1 files changed, 1222 insertions, 1222 deletions
diff --git a/tex/context/base/node-fin.lua b/tex/context/base/node-fin.lua
index e95725d29..2e62ebcb5 100644
--- a/tex/context/base/node-fin.lua
+++ b/tex/context/base/node-fin.lua
@@ -1,1222 +1,1222 @@
-if not modules then modules = { } end modules ['node-fin'] = {
-    version   = 1.001,
-    comment   = "companion to node-fin.mkiv",
-    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
-    copyright = "PRAGMA ADE / ConTeXt Development Team",
-    license   = "see context related readme files",
-}
-
--- this module is being reconstructed
--- local functions, only slightly slower
-
-local next, type, format = next, type, string.format
-
-local attributes, nodes, node = attributes, nodes, node
-
-local copy_node       = node.copy
-local find_tail       = node.slide
-
-local nodecodes       = nodes.nodecodes
-local whatcodes       = nodes.whatcodes
-
-local glyph_code      = nodecodes.glyph
-local disc_code       = nodecodes.disc
-local glue_code       = nodecodes.glue
-local rule_code       = nodecodes.rule
-local whatsit_code    = nodecodes.whatsit
-local hlist_code      = nodecodes.hlist
-local vlist_code      = nodecodes.vlist
-
-local pdfliteral_code = whatcodes.pdfliteral
-
-local states          = attributes.states
-local numbers         = attributes.numbers
-local a_trigger       = attributes.private('trigger')
-local triggering      = false
-
-local starttiming     = statistics.starttiming
-local stoptiming      = statistics.stoptiming
-local loadstripped    = utilities.lua.loadstripped
-local unsetvalue      = attributes.unsetvalue
-
--- these two will be like trackers
-
-function states.enabletriggering()
-    triggering = true
-end
-function states.disabletriggering()
-    triggering = false
-end
-
--- the following code is no longer needed due to the new backend
--- but we keep it around for a while as an example
---
--- states.collected = states.collected or { }
---
--- storage.register("states/collected", states.collected, "states.collected")
---
--- local collected = states.collected
---
--- function states.collect(str)
---     collected[#collected+1] = str
--- end
---
--- function states.flush()
---     if #collected > 0 then
---         for i=1,#collected do
---             context(collected[i]) -- we're in context mode anyway
---         end
---         collected = { }
---         states.collected = collected
---     end
--- end
---
--- function states.check()
---     logs.report("states",concat(collected,"\n"))
--- end
-
--- we used to do the main processor loop here and call processor for each node
--- but eventually this was too much a slow down (1 sec on 23 for 120 pages mk)
--- so that we moved looping to the processor itself; this may lead to a bit of
--- duplicate code once that we have more state handlers
-
--- local function process_attribute(head,plugin) -- head,attribute,enabled,initializer,resolver,processor,finalizer
---     local namespace = plugin.namespace
---     if namespace.enabled ~= false then -- this test will go away
---         starttiming(attributes) -- in principle we could delegate this to the main caller
---         local done, used, ok = false, nil, false
---         local attribute = namespace.attribute or numbers[plugin.name] -- todo: plugin.attribute
---         local processor = plugin.processor
---         if processor then
---             local initializer = plugin.initializer
---             local resolver    = plugin.resolver
---             local inheritance = (resolver and resolver()) or nil -- -0x7FFFFFFF -- we can best use nil and skip !
---             if initializer then
---                 initializer(namespace,attribute,head)
---             end
---             head, ok = processor(namespace,attribute,head,inheritance)
---             if ok then
---                 local finalizer = plugin.finalizer
---                 if finalizer then
---                     head, ok, used = finalizer(namespace,attribute,head)
---                     if used then
---                         local flusher = plugin.flusher
---                         if flusher then
---                             head = flusher(namespace,attribute,head,used)
---                         end
---                     end
---                 end
---                 done = true
---             end
---         end
---         stoptiming(attributes)
---         return head, done
---     else
---         return head, false
---     end
--- end
---
--- function nodes.installattributehandler(plugin) -- we need to avoid this nested function
---     return function(head)
---         return process_attribute(head,plugin)
---     end
--- end
-
--- An experiment: lean and mean functions. It is not really faster but
--- with upcoming functionality it might make a difference, e.g. features
--- like 'casing' and 'italics' can be called a lot so there it makes sense.
-
-nodes.plugindata = nil
-
-local template = [[
-local plugin = nodes.plugindata
-local starttiming = statistics.starttiming
-local stoptiming = statistics.stoptiming
-local namespace = plugin.namespace
-local attribute = namespace.attribute or attributes.numbers[plugin.name]
-local processor = plugin.processor
-local initializer = plugin.initializer
-local resolver = plugin.resolver
-local finalizer = plugin.finalizer
-local flusher = plugin.flusher
-if not processor then
-    return function(head)
-        return head, false
-    end
-elseif initializer or finalizer or resolver then
-    return function(head)
-        starttiming(attributes)
-        local done, used, ok = false, nil, false
-        local inheritance = (resolver and resolver()) or nil -- -0x7FFFFFFF -- we can best use nil and skip !
-        if initializer then
-            initializer(namespace,attribute,head)
-        end
-        head, ok = processor(namespace,attribute,head,inheritance)
-        if ok then
-            if finalizer then
-                head, ok, used = finalizer(namespace,attribute,head)
-                if used and flusher then
-                    head = flusher(namespace,attribute,head,used)
-                end
-            end
-            done = true
-        end
-        stoptiming(attributes)
-        return head, done
-    end
-else
-    return function(head)
-        starttiming(attributes)
-        local head, done = processor(namespace,attribute,head)
-        stoptiming(attributes)
-        return head, done
-    end
-end
-nodes.plugindata = nil
-]]
-
-function nodes.installattributehandler(plugin)
-    nodes.plugindata = plugin
-    return loadstripped(template)()
-end
-
--- the injectors
-
-local insert_node_before = node.insert_before
-local insert_node_after  = node.insert_after
-
-local nsdata, nsnone, nslistwise, nsforced, nsselector, nstrigger
-local current, current_selector, done = 0, 0, false -- nb, stack has a local current !
