriptions do
+          if kerns then
+            local kerns=description.kerns
+            for _,k in next,kerns do
+              local ku=k[unicode]
+              if ku then
+                k[u]=ku
+                n=n+1
               end
             end
           end
-          if u>0 then
-            local duplicate=table.copy(description) 
-            duplicate.comment=format("copy of U+%05X",unicode)
-            descriptions[u]=duplicate
-            if trace_loading then
-              report_otf("duplicating %U to %U with index %H (%s kerns)",unicode,u,description.index,n)
-            end
-          end
+        end
+        if trace_loading then
+          report_otf("duplicating %U to %U with index %H (%s kerns)",unicode,u,description.index,n)
         end
       end
     end
@@ -7969,11 +7887,6 @@ actions["check metadata"]=function(data,filename,raw)
       ttftables[i].data="deleted"
     end
   end
-  if metadata.validation_state and table.contains(metadata.validation_state,"bad_ps_fontname") then
-    local name=file.nameonly(filename)
-    metadata.fontname="bad-fontname-"..name
-    metadata.fullname="bad-fullname-"..name
-  end
 end
 actions["cleanup tables"]=function(data,filename,raw)
   data.resources.indices=nil 
@@ -8271,24 +8184,6 @@ local function otftotfm(specification)
     local features=specification.features.normal
     local rawdata=otf.load(filename,sub,features and features.featurefile)
     if rawdata and next(rawdata) then
-      local descriptions=rawdata.descriptions
-      local duplicates=rawdata.resources.duplicates
-      if duplicates then
-        local nofduplicates,nofduplicated=0,0
-        for parent,list in next,duplicates do
-          for i=1,#list do
-            local unicode=list[i]
-            if not descriptions[unicode] then
-              descriptions[unicode]=descriptions[parent] 
-              nofduplicated=nofduplicated+1
-            end
-          end
-          nofduplicates=nofduplicates+#list
-        end
-        if trace_otf and nofduplicated~=nofduplicates then
-          report_otf("%i extra duplicates copied out of %i",nofduplicated,nofduplicates)
-        end
-      end
       rawdata.lookuphash={}
       tfmdata=copytotfm(rawdata,cache_id)
       if tfmdata and next(tfmdata) then
@@ -8986,12 +8881,26 @@ 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 nodepool=nodes.pool
+local nuts=nodes.nuts
+local nodepool=nuts.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 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 a_kernpair=attributes.private('kernpair')
 local a_ligacomp=attributes.private('ligacomp')
 local a_markbase=attributes.private('markbase')
@@ -9010,21 +8919,21 @@ 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
-  start[a_cursbase]=bound
-  nxt[a_curscurs]=bound
+  setattr(start,a_cursbase,bound)
+  setattr(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=current[a_kernpair]
+    local bound=getattr(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
-      current[a_kernpair]=bound
+      setattr(current,a_kernpair,bound)
       kerns[bound]={ rlmode,x,y,w,h,r2lflag,tfmchr.width }
     end
     return x,y,w,h,bound
@@ -9035,7 +8944,7 @@ function injections.setkern(current,factor,rlmode,x,tfmchr)
   local dx=factor*x
   if dx~=0 then
     local bound=#kerns+1
-    current[a_kernpair]=bound
+    setattr(current,a_kernpair,bound)
     kerns[bound]={ rlmode,dx }
     return dx,bound
   else
@@ -9044,25 +8953,25 @@ 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=base[a_markbase]          
+  local bound=getattr(base,a_markbase)          
   local index=1
   if bound then
     local mb=marks[bound]
     if mb then
       index=#mb+1
       mb[index]={ dx,dy,rlmode }
-      start[a_markmark]=bound
-      start[a_markdone]=index
+      setattr(start,a_markmark,bound)
+      setattr(start,a_markdone,index)
       return dx,dy,bound
     else
-      report_injections("possible problem, %U is base mark without data (id %a)",base.char,bound)
+      report_injections("possible problem, %U is base mark without data (id %a)",getchar(base),bound)
     end
   end
   index=index or 1
   bound=#marks+1
-  base[a_markbase]=bound
-  start[a_markmark]=bound
-  start[a_markdone]=index
+  setattr(base,a_markbase,bound)
+  setattr(start,a_markmark,bound)
+  setattr(start,a_markdone,index)
   marks[bound]={ [index]={ dx,dy,rlmode,baseismark } }
   return dx,dy,bound
 end
@@ -9072,15 +8981,15 @@ 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 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 kp then
         local k=kerns[kp]
         if k[3] then
@@ -9121,21 +9030,23 @@ local function show_result(head)
   local current=head
   local skipping=false
   while current do
-    local id=current.id
+    local id=getid(current)
     if id==glyph_code then
-      report_injections("char: %C, width %p, xoffset %p, yoffset %p",current.char,current.width,current.xoffset,current.yoffset)
+      report_injections("char: %C, width %p, xoffset %p, yoffset %p",
+        getchar(current),getfield(current,"width"),getfield(current,"xoffset"),getfield(current,"yoffset"))
       skipping=false
     elseif id==kern_code then
-      report_injections("kern: %p",current.kern)
+      report_injections("kern: %p",getfield(current,"kern"))
       skipping=false
     elseif not skipping then
       report_injections()
       skipping=true
     end
-    current=current.next
+    current=getnext(current)
   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
@@ -9145,17 +9056,18 @@ 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 n.subtype<256 then
+        if getsubtype(n)<256 then
           nofvalid=nofvalid+1
           valid[nofvalid]=n
-          if n.font~=nf then
-            nf=n.font
-            tm=fontdata[nf].resources.marks
+          local f=getfont(n)
+          if f~=nf then
+            nf=f
+            tm=fontdata[nf].resources.marks 
           end
           if tm then
-            mk[n]=tm[n.char]
+            mk[n]=tm[getchar(n)]
           end
-          local k=n[a_kernpair]
+          local k=getattr(n,a_kernpair)
           if k then
             local kk=kerns[k]
             if kk then
@@ -9175,15 +9087,16 @@ function injections.handler(head,where,keep)
     else
       local nf,tm=nil,nil
       for n in traverse_id(glyph_code,head) do
-        if n.subtype<256 then
+        if getsubtype(n)<256 then
           nofvalid=nofvalid+1
           valid[nofvalid]=n
-          if n.font~=nf then
-            nf=n.font
-            tm=fontdata[nf].resources.marks
+          local f=getfont(n)
+          if f~=nf then
+            nf=f
+            tm=fontdata[nf].resources.marks 
           end
           if tm then
-            mk[n]=tm[n.char]
+            mk[n]=tm[getchar(n)]
           end
         end
       end
@@ -9192,7 +9105,7 @@ function injections.handler(head,where,keep)
       local cx={}
       if has_kerns and next(ky) then
         for n,k in next,ky do