-local nsbegin, nsend
-
-function states.initialize(namespace,attribute,head)
-    nsdata           = namespace.data
-    nsnone           = namespace.none
-    nsforced         = namespace.forced
-    nsselector       = namespace.selector
-    nslistwise       = namespace.listwise
-    nstrigger        = triggering and namespace.triggering and a_trigger
-    current          = 0
-    current_selector = 0
-    done             = false -- todo: done cleanup
-    nsstep           = namespace.resolve_step
-    if nsstep then
-        nsbegin      = namespace.resolve_begin
-        nsend        = namespace.resolve_end
-        nspush       = namespace.push
-        nspop        = namespace.pop
-    end
-end
-
-function states.finalize(namespace,attribute,head) -- is this one ok?
-    if current > 0 and nsnone then
-        local id = head.id
-        if id == hlist_code or id == vlist_code then
-            local list = head.list
-            if list then
-                head.list = insert_node_before(list,list,copy_node(nsnone))
-            end
-        else
-            head = insert_node_before(head,head,copy_node(nsnone))
-        end
-        return head, true, true
-    end
-    return head, false, false
-end
-
--- disc nodes can be ignored
--- we need to deal with literals too (reset as well as oval)
--- if id == glyph_code or (id == whatsit_code and stack.subtype == pdfliteral_code) or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then
-
--- local function process(namespace,attribute,head,inheritance,default) -- one attribute
---     local stack, done = head, false
---     while stack do
---         local id = stack.id
---         if id == glyph_code or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then -- or disc_code
---             local c = stack[attribute]
---             if c then
---                 if default and c == inheritance then
---                     if current ~= default then
---                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                         current = default
---                         done = true
---                     end
---                 elseif current ~= c then
---                     head = insert_node_before(head,stack,copy_node(nsdata[c]))
---                     current = c
---                     done = true
---                 end
---                 -- here ? compare selective
---                 if id == glue_code then --leader
---                     -- same as *list
---                     local content = stack.leader
---                     if content then
---                         local savedcurrent = current
---                         local ci = content.id
---                         if ci == hlist_code or ci == vlist_code then
---                             -- else we reset inside a box unneeded, okay, the downside is
---                             -- that we trigger color in each repeated box, so there is room
---                             -- for improvement here
---                             current = 0
---                         end
---                         local ok = false
---                         if nstrigger and stack[nstrigger] then
---                             local outer = stack[attribute]
---                             if outer ~= inheritance then
---                                 stack.leader, ok = process(namespace,attribute,content,inheritance,outer)
---                             else
---                                 stack.leader, ok = process(namespace,attribute,content,inheritance,default)
---                             end
---                         else
---                             stack.leader, ok = process(namespace,attribute,content,inheritance,default)
---                         end
---                         current = savedcurrent
---                         done = done or ok
---                     end
---                 end
---             elseif default and inheritance then
---                 if current ~= default then
---                     head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                     current = default
---                     done = true
---                 end
---             elseif current > 0 then
---                 head = insert_node_before(head,stack,copy_node(nsnone))
---                 current = 0
---                 done = true
---             end
---         elseif id == hlist_code or id == vlist_code then
---             local content = stack.list
---             if content then
---                 local ok = false
---                 if nstrigger and stack[nstrigger] then
---                     local outer = stack[attribute]
---                     if outer ~= inheritance then
---                         stack.list, ok = process(namespace,attribute,content,inheritance,outer)
---                     else
---                         stack.list, ok = process(namespace,attribute,content,inheritance,default)
---                     end
---                 else
---                     stack.list, ok = process(namespace,attribute,content,inheritance,default)
---                 end
---                 done = done or ok
---             end
---         end
---         stack = stack.next
---     end
---     return head, done
--- end
-
--- local function process(namespace,attribute,head,inheritance,default) -- one attribute
---     local stack, done = head, false
-
---     local function check()
---         local c = stack[attribute]
---         if c then
---             if default and c == inheritance then
---                 if current ~= default then
---                     head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                     current = default
---                     done = true
---                 end
---             elseif current ~= c then
---                 head = insert_node_before(head,stack,copy_node(nsdata[c]))
---                 current = c
---                 done = true
---             end
---         elseif default and inheritance then
---             if current ~= default then
---                 head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                 current = default
---                 done = true
---             end
---         elseif current > 0 then
---             head = insert_node_before(head,stack,copy_node(nsnone))
---             current = 0
---             done = true
---         end
---         return c
---     end
-
---     local function nested(content)
---         if nstrigger and stack[nstrigger] then
---             local outer = stack[attribute]
---             if outer ~= inheritance then
---                 return process(namespace,attribute,content,inheritance,outer)
---             else
---                 return process(namespace,attribute,content,inheritance,default)
---             end
---         else
---             return process(namespace,attribute,content,inheritance,default)
---         end
---     end
-
---     while stack do
---         local id = stack.id
---         if id == glyph_code then
---             check()
---         elseif id == glue_code then
---             local content = stack.leader
---             if content and check() then
---                 local savedcurrent = current
---                 local ci = content.id
---                 if ci == hlist_code or ci == vlist_code then
---                     -- else we reset inside a box unneeded, okay, the downside is
---                     -- that we trigger color in each repeated box, so there is room
---                     -- for improvement here
---                     current = 0
---                 end
-
---                 local ok = false
---                 stack.leader, ok = nested(content)
---                 done = done or ok
-
---                 current = savedcurrent
---             end
---         elseif id == hlist_code or id == vlist_code then
---             local content = stack.list
---             if content then
-
---                 local ok = false
---                 stack.list, ok = nested(content)
---                 done = done or ok
-
---             end
---         elseif id == rule_code then
---             if stack.width ~= 0 then
---                 check()
---             end
---         end
---         stack = stack.next
---     end
---     return head, done
--- end
-
--- local function process(namespace,attribute,head,inheritance,default) -- one attribute
---     local stack, done = head, false
---     while stack do
---         local id = stack.id
---         if id == glyph_code then
---             -- begin of check
---             local c = stack[attribute]
---             if c then
---                 if default and c == inheritance then
---                     if current ~= default then
---                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                         current = default
---                         done = true
---                     end
---                 elseif current ~= c then
---                     head = insert_node_before(head,stack,copy_node(nsdata[c]))
---                     current = c
---                     done = true
---                 end
---             elseif default and inheritance then
---                 if current ~= default then
---                     head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                     current = default
---                     done = true
---                 end
---             elseif current > 0 then
---                 head = insert_node_before(head,stack,copy_node(nsnone))
---                 current = 0
---                 done = true
---             end
---             -- end of check
---         elseif id == glue_code then
---             local content = stack.leader
---             if content then
---                 -- begin of check
---                 local c = stack[attribute]
---                 if c then
---                     if default and c == inheritance then
---                         if current ~= default then
---                             head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                             current = default
---                             done = true
---                         end
---                     elseif current ~= c then