-          n.yoffset=k
+          setfield(n,"yoffset",k)
         end
       end
       if has_cursives then
@@ -9201,9 +9114,9 @@ function injections.handler(head,where,keep)
         for i=1,nofvalid do 
           local n=valid[i]
           if not mk[n] then
-            local n_cursbase=n[a_cursbase]
+            local n_cursbase=getattr(n,a_cursbase)
             if p_cursbase then
-              local n_curscurs=n[a_curscurs]
+              local n_curscurs=getattr(n,a_curscurs)
               if p_cursbase==n_curscurs then
                 local c=cursives[n_curscurs]
                 if c then
@@ -9226,20 +9139,20 @@ function injections.handler(head,where,keep)
                 end
               end
             elseif maxt>0 then
-              local ny=n.yoffset
+              local ny=getfield(n,"yoffset")
               for i=maxt,1,-1 do
                 ny=ny+d[i]
                 local ti=t[i]
-                ti.yoffset=ti.yoffset+ny
+                setfield(ti,"yoffset",getfield(ti,"yoffset")+ny)
               end
               maxt=0
             end
             if not n_cursbase and maxt>0 then
-              local ny=n.yoffset
+              local ny=getfield(n,"yoffset")
               for i=maxt,1,-1 do
                 ny=ny+d[i]
                 local ti=t[i]
-                ti.yoffset=ny
+                setfield(ti,"yoffset",ny)
               end
               maxt=0
             end
@@ -9247,11 +9160,11 @@ function injections.handler(head,where,keep)
           end
         end
         if maxt>0 then
-          local ny=n.yoffset
+          local ny=getfield(n,"yoffset")
           for i=maxt,1,-1 do
             ny=ny+d[i]
             local ti=t[i]
-            ti.yoffset=ny
+            setfield(ti,"yoffset",ny)
           end
           maxt=0
         end
@@ -9262,57 +9175,66 @@ function injections.handler(head,where,keep)
       if has_marks then
         for i=1,nofvalid do
           local p=valid[i]
-          local p_markbase=p[a_markbase]
+          local p_markbase=getattr(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]
+            for n in traverse_id(glyph_code,getnext(p)) do
+              local n_markmark=getattr(n,a_markmark)
               if p_markbase==n_markmark then
-                local index=n[a_markdone] or 1
+                local index=getattr(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
-                        n.xoffset=p.xoffset-p.width+d[1]-(w-x)
+                        ox=px-getfield(p,"width")+d[1]-(w-x)
                       else
-                        n.xoffset=p.xoffset-d[1]-x
+                        ox=px-d[1]-x
                       end
                     else
                       if rlmode and rlmode>=0 then
-                        n.xoffset=p.xoffset-p.width+d[1]
+                        ox=px-getfield(p,"width")+d[1]
                       else
-                        n.xoffset=p.xoffset-d[1]-x
+                        ox=px-d[1]-x
                       end
                     end
                   else
+                    local wp=getfield(p,"width")
+                    local wn=getfield(n,"width") 
                     if rlmode and rlmode>=0 then
-                      n.xoffset=p.xoffset-p.width+d[1]
+                      ox=px-wp+d[1]
                     else
-                      n.xoffset=p.xoffset-d[1]
+                      ox=px-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))
+                    if wn~=0 then
+                      insert_node_before(head,n,newkern(-wn/2))
+                      insert_node_after(head,n,newkern(-wn/2))
                     end
                   end
+                  setfield(n,"xoffset",ox)
+                  local py=getfield(p,"yoffset")
+                  local oy=0
                   if mk[p] then
-                    n.yoffset=p.yoffset+d[2]
+                    oy=py+d[2]
                   else
-                    n.yoffset=n.yoffset+p.yoffset+d[2]
+                    oy=getfield(n,"yoffset")+py+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
@@ -9364,6 +9286,7 @@ 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={},{},{}
@@ -9373,14 +9296,14 @@ function injections.handler(head,where,keep)
       trace(head)
     end
     for n in traverse_id(glyph_code,head) do
-      if n.subtype<256 then
-        local k=n[a_kernpair]
+      if getsubtype(n)<256 then
+        local k=getattr(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 
+              setfield(n,"yoffset",y) 
             end
             if w then
               local wx=w-x
@@ -9411,10 +9334,10 @@ function injections.handler(head,where,keep)
     if not keep then
       kerns={}
     end
-    return head,true
+    return tonode(head),true
   else
   end
-  return head,false
+  return tonode(head),false
 end
 
 end -- closure
@@ -9829,12 +9752,25 @@ 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 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 setmetatableindex=table.setmetatableindex
 local zwnj=0x200C
 local zwj=0x200D
@@ -9945,83 +9881,83 @@ local function pref(kind,lookupname)
   return formatters["feature %a, lookup %a"](kind,lookupname)
 end
 local function copy_glyph(g) 
-  local components=g.components
+  local components=getfield(g,"components")
   if components then
-    g.components=nil
+    setfield(g,"components",nil)
     local n=copy_node(g)
-    g.components=components
+    setfield(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 start.char==char then
+  if start==stop and getchar(start)==char then
     return head,start
   else
-    local prev=start.prev
-    local next=stop.next
-    start.prev=nil
-    stop.next=nil
+    local prev=getprev(start)
+    local next=getnext(stop)
+    setfield(start,"prev",nil)
+    setfield(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
+    setfield(base,"char",char)
+    setfield(base,"subtype",ligature_code)
+    setfield(base,"components",start)
     if prev then
-      prev.next=base
+      setfield(prev,"next",base)
     end
     if next then
-      next.prev=base
+      setfield(next,"prev",base)
     end
-    base.next=next
-    base.prev=prev
+    setfield(base,"next",next)
+    setfield(base,"prev",prev)
     return head,base
   end
 end
 local function getcomponentindex(start)
-  if start.id~=glyph_code then
+  if getid(start)~=glyph_code then
     return 0
-  elseif start.subtype==ligature_code then
+  elseif getsubtype(start)==ligature_code then
     local i=0
-    local components=start.components
+    local components=getfield(start,"components")
     while components do
       i=i+getcomponentindex(components)
-      components=components.next
+      components=getnext(components)
     end
     return i
-  elseif not marks[start.char] then
+  elseif not marks[getchar(start)] then
     return 1
   else
     return 0
   end
 end
 local function toligature(kind,lookupname,head,start,stop,char,markflag,discfound) 
-  if start==stop and start.char==char then