---                         head = insert_node_before(head,stack,copy_node(nsdata[c]))
---                         current = c
---                         done = true
---                     end
---                     -- begin special to this check
---                     local savedcurrent = current
---                     local ci = content.id
---                     if ci == hlist_code or ci == vlist_code then
---                         -- else we reset inside a box unneeded, okay, the downside is
---                         -- that we trigger color in each repeated box, so there is room
---                         -- for improvement here
---                         current = 0
---                     end
---                     -- begin nested --
---                     local ok = false
---                     if nstrigger and stack[nstrigger] then
---                         local outer = stack[attribute]
---                         if outer ~= inheritance then
---                             stack.leader, ok = process(namespace,attribute,content,inheritance,outer)
---                         else
---                             stack.leader, ok = process(namespace,attribute,content,inheritance,default)
---                         end
---                     else
---                         stack.leader, ok = process(namespace,attribute,content,inheritance,default)
---                     end
---                     -- end nested --
---                     done = done or ok
---                     current = savedcurrent
---                     -- end special to this check
---                 elseif default and inheritance then
---                     if current ~= default then
---                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                         current = default
---                         done = true
---                     end
---                 elseif current > 0 then
---                     head = insert_node_before(head,stack,copy_node(nsnone))
---                     current = 0
---                     done = true
---                 end
---                 -- end of check
---             end
---         elseif id == hlist_code or id == vlist_code then
---             local content = stack.list
---             if content then
---                 -- begin nested --
---                 local ok
---                 if nstrigger and stack[nstrigger] then
---                     local outer = stack[attribute]
---                     if outer ~= inheritance then
---                         stack.list, ok = process(namespace,attribute,content,inheritance,outer)
---                     else
---                         stack.list, ok = process(namespace,attribute,content,inheritance,default)
---                     end
---                 else
---                     stack.list, ok = process(namespace,attribute,content,inheritance,default)
---                 end
---                 -- end nested --
---                 done = done or ok
---             end
---         elseif id == rule_code then
---             if stack.width ~= 0 then
---                 -- begin of check
---                 local c = stack[attribute]
---                 if c then
---                     if default and c == inheritance then
---                         if current ~= default then
---                             head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                             current = default
---                             done = true
---                         end
---                     elseif current ~= c then
---                         head = insert_node_before(head,stack,copy_node(nsdata[c]))
---                         current = c
---                         done = true
---                     end
---                 elseif default and inheritance then
---                     if current ~= default then
---                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
---                         current = default
---                         done = true
---                     end
---                 elseif current > 0 then
---                     head = insert_node_before(head,stack,copy_node(nsnone))
---                     current = 0
---                     done = true
---                 end
---                 -- end of check
---             end
---         end
---         stack = stack.next
---     end
---     return head, done
--- end
-
-local function process(namespace,attribute,head,inheritance,default) -- one attribute
-    local stack  = head
-    local done   = false
-    local check  = false
-    local leader = nil
-    while stack do
-        local id = stack.id
-        if id == glyph_code then
-            check = true
-        elseif id == glue_code then
-            leader = stack.leader
-            if leader then
-                check = true
-            end
-        elseif id == hlist_code or id == vlist_code then
-            local content = stack.list
-            if content then
-                -- begin nested --
-                local ok
-                if nstrigger and stack[nstrigger] then
-                    local outer = stack[attribute]
-                    if outer ~= inheritance then
-                        stack.list, ok = process(namespace,attribute,content,inheritance,outer)
-                    else
-                        stack.list, ok = process(namespace,attribute,content,inheritance,default)
-                    end
-                else
-                    stack.list, ok = process(namespace,attribute,content,inheritance,default)
-                end
-                -- end nested --
-                done = done or ok
-            end
-        elseif id == rule_code then
-            check = stack.width ~= 0
-        end
-        -- much faster this way than using a check() and nested() function
-        if check then
-            local c = stack[attribute]
-            if c then
-                if default and c == inheritance then
-                    if current ~= default then
-                        head = insert_node_before(head,stack,copy_node(nsdata[default]))
-                        current = default
-                        done = true
-                    end
-                elseif current ~= c then
-                    head = insert_node_before(head,stack,copy_node(nsdata[c]))
-                    current = c
-                    done = true
-                end
-                if leader then
-                    local savedcurrent = current
-                    local ci = leader.id
-                    if ci == hlist_code or ci == vlist_code then
-                        -- else we reset inside a box unneeded, okay, the downside is
-                        -- that we trigger color in each repeated box, so there is room
-                        -- for improvement here
-                        current = 0
-                    end
-                    -- begin nested --
-                    local ok = false
-                    if nstrigger and stack[nstrigger] then
-                        local outer = stack[attribute]
-                        if outer ~= inheritance then
-                            stack.leader, ok = process(namespace,attribute,leader,inheritance,outer)
-                        else
-                            stack.leader, ok = process(namespace,attribute,leader,inheritance,default)
-                        end
-                    else
-                        stack.leader, ok = process(namespace,attribute,leader,inheritance,default)
-                    end
-                    -- end nested --
-                    done = done or ok
-                    current = savedcurrent
-                    leader = false
-                end
-            elseif default and inheritance then
-                if current ~= default then
-                    head = insert_node_before(head,stack,copy_node(nsdata[default]))
-                    current = default
-                    done = true
-                end
-            elseif current > 0 then
-                head = insert_node_before(head,stack,copy_node(nsnone))
-                current = 0
-                done = true
-            end
-            check = false
-        end
-        stack = stack.next
-    end
-    return head, done
-end
-
-states.process = process
-
--- we can force a selector, e.g. document wide color spaces, saves a little
--- watch out, we need to check both the selector state (like colorspace) and
--- the main state (like color), otherwise we get into troubles when a selector
--- state changes while the main state stays the same (like two glyphs following
--- each other with the same color but different color spaces e.g. \showcolor)
-
--- local function selective(namespace,attribute,head,inheritance,default) -- two attributes
---     local stack, done = head, false
---     while stack do
---         local id = stack.id
---         -- we need to deal with literals too (reset as well as oval)
---         -- if id == glyph_code or (id == whatsit_code and stack.subtype == pdfliteral_code) or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then -- or disc_code
---         if id == glyph_code -- or id == disc_code
---                 or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then -- or disc_code
---             local c = stack[attribute]
---             if c then
---                 if default and c == inheritance then
---                     if current ~= default then
---                         local data = nsdata[default]
---                         head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
---                         current = default
---                         done = true
---                     end
---                 else
---                     local s = stack[nsselector]
---                     if current ~= c or current_selector ~= s then
---                         local data = nsdata[c]
---                         head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
---                         current = c
---                         current_selector = s
---                         done = true
---                     end
---                 end
---             elseif default and inheritance then