-    start.char=char
+  if start==stop and getchar(start)==char then
+    setfield(start,"char",char)
     return head,start
   end
-  local prev=start.prev
-  local next=stop.next
-  start.prev=nil
-  stop.next=nil
+  local prev=getprev(start)
+  local next=getnext(stop)
+  setfield(start,"prev",nil)
+  setfield(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 
+  setfield(base,"char",char)
+  setfield(base,"subtype",ligature_code)
+  setfield(base,"components",start) 
   if prev then
-    prev.next=base
+    setfield(prev,"next",base)
   end
   if next then
-    next.prev=base
+    setfield(next,"prev",base)
   end
-  base.next=next
-  base.prev=prev
+  setfield(base,"next",next)
+  setfield(base,"prev",prev)
   if not discfound then
     local deletemarks=markflag~="mark"
     local components=start
@@ -10030,42 +9966,42 @@ local function toligature(kind,lookupname,head,start,stop,char,markflag,discfoun
     local head=base
     local current=base
     while start do
-      local char=start.char
+      local char=getchar(start)
       if not marks[char] then
         baseindex=baseindex+componentindex
         componentindex=getcomponentindex(start)
       elseif not deletemarks then 
-        start[a_ligacomp]=baseindex+(start[a_ligacomp] or componentindex)
+        setattr(start,a_ligacomp,baseindex+(getattr(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])
+          logwarning("%s: keep mark %s, gets index %s",pref(kind,lookupname),gref(char),getattr(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=start.next
+      start=getnext(start)
     end
-    local start=current.next
-    while start and start.id==glyph_code do
-      local char=start.char
+    local start=getnext(current)
+    while start and getid(start)==glyph_code do
+      local char=getchar(start)
       if marks[char] then
-        start[a_ligacomp]=baseindex+(start[a_ligacomp] or componentindex)
+        setattr(start,a_ligacomp,baseindex+(getattr(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])
+          logwarning("%s: set mark %s, gets index %s",pref(kind,lookupname),gref(char),getattr(start,a_ligacomp))
         end
       else
         break
       end
-      start=start.next
+      start=getnext(start)
     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))
+    logprocess("%s: replacing %s by single %s",pref(kind,lookupname),gref(getchar(start)),gref(replacement))
   end
-  start.char=replacement
+  setfield(start,"char",replacement)
   return head,start,true
 end
 local function get_alternative_glyph(start,alternatives,value,trace_alternatives)
@@ -10091,7 +10027,7 @@ 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 start.char,trace_alternatives and formatters["invalid value %a, %s"](value,"no change")
+      return getchar(start),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
@@ -10102,25 +10038,25 @@ end
 local function multiple_glyphs(head,start,multiple,ignoremarks)
   local nofmultiples=#multiple
   if nofmultiples>0 then
-    start.char=multiple[1]
+    setfield(start,"char",multiple[1])
     if nofmultiples>1 then
-      local sn=start.next
+      local sn=getnext(start)
       for k=2,nofmultiples do
         local n=copy_node(start) 
-        n.char=multiple[k]
-        n.next=sn
-        n.prev=start
+        setfield(n,"char",multiple[k])
+        setfield(n,"next",sn)
+        setfield(n,"prev",start)
         if sn then
-          sn.prev=n
+          setfield(sn,"prev",n)
         end
-        start.next=n
+        setfield(start,"next",n)
         start=n
       end
     end
     return head,start,true
   else
     if trace_multiples then
-      logprocess("no multiple for %s",gref(start.char))
+      logprocess("no multiple for %s",gref(getchar(start)))
     end
     return head,start,false
   end
@@ -10130,34 +10066,34 @@ 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(start.char),choice,gref(choice),comment)
+      logprocess("%s: replacing %s by alternative %a to %s, %s",pref(kind,lookupname),gref(getchar(start)),choice,gref(choice),comment)
     end
-    start.char=choice
+    setfield(start,"char",choice)
   else
     if trace_alternatives then
-      logwarning("%s: no variant %a for %s, %s",pref(kind,lookupname),value,gref(start.char),comment)
+      logwarning("%s: no variant %a for %s, %s",pref(kind,lookupname),value,gref(getchar(start)),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))
+    logprocess("%s: replacing %s by multiple %s",pref(kind,lookupname),gref(getchar(start)),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
+  local s,stop,discfound=getnext(start),nil,false
+  local startchar=getchar(start)
   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]
+      local id=getid(s)
+      if id==glyph_code and getfont(s)==currentfont and getsubtype(s)<256 then
+        local lg=ligature[getchar(s)]
         if lg then
           stop=s
           ligature=lg
-          s=s.next
+          s=getnext(s)
         else
           break
         end
@@ -10169,9 +10105,9 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
       local lig=ligature.ligature
       if lig then
         if trace_ligatures then
-          local stopchar=stop.char
+          local stopchar=getchar(stop)
           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))
+          logprocess("%s: replacing %s upto %s by ligature %s case 1",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(getchar(start)))
         else
           head,start=markstoligature(kind,lookupname,head,start,stop,lig)
         end
@@ -10182,18 +10118,18 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
   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
+      local id=getid(s)
+      if id==glyph_code and getsubtype(s)<256 then
+        if getfont(s)==currentfont then
+          local char=getchar(s)
           if skipmark and marks[char] then
-            s=s.next
+            s=getnext(s)
           else
             local lg=ligature[char]
             if lg then
               stop=s
               ligature=lg
-              s=s.next
+              s=getnext(s)
             else
               break
             end
@@ -10203,7 +10139,7 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
         end
       elseif id==disc_code then
         discfound=true
-        s=s.next
+        s=getnext(s)
       else
         break
       end
@@ -10212,36 +10148,35 @@ function handlers.gsub_ligature(head,start,kind,lookupname,ligature,sequence)
     if lig then
       if stop then
         if trace_ligatures then
-          local stopchar=stop.char
+          local stopchar=getchar(stop)
           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))
+          logprocess("%s: replacing %s upto %s by ligature %s case 2",pref(kind,lookupname),gref(startchar),gref(stopchar),gref(getchar(start)))
         else
           head,start=toligature(kind,lookupname,head,start,stop,lig,skipmark,discfound)
         end
-        return head,start,true
       else