---                 if current ~= default then
---                     local data = nsdata[default]
---                     head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
---                     current = default
---                     done = true
---                 end
---             elseif current > 0 then
---                 head = insert_node_before(head,stack,copy_node(nsnone))
---                 current, current_selector, done = 0, 0, true
---             end
---             if id == glue_code then -- leader
---                 -- same as *list
---                 local content = stack.leader
---                 if content then
---                     local savedcurrent = current
---                     local ci = content.id
---                     if ci == hlist_code or ci == vlist_code then
---                         -- else we reset inside a box unneeded, okay, the downside is
---                         -- that we trigger color in each repeated box, so there is room
---                         -- for improvement here
---                         current = 0
---                     end
---                     local ok = false
---                     if nstrigger and stack[nstrigger] then
---                         local outer = stack[attribute]
---                         if outer ~= inheritance then
---                             stack.leader, ok = selective(namespace,attribute,content,inheritance,outer)
---                         else
---                             stack.leader, ok = selective(namespace,attribute,content,inheritance,default)
---                         end
---                     else
---                         stack.leader, ok = selective(namespace,attribute,content,inheritance,default)
---                     end
---                     current = savedcurrent
---                     done = done or ok
---                 end
---             end
---         elseif id == hlist_code or id == vlist_code then
---             local content = stack.list
---             if content then
---                 local ok = false
---                 if nstrigger and stack[nstrigger] then
---                     local outer = stack[attribute]
---                     if outer ~= inheritance then
---                         stack.list, ok = selective(namespace,attribute,content,inheritance,outer)
---                     else
---                         stack.list, ok = selective(namespace,attribute,content,inheritance,default)
---                     end
---                 else
---                     stack.list, ok = selective(namespace,attribute,content,inheritance,default)
---                 end
---                 done = done or ok
---             end
---         end
---         stack = stack.next
---     end
---     return head, done
--- end
-
--- local function selective(namespace,attribute,head,inheritance,default) -- two attributes
---     local stack, done = head, false
-
---     local function check()
---         local c = stack[attribute]
---         if c then
---             if default and c == inheritance then
---                 if current ~= default then
---                     local data = nsdata[default]
---                     head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
---                     current = default
---                     done = true
---                 end
---             else
---                 local s = stack[nsselector]
---                 if current ~= c or current_selector ~= s then
---                     local data = nsdata[c]
---                     head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
---                     current = c
---                     current_selector = s
---                     done = true
---                 end
---             end
---         elseif default and inheritance then
---             if current ~= default then
---                 local data = nsdata[default]
---                 head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
---                 current = default
---                 done = true
---             end
---         elseif current > 0 then
---             head = insert_node_before(head,stack,copy_node(nsnone))
---             current, current_selector, done = 0, 0, true
---         end
---         return c
---     end
-
---     local function nested(content)
---         if nstrigger and stack[nstrigger] then
---             local outer = stack[attribute]
---             if outer ~= inheritance then
---                 return selective(namespace,attribute,content,inheritance,outer)
---             else
---                 return selective(namespace,attribute,content,inheritance,default)
---             end
---         else
---             return selective(namespace,attribute,content,inheritance,default)
---         end
---     end
-
---     while stack do
---         local id = stack.id
---         if id == glyph_code then
---             check()
---         elseif id == glue_code then
---             local content = stack.leader
---             if content and check() then
---              -- local savedcurrent = current
---              -- local ci = content.id
---              -- if ci == hlist_code or ci == vlist_code then
---              --     -- else we reset inside a box unneeded, okay, the downside is
---              --     -- that we trigger color in each repeated box, so there is room
---              --     -- for improvement here
---              --     current = 0
---              -- end
-
---                 local ok = false
---                 stack.leader, ok = nested(content)
---                 done = done or ok
-
---              -- current = savedcurrent
---             end
---         elseif id == hlist_code or id == vlist_code then
---             local content = stack.list
---             if content then
-
---                 local ok = false
---                 stack.list, ok = nested(content)
---                 done = done or ok
-
---             end
---         elseif id == rule_code then
---             if stack.width ~= 0 then
---                 check()
---             end
---         end
---         stack = stack.next
---     end
---     return head, done
--- end
-
-local function selective(namespace,attribute,head,inheritance,default) -- two attributes
-    local stack  = head
-    local done   = false
-    local check  = false
-    local leader = nil
-    while stack do
-        local id = stack.id
-        if id == glyph_code then
-            check = true
-        elseif id == glue_code then
-            leader = stack.leader
-            if leader then
-                check = true
-            end
-        elseif id == hlist_code or id == vlist_code then
-            local content = stack.list
-            if content then
-                local ok = false
-                -- begin nested
-                if nstrigger and stack[nstrigger] then
-                    local outer = stack[attribute]
-                    if outer ~= inheritance then
-                        stack.list, ok = selective(namespace,attribute,content,inheritance,outer)
-                    else
-                        stack.list, ok = selective(namespace,attribute,content,inheritance,default)
-                    end
-                else
-                    stack.list, ok = selective(namespace,attribute,content,inheritance,default)
-                end
-                -- end nested
-                done = done or ok
-            end
-        elseif id == rule_code then
-            check = stack.width ~= 0
-        end
-
-        if check then
-            local c = stack[attribute]
-            if c then
-                if default and c == inheritance then
-                    if current ~= default then
-                        local data = nsdata[default]
-                        head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
-                        current = default
-                        done = true
-                    end
-                else
-                    local s = stack[nsselector]
-                    if current ~= c or current_selector ~= s then
-                        local data = nsdata[c]
-                        head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
-                        current = c
-                        current_selector = s
-                        done = true
-                    end
-                end
-                if leader then
-                    local ok = false
-                    -- begin nested
-                    if nstrigger and stack[nstrigger] then
-                        local outer = stack[attribute]
-                        if outer ~= inheritance then
-                            stack.leader, ok = selective(namespace,attribute,leader,inheritance,outer)
-                        else
-                            stack.leader, ok = selective(namespace,attribute,leader,inheritance,default)
-                        end
-                    else
-                        stack.leader, ok = selective(namespace,attribute,leader,inheritance,default)
-                    end
-                    -- end nested
-                    done = done or ok
-                    leader = false
-                end
-            elseif default and inheritance then
-                if current ~= default then
-                    local data = nsdata[default]
-                    head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
-                    current = default
-                    done = true
-                end
-            elseif current > 0 then
-                head = insert_node_before(head,stack,copy_node(nsnone))
-                current, current_selector, done = 0, 0, true
-            end
-            check = false
-        end
-
-        stack = stack.next
-    end
-    return head, done
-end
-
-states.selective = selective
-
--- Ideally the next one should be merged with the previous but keeping it separate is
--- safer. We deal with two situations: efficient boxwise (layoutareas) and mixed layers
--- (as used in the stepper). In the stepper we cannot use the box branch as it involves
--- paragraph lines and then gets mixed up. A messy business (esp since we want to be
--- efficient).