-        start.char=lig
+        setfield(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=start.char
+  local markchar=getchar(start)
   if marks[markchar] then
-    local base=start.prev 
-    if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
-      local basechar=base.char
+    local base=getprev(start) 
+    if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+      local basechar=getchar(base)
       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
+          base=getprev(base)
+          if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+            basechar=getchar(base)
             if not marks[basechar] then
               break
             end
@@ -10290,16 +10225,16 @@ 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=start.char
+  local markchar=getchar(start)
   if marks[markchar] then
-    local base=start.prev 
-    if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
-      local basechar=base.char
+    local base=getprev(start) 
+    if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+      local basechar=getchar(base)
       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
+          base=getprev(base)
+          if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+            basechar=getchar(base)
             if not marks[basechar] then
               break
             end
@@ -10311,7 +10246,7 @@ function handlers.gpos_mark2ligature(head,start,kind,lookupname,markanchors,sequ
           end
         end
       end
-      local index=start[a_ligacomp]
+      local index=getattr(start,a_ligacomp)
       local baseanchors=descriptions[basechar]
       if baseanchors then
         baseanchors=baseanchors.anchors
@@ -10356,22 +10291,22 @@ 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=start.char
+  local markchar=getchar(start)
   if marks[markchar] then
-    local base=start.prev 
-    local slc=start[a_ligacomp]
+    local base=getprev(start) 
+    local slc=getattr(start,a_ligacomp)
     if slc then 
       while base do
-        local blc=base[a_ligacomp]
+        local blc=getattr(base,a_ligacomp)
         if blc and blc~=slc then
-          base=base.prev
+          base=getprev(base)
         else
           break
         end
       end
     end
-    if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then 
-      local basechar=base.char
+    if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then 
+      local basechar=getchar(base)
       local baseanchors=descriptions[basechar]
       if baseanchors then
         baseanchors=baseanchors.anchors
@@ -10409,20 +10344,20 @@ 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 start[a_cursbase]
+  local alreadydone=cursonce and getattr(start,a_cursbase)
   if not alreadydone then
     local done=false
-    local startchar=start.char
+    local startchar=getchar(start)
     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
+      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)
         if marks[nextchar] then
-          nxt=nxt.next
+          nxt=getnext(nxt)
         else
           local entryanchors=descriptions[nextchar]
           if entryanchors then
@@ -10456,13 +10391,13 @@ 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(start.char),alreadydone)
+      logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(getchar(start)),alreadydone)
     end
     return head,start,false
   end
 end
 function handlers.gpos_single(head,start,kind,lookupname,kerns,sequence)
-  local startchar=start.char
+  local startchar=getchar(start)
   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)
@@ -10470,33 +10405,33 @@ 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=start.next
+  local snext=getnext(start)
   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
+    while snext and getid(snext)==glyph_code and getfont(snext)==currentfont and getsubtype(snext)<256 do
+      local nextchar=getchar(snext)
       local krn=kerns[nextchar]
       if not krn and marks[nextchar] then
         prev=snext
-        snext=snext.next
+        snext=getnext(snext)
       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=start.char
+              local startchar=getchar(start)
               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 startchar=getchar(start)
               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)
@@ -10509,7 +10444,7 @@ 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(prev.char),gref(nextchar))
+            logprocess("%s: inserting kern %s between %s and %s",pref(kind,lookupname),k,gref(getchar(prev)),gref(nextchar))
           end
           done=true
         end
@@ -10544,13 +10479,13 @@ 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=start.char
+  local char=getchar(start)
   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
+    setfield(start,"char",replacement)
     return head,start,true
   else
     return head,start,false
@@ -10563,8 +10498,8 @@ 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 current.id==glyph_code then
-      local currentchar=current.char
+    if getid(current)==glyph_code then
+      local currentchar=getchar(current)
       local lookupname=subtables[1] 
       local replacement=lookuphash[lookupname]
       if not replacement then
@@ -10581,21 +10516,21 @@ 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
-          current.char=replacement
+          setfield(current,"char",replacement)
         end
       end
       return head,start,true
     elseif current==stop then
       break
     else
-      current=current.next
+      current=getnext(current)
     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=start.char
+  local startchar=getchar(start)
   local subtables=currentlookup.subtables
   local lookupname=subtables[1]
   local replacements=lookuphash[lookupname]
@@ -10624,8 +10559,8 @@ 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 current.id==glyph_code then 
-      local currentchar=current.char
+    if getid(current)==glyph_code then 
+      local currentchar=getchar(current)
       local lookupname=subtables[1]
       local alternatives=lookuphash[lookupname]
       if not alternatives then
@@ -10640,7 +10575,7 @@ 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
-            start.char=choice
+            setfield(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)
@@ -10654,14 +10589,14 @@ function chainprocs.gsub_alternate(head,start,stop,kind,chainname,currentcontext
     elseif current==stop then
       break
     else
-      current=current.next
+      current=getnext(current)
     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=start.char
+  local startchar=getchar(start)
   local subtables=currentlookup.subtables
   local lookupname=subtables[1]
   local ligatures=lookuphash[lookupname]
@@ -10676,20 +10611,20 @@ 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=start.next
+      local s=getnext(start)
       local discfound=false
       local last=stop
       local nofreplacements=0
       local skipmark=currentlookup.flags[1]
       while s do
-        local id=s.id
+        local id=getid(s)
         if id==disc_code then
-          s=s.next
+          s=getnext(s)
           discfound=true
         else
-          local schar=s.char
+          local schar=getchar(s)
           if skipmark and marks[schar] then 
-            s=s.next
+            s=getnext(s)
           else
             local lg=ligatures[schar]
             if lg then
@@ -10697,7 +10632,7 @@ function chainprocs.gsub_ligature(head,start,stop,kind,chainname,currentcontext,
               if s==stop then
                 break
               else
-                s=s.next
+                s=getnext(s)
               end
             else
               break
@@ -10714,7 +10649,7 @@ 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(stop.char),gref(l2))
+            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))
           end
         end
         head,start=toligature(kind,lookupname,head,start,stop,l2,currentlookup.flags[1],discfound)
@@ -10723,7 +10658,7 @@ 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(stop.char))
+          logwarning("%s: replacing character %s upto %s by ligature fails",cref(kind,chainname,chainlookupname,lookupname,chainindex),gref(startchar),gref(getchar(stop)))
         end
       end
     end
@@ -10732,7 +10667,7 @@ 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=start.char
+  local markchar=getchar(start)
   if marks[markchar] then
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
@@ -10741,14 +10676,14 @@ function chainprocs.gpos_mark2base(head,start,stop,kind,chainname,currentcontext
       markanchors=markanchors[markchar]
     end
     if markanchors then
-      local base=start.prev 
-      if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
-        local basechar=base.char
+      local base=getprev(start) 
+      if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+        local basechar=getchar(base)
         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
+            base=getprev(base)
+            if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+              basechar=getchar(base)
               if not marks[basechar] then
                 break
               end
@@ -10795,7 +10730,7 @@ 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=start.char
+  local markchar=getchar(start)
   if marks[markchar] then
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
@@ -10804,14 +10739,14 @@ function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcon
       markanchors=markanchors[markchar]
     end
     if markanchors then
-      local base=start.prev 
-      if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then
-        local basechar=base.char
+      local base=getprev(start) 
+      if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+        local basechar=getchar(base)
         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
+            base=getprev(base)
+            if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then
+              basechar=getchar(base)
               if not marks[basechar] then
                 break
               end
@@ -10823,7 +10758,7 @@ function chainprocs.gpos_mark2ligature(head,start,stop,kind,chainname,currentcon
             end
           end
         end
-        local index=start[a_ligacomp]
+        local index=getattr(start,a_ligacomp)
         local baseanchors=descriptions[basechar].anchors
         if baseanchors then
           local baseanchors=baseanchors['baselig']
@@ -10862,7 +10797,7 @@ 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=start.char
+  local markchar=getchar(start)
   if marks[markchar] then
       local subtables=currentlookup.subtables
       local lookupname=subtables[1]
@@ -10871,20 +10806,20 @@ function chainprocs.gpos_mark2mark(head,start,stop,kind,chainname,currentcontext
         markanchors=markanchors[markchar]
       end
       if markanchors then
-        local base=start.prev 
-        local slc=start[a_ligacomp]
+        local base=getprev(start) 
+        local slc=getattr(start,a_ligacomp)
         if slc then 
           while base do
-            local blc=base[a_ligacomp]
+            local blc=getattr(base,a_ligacomp)
             if blc and blc~=slc then
-              base=base.prev
+              base=getprev(base)
             else
               break
             end
           end
         end
-        if base and base.id==glyph_code and base.font==currentfont and base.subtype<256 then 
-          local basechar=base.char
+        if base and getid(base)==glyph_code and getfont(base)==currentfont and getsubtype(base)<256 then 
+          local basechar=getchar(base)
           local baseanchors=descriptions[basechar].anchors
           if baseanchors then
             baseanchors=baseanchors['basemark']
@@ -10920,9 +10855,9 @@ 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 start[a_cursbase]
+  local alreadydone=cursonce and getattr(start,a_cursbase)
   if not alreadydone then
-    local startchar=start.char
+    local startchar=getchar(start)
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
     local exitanchors=lookuphash[lookupname]
@@ -10936,11 +10871,11 @@ 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=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
+        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)
           if marks[nextchar] then
-            nxt=nxt.next
+            nxt=getnext(nxt)
           else
             local entryanchors=descriptions[nextchar]
             if entryanchors then
@@ -10974,7 +10909,7 @@ 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(start.char),alreadydone)
+        logprocess("%s, cursive %s is already done",pref(kind,lookupname),gref(getchar(start)),alreadydone)
       end
       return head,start,false
     end
@@ -10982,7 +10917,7 @@ 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=start.char
+  local startchar=getchar(start)
   local subtables=currentlookup.subtables
   local lookupname=subtables[1]
   local kerns=lookuphash[lookupname]
@@ -10999,9 +10934,9 @@ 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=start.next
+  local snext=getnext(start)
   if snext then
-    local startchar=start.char
+    local startchar=getchar(start)
     local subtables=currentlookup.subtables
     local lookupname=subtables[1]
     local kerns=lookuphash[lookupname]
@@ -11011,26 +10946,26 @@ 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 snext.id==glyph_code and snext.font==currentfont and snext.subtype<256 do
-          local nextchar=snext.char
+        while snext and getid(snext)==glyph_code and getfont(snext)==currentfont and getsubtype(snext)<256 do
+          local nextchar=getchar(snext)
           local krn=kerns[nextchar]
           if not krn and marks[nextchar] then
             prev=snext
-            snext=snext.next
+            snext=getnext(snext)
           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=start.char