---
--- Todo: make a better stacker. Keep track (in attribute) about nesting level. Not
--- entirely trivial and a generic solution is nicer (compares to the exporter).
-
--- local function stacked(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
---     local stack, done = head, false
---     local current, depth = default or 0, 0
---
---     local function check()
---         local a = stack[attribute]
---         if a then
---             if current ~= a then
---                 head = insert_node_before(head,stack,copy_node(nsdata[a]))
---                 depth = depth + 1
---                 current, done = a, true
---             end
---         elseif default > 0 then
---             --
---         elseif current > 0 then
---             head = insert_node_before(head,stack,copy_node(nsnone))
---             depth = depth - 1
---             current, done = 0, true
---         end
---         return a
---     end
---
---     while stack do
---         local id = stack.id
---         if id == glyph_code then
---             check()
---         elseif id == glue_code then
---             local content = stack.leader
---             if content and check() then
---                 local ok = false
---                 stack.leader, ok = stacked(namespace,attribute,content,current)
---                 done = done or ok
---             end
---         elseif id == hlist_code or id == vlist_code then
---             local content = stack.list
---             if content then
---              -- the problem is that broken lines gets the attribute which can be a later one
---                 if nslistwise then
---                     local a = stack[attribute]
---                     if a and current ~= a and nslistwise[a] then -- viewerlayer / needs checking, see below
---                         local p = current
---                         current, done = a, true
---                         head = insert_node_before(head,stack,copy_node(nsdata[a]))
---                         stack.list = stacked(namespace,attribute,content,current)
---                         head, stack = insert_node_after(head,stack,copy_node(nsnone))
---                         current = p
---                     else
---                         local ok = false
---                         stack.list, ok = stacked(namespace,attribute,content,current)
---                         done = done or ok
---                     end
---                 else
---                     local ok = false
---                     stack.list, ok = stacked(namespace,attribute,content,current)
---                     done = done or ok
---                 end
---             end
---         elseif id == rule_code then
---             if stack.width ~= 0 then
---                 check()
---             end
---         end
---         stack = stack.next
---     end
---     while depth > 0 do
---         head = insert_node_after(head,stack,copy_node(nsnone))
---         depth = depth - 1
---     end
---     return head, done
--- end
-
-local function stacked(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
-    local stack   = head
-    local done    = false
-    local current = default or 0
-    local depth   = 0
-    local check   = false
-    local leader  = false
-    while stack do
-        local id = stack.id
-        if id == glyph_code then
-            check = true
-        elseif id == glue_code then
-            leader = stack.leader
-            if leader then
-                check = true
-            end
-        elseif id == hlist_code or id == vlist_code then
-            local content = stack.list
-            if content then
-             -- the problem is that broken lines gets the attribute which can be a later one
-                if nslistwise then
-                    local a = stack[attribute]
-                    if a and current ~= a and nslistwise[a] then -- viewerlayer / needs checking, see below
-                        local p = current
-                        current, done = a, true
-                        head = insert_node_before(head,stack,copy_node(nsdata[a]))
-                        stack.list = stacked(namespace,attribute,content,current)
-                        head, stack = insert_node_after(head,stack,copy_node(nsnone))
-                        current = p
-                    else
-                        local ok = false
-                        stack.list, ok = stacked(namespace,attribute,content,current)
-                        done = done or ok
-                    end
-                else
-                    local ok = false
-                    stack.list, ok = stacked(namespace,attribute,content,current)
-                    done = done or ok
-                end
-            end
-        elseif id == rule_code then
-            check = stack.width ~= 0
-        end
-
-        if check then
-            local a = stack[attribute]
-            if a then
-                if current ~= a then
-                    head = insert_node_before(head,stack,copy_node(nsdata[a]))
-                    depth = depth + 1
-                    current, done = a, true
-                end
-                if leader then
-                    local ok = false
-                    stack.leader, ok = stacked(namespace,attribute,content,current)
-                    done = done or ok
-                    leader = false
-                end
-            elseif default > 0 then
-                --
-            elseif current > 0 then
-                head = insert_node_before(head,stack,copy_node(nsnone))
-                depth = depth - 1
-                current, done = 0, true
-            end
-            check = false
-        end
-
-        stack = stack.next
-    end
-    while depth > 0 do
-        head = insert_node_after(head,stack,copy_node(nsnone))
-        depth = depth - 1
-    end
-    return head, done
-end
-
-states.stacked = stacked
-
--- experimental
-
--- local function stacker(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
---     nsbegin()
---     local current, previous, done, okay = head, head, false, false
---     local attrib = default or unsetvalue
---
---     local function check()
---         local a = current[attribute] or unsetvalue
---         if a ~= attrib then
---             local n = nsstep(a)
---             if n then
---              -- !!!! TEST CODE !!!!
---              -- head = insert_node_before(head,current,copy_node(nsdata[tonumber(n)])) -- a
---                 head = insert_node_before(head,current,n) -- a
---             end
---             attrib, done, okay = a, true, true
---         end
---         return a
---     end
---
---     while current do
---         local id = current.id
---         if id == glyph_code then
---             check()
---         elseif id == glue_code then
---             local content = current.leader
---             if content and check() then
---                 -- tricky as a leader has to be a list so we cannot inject before
---                 local _, ok = stacker(namespace,attribute,content,attrib)
---                 done = done or ok
---             end
---         elseif id == hlist_code or id == vlist_code then
---             local content = current.list
---             if not content then
---                 -- skip
---             elseif nslistwise then
---                 local a = current[attribute]
---                 if a and attrib ~= a and nslistwise[a] then -- viewerlayer
---                     done = true
---                     head = insert_node_before(head,current,copy_node(nsdata[a]))
---                     current.list = stacker(namespace,attribute,content,a)
---                     head, current = insert_node_after(head,current,copy_node(nsnone))
---                 else
---                     local ok = false
---                     current.list, ok = stacker(namespace,attribute,content,attrib)
---                     done = done or ok
---                 end
---             else
---                 local ok = false
---                 current.list, ok = stacker(namespace,attribute,content,default)
---                 done = done or ok
---             end
---         elseif id == rule_code then
---             if current.width ~= 0 then
---                 check()
---             end
---         end
---         previous = current
---         current = current.next
---     end
---     if okay then
---         local n = nsend()
---         if n then
---              -- !!!! TEST CODE !!!!
---          -- head = insert_node_after(head,previous,copy_node(nsdata[tostring(n)]))
---             head = insert_node_after(head,previous,n)
---         end
---     end
---     return head, done
--- end
-
-local function stacker(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
-    nsbegin()
-    local current  = head
-    local previous = head
-    local done     = false
-    local okay     = false
-    local attrib   = default or unsetvalue
-    local check    = false
-    local leader   = false
-    while current do
-        local id = current.id
-        if id == glyph_code then
-            check = true
-        elseif id == glue_code then
-            leader = current.leader
-            if leader then
-                check = true
-            end
-        elseif id == hlist_code or id == vlist_code then
-            local content = current.list
-            if not content then
-                -- skip
-            elseif nslistwise then
-                local a = current[attribute]
-                if a and attrib ~= a and nslistwise[a] then -- viewerlayer
-                    done = true
-                    head = insert_node_before(head,current,copy_node(nsdata[a]))
-                    current.list = stacker(namespace,attribute,content,a)
-                    head, current = insert_node_after(head,current,copy_node(nsnone))
-                else
-                    local ok = false
-                    current.list, ok = stacker(namespace,attribute,content,attrib)
-                    done = done or ok
-                end
-            else
-                local ok = false
-                current.list, ok = stacker(namespace,attribute,content,default)
-                done = done or ok
-            end
-        elseif id == rule_code then
-            check = current.width ~= 0
-        end
-
-        if check then
-            local a = current[attribute] or unsetvalue
-            if a ~= attrib then
-                local n = nsstep(a)
-                if n then
-                 -- !!!! TEST CODE !!!!
-                 -- head = insert_node_before(head,current,copy_node(nsdata[tonumber(n)])) -- a
-                    head = insert_node_before(head,current,n) -- a
-                end
-                attrib, done, okay = a, true, true
-                if leader then
-                    -- tricky as a leader has to be a list so we cannot inject before
-                    local _, ok = stacker(namespace,attribute,leader,attrib)
-                    done = done or ok
-                    leader = false
-                end
-            end
-            check = false
-        end
-
-        previous = current
-        current = current.next
-    end
-    if okay then
-        local n = nsend()
-        if n then
-             -- !!!! TEST CODE !!!!
-         -- head = insert_node_after(head,previous,copy_node(nsdata[tostring(n)]))
-            head = insert_node_after(head,previous,n)
-        end
-    end
-    return head, done
-end
-
-states.stacker = stacker
-
--- -- --
-
-statistics.register("attribute processing time", function()
-    return statistics.elapsedseconds(attributes,"front- and backend")
-end)
+if not modules then modules = { } end modules ['node-fin'] = {
+    version   = 1.001,
+    comment   = "companion to node-fin.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files",
+}
+
+-- this module is being reconstructed
+-- local functions, only slightly slower
+
+local next, type, format = next, type, string.format
+
+local attributes, nodes, node = attributes, nodes, node
+
+local copy_node       = node.copy
+local find_tail       = node.slide
+
+local nodecodes       = nodes.nodecodes
+local whatcodes       = nodes.whatcodes
+
+local glyph_code      = nodecodes.glyph
+local disc_code       = nodecodes.disc
+local glue_code       = nodecodes.glue
+local rule_code       = nodecodes.rule
+local whatsit_code    = nodecodes.whatsit
+local hlist_code      = nodecodes.hlist
+local vlist_code      = nodecodes.vlist
+
+local pdfliteral_code = whatcodes.pdfliteral
+
+local states          = attributes.states
+local numbers         = attributes.numbers
+local a_trigger       = attributes.private('trigger')
+local triggering      = false
+
+local starttiming     = statistics.starttiming
+local stoptiming      = statistics.stoptiming
+local loadstripped    = utilities.lua.loadstripped
+local unsetvalue      = attributes.unsetvalue
+
+-- these two will be like trackers
+
+function states.enabletriggering()
+    triggering = true
+end
+function states.disabletriggering()
+    triggering = false
+end
+
+-- the following code is no longer needed due to the new backend
+-- but we keep it around for a while as an example
+--
+-- states.collected = states.collected or { }
+--
+-- storage.register("states/collected", states.collected, "states.collected")
+--
+-- local collected = states.collected
+--
+-- function states.collect(str)
+--     collected[#collected+1] = str
+-- end
+--
+-- function states.flush()
+--     if #collected > 0 then
+--         for i=1,#collected do
+--             context(collected[i]) -- we're in context mode anyway
+--         end
+--         collected = { }
+--         states.collected = collected
+--     end
+-- end
+--
+-- function states.check()
+--     logs.report("states",concat(collected,"\n"))
+-- end
+
+-- we used to do the main processor loop here and call processor for each node
+-- but eventually this was too much a slow down (1 sec on 23 for 120 pages mk)
+-- so that we moved looping to the processor itself; this may lead to a bit of
+-- duplicate code once that we have more state handlers
+
+-- local function process_attribute(head,plugin) -- head,attribute,enabled,initializer,resolver,processor,finalizer
+--     local namespace = plugin.namespace
+--     if namespace.enabled ~= false then -- this test will go away
+--         starttiming(attributes) -- in principle we could delegate this to the main caller
+--         local done, used, ok = false, nil, false
+--         local attribute = namespace.attribute or numbers[plugin.name] -- todo: plugin.attribute
+--         local processor = plugin.processor
+--         if processor then
+--             local initializer = plugin.initializer
+--             local resolver    = plugin.resolver
+--             local inheritance = (resolver and resolver()) or nil -- -0x7FFFFFFF -- we can best use nil and skip !