+                  local startchar=getchar(start)
                   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 startchar=getchar(start)
                   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)
@@ -11042,7 +10977,7 @@ 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(prev.char),gref(nextchar))
+                    logprocess("%s: inserting first kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(getchar(prev)),gref(nextchar))
                   end
                 end
                 if b and b~=0 then
@@ -11053,7 +10988,7 @@ 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(prev.char),gref(nextchar))
+                logprocess("%s: inserting kern %s between %s and %s",cref(kind,chainname,chainlookupname),k,gref(getchar(prev)),gref(nextchar))
               end
               done=true
             end
@@ -11074,6 +11009,10 @@ 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
@@ -11091,7 +11030,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
     local seq=ck[3]
     local s=#seq
     if s==1 then
-      match=current.id==glyph_code and current.font==currentfont and current.subtype<256 and seq[1][current.char]
+      match=getid(current)==glyph_code and getfont(current)==currentfont and getsubtype(current)<256 and seq[1][getchar(current)]
     else
       local f,l=ck[4],ck[5]
       if f==1 and f==l then
@@ -11099,13 +11038,13 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
         if f==l then
         else
           local n=f+1
-          last=last.next
+          last=getnext(last)
           while n<=l do
             if last then
-              local id=last.id
+              local id=getid(last)
               if id==glyph_code then
-                if last.font==currentfont and last.subtype<256 then
-                  local char=last.char
+                if getfont(last)==currentfont and getsubtype(last)<256 then
+                  local char=getchar(last)
                   local ccd=descriptions[char]
                   if ccd then
                     local class=ccd.class
@@ -11114,10 +11053,10 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                       if trace_skips then
                         show_skip(kind,chainname,char,ck,class)
                       end
-                      last=last.next
+                      last=getnext(last)
                     elseif seq[n][char] then
                       if n<l then
-                        last=last.next
+                        last=getnext(last)
                       end
                       n=n+1
                     else
@@ -11133,7 +11072,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                   break
                 end
               elseif id==disc_code then
-                last=last.next
+                last=getnext(last)
               else
                 match=false
                 break
@@ -11146,15 +11085,15 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
         end
       end
       if match and f>1 then
-        local prev=start.prev
+        local prev=getprev(start)
         if prev then
           local n=f-1
           while n>=1 do
             if prev then
-              local id=prev.id
+              local id=getid(prev)
               if id==glyph_code then
-                if prev.font==currentfont and prev.subtype<256 then 
-                  local char=prev.char
+                if getfont(prev)==currentfont and getsubtype(prev)<256 then 
+                  local char=getchar(prev)
                   local ccd=descriptions[char]
                   if ccd then
                     local class=ccd.class
@@ -11184,7 +11123,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                 match=false
                 break
               end
-              prev=prev.prev
+              prev=getprev(prev)
             elseif seq[n][32] then 
               n=n -1
             else
@@ -11204,15 +11143,15 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
         end
       end
       if match and s>l then
-        local current=last and last.next
+        local current=last and getnext(last)
         if current then
           local n=l+1
           while n<=s do
             if current then
-              local id=current.id
+              local id=getid(current)
               if id==glyph_code then
-                if current.font==currentfont and current.subtype<256 then 
-                  local char=current.char
+                if getfont(current)==currentfont and getsubtype(current)<256 then 
+                  local char=getchar(current)
                   local ccd=descriptions[char]
                   if ccd then
                     local class=ccd.class
@@ -11242,7 +11181,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
                 match=false
                 break
               end
-              current=current.next
+              current=getnext(current)
             elseif seq[n][32] then
               n=n+1
             else
@@ -11265,7 +11204,7 @@ 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=start.char
+        local char=getchar(start)
         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])
@@ -11299,12 +11238,12 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
           repeat
             if skipped then
               while true do
-                local char=start.char
+                local char=getchar(start)
                 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
+                    start=getnext(start)
                   else
                     break
                   end
@@ -11334,7 +11273,7 @@ local function normal_handle_contextchain(head,start,kind,chainname,contexts,seq
               end
             end
             if start then
-              start=start.next
+              start=getnext(start)
             else
             end
           until i>nofchainlookups
@@ -11344,7 +11283,7 @@ 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=true 
+          done=quit_on_no_replacement 
           if trace_contexts then
             logprocess("%s: skipping match",cref(kind,chainname))
           end
@@ -11461,6 +11400,7 @@ local function featuresprocessor(head,font,attr)
   if not lookuphash then
     return head,false
   end
+  head=tonut(head)
   if trace_steps then
     checkstep(head)
   end
@@ -11493,10 +11433,10 @@ local function featuresprocessor(head,font,attr)
       local handler=handlers[typ]
       local start=find_node_tail(head) 
       while start do
-        local id=start.id
+        local id=getid(start)
         if id==glyph_code then
-          if start.font==font and start.subtype<256 then
-            local a=start[0]
+          if getfont(start)==font and getsubtype(start)<256 then
+            local a=getattr(start,0)
             if a then
               a=a==attr
             else
@@ -11507,7 +11447,7 @@ local function featuresprocessor(head,font,attr)