+--             if initializer then
+--                 initializer(namespace,attribute,head)
+--             end
+--             head, ok = processor(namespace,attribute,head,inheritance)
+--             if ok then
+--                 local finalizer = plugin.finalizer
+--                 if finalizer then
+--                     head, ok, used = finalizer(namespace,attribute,head)
+--                     if used then
+--                         local flusher = plugin.flusher
+--                         if flusher then
+--                             head = flusher(namespace,attribute,head,used)
+--                         end
+--                     end
+--                 end
+--                 done = true
+--             end
+--         end
+--         stoptiming(attributes)
+--         return head, done
+--     else
+--         return head, false
+--     end
+-- end
+--
+-- function nodes.installattributehandler(plugin) -- we need to avoid this nested function
+--     return function(head)
+--         return process_attribute(head,plugin)
+--     end
+-- end
+
+-- An experiment: lean and mean functions. It is not really faster but
+-- with upcoming functionality it might make a difference, e.g. features
+-- like 'casing' and 'italics' can be called a lot so there it makes sense.
+
+nodes.plugindata = nil
+
+local template = [[
+local plugin = nodes.plugindata
+local starttiming = statistics.starttiming
+local stoptiming = statistics.stoptiming
+local namespace = plugin.namespace
+local attribute = namespace.attribute or attributes.numbers[plugin.name]
+local processor = plugin.processor
+local initializer = plugin.initializer
+local resolver = plugin.resolver
+local finalizer = plugin.finalizer
+local flusher = plugin.flusher
+if not processor then
+    return function(head)
+        return head, false
+    end
+elseif initializer or finalizer or resolver then
+    return function(head)
+        starttiming(attributes)
+        local done, used, ok = false, nil, false
+        local inheritance = (resolver and resolver()) or nil -- -0x7FFFFFFF -- we can best use nil and skip !
+        if initializer then
+            initializer(namespace,attribute,head)
+        end
+        head, ok = processor(namespace,attribute,head,inheritance)
+        if ok then
+            if finalizer then
+                head, ok, used = finalizer(namespace,attribute,head)
+                if used and flusher then
+                    head = flusher(namespace,attribute,head,used)
+                end
+            end
+            done = true
+        end
+        stoptiming(attributes)
+        return head, done
+    end
+else
+    return function(head)
+        starttiming(attributes)
+        local head, done = processor(namespace,attribute,head)
+        stoptiming(attributes)
+        return head, done
+    end
+end
+nodes.plugindata = nil
+]]
+
+function nodes.installattributehandler(plugin)
+    nodes.plugindata = plugin
+    return loadstripped(template)()
+end
+
+-- the injectors
+
+local insert_node_before = node.insert_before
+local insert_node_after  = node.insert_after
+
+local nsdata, nsnone, nslistwise, nsforced, nsselector, nstrigger
+local current, current_selector, done = 0, 0, false -- nb, stack has a local current !
+local nsbegin, nsend
+
+function states.initialize(namespace,attribute,head)
+    nsdata           = namespace.data
+    nsnone           = namespace.none
+    nsforced         = namespace.forced
+    nsselector       = namespace.selector
+    nslistwise       = namespace.listwise
+    nstrigger        = triggering and namespace.triggering and a_trigger
+    current          = 0
+    current_selector = 0
+    done             = false -- todo: done cleanup
+    nsstep           = namespace.resolve_step
+    if nsstep then
+        nsbegin      = namespace.resolve_begin
+        nsend        = namespace.resolve_end
+        nspush       = namespace.push
+        nspop        = namespace.pop
+    end
+end
+
+function states.finalize(namespace,attribute,head) -- is this one ok?
+    if current > 0 and nsnone then
+        local id = head.id
+        if id == hlist_code or id == vlist_code then
+            local list = head.list
+            if list then
+                head.list = insert_node_before(list,list,copy_node(nsnone))
+            end
+        else
+            head = insert_node_before(head,head,copy_node(nsnone))
+        end
+        return head, true, true
+    end
+    return head, false, false
+end
+
+-- disc nodes can be ignored
+-- we need to deal with literals too (reset as well as oval)
+-- if id == glyph_code or (id == whatsit_code and stack.subtype == pdfliteral_code) or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then
+
+-- local function process(namespace,attribute,head,inheritance,default) -- one attribute
+--     local stack, done = head, false
+--     while stack do
+--         local id = stack.id
+--         if id == glyph_code or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then -- or disc_code
+--             local c = stack[attribute]
+--             if c then
+--                 if default and c == inheritance then
+--                     if current ~= default then
+--                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                         current = default
+--                         done = true
+--                     end
+--                 elseif current ~= c then
+--                     head = insert_node_before(head,stack,copy_node(nsdata[c]))
+--                     current = c
+--                     done = true
+--                 end
+--                 -- here ? compare selective
+--                 if id == glue_code then --leader
+--                     -- same as *list
+--                     local content = stack.leader
+--                     if content then
+--                         local savedcurrent = current
+--                         local ci = content.id
+--                         if ci == hlist_code or ci == vlist_code then
+--                             -- else we reset inside a box unneeded, okay, the downside is
+--                             -- that we trigger color in each repeated box, so there is room
+--                             -- for improvement here
+--                             current = 0
+--                         end
+--                         local ok = false
+--                         if nstrigger and stack[nstrigger] then
+--                             local outer = stack[attribute]
+--                             if outer ~= inheritance then
+--                                 stack.leader, ok = process(namespace,attribute,content,inheritance,outer)
+--                             else
+--                                 stack.leader, ok = process(namespace,attribute,content,inheritance,default)
+--                             end
+--                         else
+--                             stack.leader, ok = process(namespace,attribute,content,inheritance,default)
+--                         end
+--                         current = savedcurrent
+--                         done = done or ok
+--                     end
+--                 end
+--             elseif default and inheritance then
+--                 if current ~= default then
+--                     head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                     current = default
+--                     done = true
+--                 end
+--             elseif current > 0 then
+--                 head = insert_node_before(head,stack,copy_node(nsnone))
+--                 current = 0
+--                 done = true
+--             end
+--         elseif id == hlist_code or id == vlist_code then
+--             local content = stack.list
+--             if content then
+--                 local ok = false
+--                 if nstrigger and stack[nstrigger] then
+--                     local outer = stack[attribute]
+--                     if outer ~= inheritance then
+--                         stack.list, ok = process(namespace,attribute,content,inheritance,outer)
+--                     else
+--                         stack.list, ok = process(namespace,attribute,content,inheritance,default)
+--                     end
+--                 else