                 local lookupname=subtables[i]
                 local lookupcache=lookuphash[lookupname]
                 if lookupcache then
-                  local lookupmatch=lookupcache[start.char]
+                  local lookupmatch=lookupcache[getchar(start)]
                   if lookupmatch then
                     head,start,success=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
                     if success then
@@ -11518,15 +11458,15 @@ local function featuresprocessor(head,font,attr)
                   report_missing_cache(typ,lookupname)
                 end
               end
-              if start then start=start.prev end
+              if start then start=getprev(start) end
             else
-              start=start.prev
+              start=getprev(start)
             end
           else
-            start=start.prev
+            start=getprev(start)
           end
         else
-          start=start.prev
+          start=getprev(start)
         end
       end
     else
@@ -11544,16 +11484,16 @@ local function featuresprocessor(head,font,attr)
             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]
+              local id=getid(start)
+              if id==glyph_code and getfont(start)==font and getsubtype(start)<256 then
+                local a=getattr(start,0)
                 if a then
-                  a=(a==attr) and (not attribute or start[a_state]==attribute)
+                  a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
                 else
-                  a=not attribute or start[a_state]==attribute
+                  a=not attribute or getattr(start,a_state)==attribute
                 end
                 if a then
-                  local lookupmatch=lookupcache[start.char]
+                  local lookupmatch=lookupcache[getchar(start)]
                   if lookupmatch then
                     local ok
                     head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
@@ -11561,12 +11501,12 @@ local function featuresprocessor(head,font,attr)
                       done=true
                     end
                   end
-                  if start then start=start.next end
+                  if start then start=getnext(start) end
                 else
-                  start=start.next
+                  start=getnext(start)
                 end
               else
-                start=start.next
+                start=getnext(start)
               end
             end
             if done then
@@ -11575,18 +11515,18 @@ local function featuresprocessor(head,font,attr)
             end
           end
           local function kerndisc(disc) 
-            local prev=disc.prev
-            local next=disc.next
+            local prev=getprev(disc)
+            local next=getnext(disc)
             if prev and next then
-              prev.next=next
-              local a=prev[0]
+              setfield(prev,"next",next)
+              local a=getattr(prev,0)
               if a then
-                a=(a==attr) and (not attribute or prev[a_state]==attribute)
+                a=(a==attr) and (not attribute or getattr(prev,a_state)==attribute)
               else
-                a=not attribute or prev[a_state]==attribute
+                a=not attribute or getattr(prev,a_state)==attribute
               end
               if a then
-                local lookupmatch=lookupcache[prev.char]
+                local lookupmatch=lookupcache[getchar(prev)]
                 if lookupmatch then
                   local h,d,ok=handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
                   if ok then
@@ -11595,22 +11535,22 @@ local function featuresprocessor(head,font,attr)
                   end
                 end
               end
-              prev.next=disc
+              setfield(prev,"next",disc)
             end
             return next
           end
           while start do
-            local id=start.id
+            local id=getid(start)
             if id==glyph_code then
-              if start.font==font and start.subtype<256 then
-                local a=start[0]
+              if getfont(start)==font and getsubtype(start)<256 then
+                local a=getattr(start,0)
                 if a then
-                  a=(a==attr) and (not attribute or start[a_state]==attribute)
+                  a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
                 else
-                  a=not attribute or start[a_state]==attribute
+                  a=not attribute or getattr(start,a_state)==attribute
                 end
                 if a then
-                  local lookupmatch=lookupcache[start.char]
+                  local lookupmatch=lookupcache[getchar(start)]
                   if lookupmatch then
                     local ok
                     head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,1)
@@ -11618,38 +11558,38 @@ local function featuresprocessor(head,font,attr)
                       success=true
                     end
                   end
-                  if start then start=start.next end
+                  if start then start=getnext(start) end
                 else
-                  start=start.next
+                  start=getnext(start)
                 end
               else
-                start=start.next
+                start=getnext(start)
               end
             elseif id==disc_code then
-              if start.subtype==discretionary_code then
-                local pre=start.pre
+              if getsubtype(start)==discretionary_code then
+                local pre=getfield(start,"pre")
                 if pre then
                   local new=subrun(pre)
-                  if new then start.pre=new end
+                  if new then setfield(start,"pre",new) end
                 end
-                local post=start.post
+                local post=getfield(start,"post")
                 if post then
                   local new=subrun(post)
-                  if new then start.post=new end
+                  if new then setfield(start,"post",new) end
                 end
-                local replace=start.replace
+                local replace=getfield(start,"replace")
                 if replace then
                   local new=subrun(replace)
-                  if new then start.replace=new end
+                  if new then setfield(start,"replace",new) end
                 end
 elseif typ=="gpos_single" or typ=="gpos_pair" then
   kerndisc(start)
               end
-              start=start.next
+              start=getnext(start)
             elseif id==whatsit_code then 
-              local subtype=start.subtype
+              local subtype=getsubtype(start)
               if subtype==dir_code then
-                local dir=start.dir
+                local dir=getfield(start,"dir")
                 if   dir=="+TRT" or dir=="+TLT" then
                   topstack=topstack+1
                   dirstack[topstack]=dir
@@ -11668,7 +11608,7 @@ 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=start.dir
+                local dir=getfield(start,"dir")
                 if dir=="TRT" then
                   rlparmode=-1
                 elseif dir=="TLT" then
@@ -11681,11 +11621,11 @@ 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=start.next
+              start=getnext(start)
             elseif id==math_code then
-              start=end_of_math(start).next
+              start=getnext(end_of_math(start))
             else
-              start=start.next
+              start=getnext(start)
             end
           end
         end
@@ -11694,20 +11634,20 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
           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]
+            local id=getid(start)
+            if id==glyph_code and getfont(start)==font and getsubtype(start)<256 then
+              local a=getattr(start,0)
               if a then
-                a=(a==attr) and (not attribute or start[a_state]==attribute)
+                a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
               else
-                a=not attribute or start[a_state]==attribute
+                a=not attribute or getattr(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]
+                    local lookupmatch=lookupcache[getchar(start)]
                     if lookupmatch then
                       local ok
                       head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
@@ -11722,12 +11662,12 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                     report_missing_cache(typ,lookupname)
                   end
                 end
-                if start then start=start.next end
+                if start then start=getnext(start) end
               else
-                start=start.next
+                start=getnext(start)
               end
             else
-              start=start.next
+              start=getnext(start)
             end
           end
           if done then
@@ -11736,22 +11676,22 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
           end
         end
         local function kerndisc(disc) 
-          local prev=disc.prev
-          local next=disc.next
+          local prev=getprev(disc)
+          local next=getnext(disc)
           if prev and next then
-            prev.next=next
-            local a=prev[0]
+            setfield(prev,"next",next)
+            local a=getattr(prev,0)
             if a then
-              a=(a==attr) and (not attribute or prev[a_state]==attribute)
+              a=(a==attr) and (not attribute or getattr(prev,a_state)==attribute)
             else
-              a=not attribute or prev[a_state]==attribute
+              a=not attribute or getattr(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]
+                  local lookupmatch=lookupcache[getchar(prev)]
                   if lookupmatch then
                     local h,d,ok=handler(head,prev,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
                     if ok then
@@ -11764,26 +11704,26 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                 end
               end
             end
-            prev.next=disc
+            setfield(prev,"next",disc)
           end
           return next
         end
         while start do
-          local id=start.id
+          local id=getid(start)
           if id==glyph_code then
-            if start.font==font and start.subtype<256 then
-              local a=start[0]
+            if getfont(start)==font and getsubtype(start)<256 then
+              local a=getattr(start,0)
               if a then
-                a=(a==attr) and (not attribute or start[a_state]==attribute)
+                a=(a==attr) and (not attribute or getattr(start,a_state)==attribute)
               else
-                a=not attribute or start[a_state]==attribute
+                a=not attribute or getattr(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]
+                    local lookupmatch=lookupcache[getchar(start)]
                     if lookupmatch then
                       local ok
                       head,start,ok=handler(head,start,dataset[4],lookupname,lookupmatch,sequence,lookuphash,i)
@@ -11798,38 +11738,38 @@ elseif typ=="gpos_single" or typ=="gpos_pair" then
                     report_missing_cache(typ,lookupname)
                   end
                 end
-                if start then start=start.next end
+                if start then start=getnext(start) end
               else
-                start=start.next
+                start=getnext(start)
               end
             else
-              start=start.next
+              start=getnext(start)
             end
           elseif id==disc_code then
-            if start.subtype==discretionary_code then
-              local pre=start.pre
+            if getsubtype(start)==discretionary_code then
+              local pre=getfield(start,"pre")
               if pre then
                 local new=subrun(pre)
-                if new then start.pre=new end
+                if new then setfield(start,"pre",new) end
               end
-              local post=start.post
+              local post=getfield(start,"post")
               if post then
                 local new=subrun(post)
-                if new then start.post=new end
+                if new then setfield(start,"post",new) end
               end
-              local replace=start.replace
+              local replace=getfield(start,"replace")
               if replace then
                 local new=subrun(replace)
-                if new then start.replace=new end
+                if new then setfield(start,"replace",new) end
               end
 elseif typ=="gpos_single" or typ=="gpos_pair" then
   kerndisc(start)
             end
-            start=start.next
+            start=getnext(start)
           elseif id==whatsit_code then
-            local subtype=start.subtype
+            local subtype=getsubtype(start)
             if subtype==dir_code then
-              local dir=start.dir
+              local dir=getfield(start,"dir")
               if   dir=="+TRT" or dir=="+TLT" then
                 topstack=topstack+1
                 dirstack[topstack]=dir
@@ -11848,7 +11788,7 @@ 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=start.dir
+              local dir=getfield(start,"dir")
               if dir=="TRT" then
                 rlparmode=-1
               elseif dir=="TLT" then
@@ -11861,11 +11801,11 @@ 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=start.next
+            start=getnext(start)
           elseif id==math_code then
-            start=end_of_math(start).next
+            start=getnext(end_of_math(start))
           else
-            start=start.next
+            start=getnext(start)
           end
         end
       end
@@ -11877,6 +11817,7 @@ 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)