+--                     stack.list, ok = process(namespace,attribute,content,inheritance,default)
+--                 end
+--                 done = done or ok
+--             end
+--         end
+--         stack = stack.next
+--     end
+--     return head, done
+-- end
+
+-- local function process(namespace,attribute,head,inheritance,default) -- one attribute
+--     local stack, done = head, false
+
+--     local function check()
+--         local c = stack[attribute]
+--         if c then
+--             if default and c == inheritance then
+--                 if current ~= default then
+--                     head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                     current = default
+--                     done = true
+--                 end
+--             elseif current ~= c then
+--                 head = insert_node_before(head,stack,copy_node(nsdata[c]))
+--                 current = c
+--                 done = true
+--             end
+--         elseif default and inheritance then
+--             if current ~= default then
+--                 head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                 current = default
+--                 done = true
+--             end
+--         elseif current > 0 then
+--             head = insert_node_before(head,stack,copy_node(nsnone))
+--             current = 0
+--             done = true
+--         end
+--         return c
+--     end
+
+--     local function nested(content)
+--         if nstrigger and stack[nstrigger] then
+--             local outer = stack[attribute]
+--             if outer ~= inheritance then
+--                 return process(namespace,attribute,content,inheritance,outer)
+--             else
+--                 return process(namespace,attribute,content,inheritance,default)
+--             end
+--         else
+--             return process(namespace,attribute,content,inheritance,default)
+--         end
+--     end
+
+--     while stack do
+--         local id = stack.id
+--         if id == glyph_code then
+--             check()
+--         elseif id == glue_code then
+--             local content = stack.leader
+--             if content and check() then
+--                 local savedcurrent = current
+--                 local ci = content.id
+--                 if ci == hlist_code or ci == vlist_code then
+--                     -- else we reset inside a box unneeded, okay, the downside is
+--                     -- that we trigger color in each repeated box, so there is room
+--                     -- for improvement here
+--                     current = 0
+--                 end
+
+--                 local ok = false
+--                 stack.leader, ok = nested(content)
+--                 done = done or ok
+
+--                 current = savedcurrent
+--             end
+--         elseif id == hlist_code or id == vlist_code then
+--             local content = stack.list
+--             if content then
+
+--                 local ok = false
+--                 stack.list, ok = nested(content)
+--                 done = done or ok
+
+--             end
+--         elseif id == rule_code then
+--             if stack.width ~= 0 then
+--                 check()
+--             end
+--         end
+--         stack = stack.next
+--     end
+--     return head, done
+-- end
+
+-- local function process(namespace,attribute,head,inheritance,default) -- one attribute
+--     local stack, done = head, false
+--     while stack do
+--         local id = stack.id
+--         if id == glyph_code then
+--             -- begin of check
+--             local c = stack[attribute]
+--             if c then
+--                 if default and c == inheritance then
+--                     if current ~= default then
+--                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                         current = default
+--                         done = true
+--                     end
+--                 elseif current ~= c then
+--                     head = insert_node_before(head,stack,copy_node(nsdata[c]))
+--                     current = c
+--                     done = true
+--                 end
+--             elseif default and inheritance then
+--                 if current ~= default then
+--                     head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                     current = default
+--                     done = true
+--                 end
+--             elseif current > 0 then
+--                 head = insert_node_before(head,stack,copy_node(nsnone))
+--                 current = 0
+--                 done = true
+--             end
+--             -- end of check
+--         elseif id == glue_code then
+--             local content = stack.leader
+--             if content then
+--                 -- begin of check
+--                 local c = stack[attribute]
+--                 if c then
+--                     if default and c == inheritance then
+--                         if current ~= default then
+--                             head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                             current = default
+--                             done = true
+--                         end
+--                     elseif current ~= c then
+--                         head = insert_node_before(head,stack,copy_node(nsdata[c]))
+--                         current = c
+--                         done = true
+--                     end
+--                     -- begin special to this check
+--                     local savedcurrent = current
+--                     local ci = content.id
+--                     if ci == hlist_code or ci == vlist_code then
+--                         -- else we reset inside a box unneeded, okay, the downside is
+--                         -- that we trigger color in each repeated box, so there is room
+--                         -- for improvement here
+--                         current = 0
+--                     end
+--                     -- begin nested --
+--                     local ok = false
+--                     if nstrigger and stack[nstrigger] then
+--                         local outer = stack[attribute]
+--                         if outer ~= inheritance then
+--                             stack.leader, ok = process(namespace,attribute,content,inheritance,outer)
+--                         else
+--                             stack.leader, ok = process(namespace,attribute,content,inheritance,default)
+--                         end
+--                     else
+--                         stack.leader, ok = process(namespace,attribute,content,inheritance,default)
+--                     end
+--                     -- end nested --
+--                     done = done or ok
+--                     current = savedcurrent
+--                     -- end special to this check
+--                 elseif default and inheritance then
+--                     if current ~= default then
+--                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                         current = default
+--                         done = true
+--                     end
+--                 elseif current > 0 then
+--                     head = insert_node_before(head,stack,copy_node(nsnone))
+--                     current = 0
+--                     done = true
+--                 end
+--                 -- end of check
+--             end
+--         elseif id == hlist_code or id == vlist_code then
+--             local content = stack.list
+--             if content then
+--                 -- begin nested --
+--                 local ok
+--                 if nstrigger and stack[nstrigger] then
+--                     local outer = stack[attribute]
+--                     if outer ~= inheritance then
+--                         stack.list, ok = process(namespace,attribute,content,inheritance,outer)
+--                     else
+--                         stack.list, ok = process(namespace,attribute,content,inheritance,default)
+--                     end
+--                 else
+--                     stack.list, ok = process(namespace,attribute,content,inheritance,default)
+--                 end
+--                 -- end nested --
+--                 done = done or ok
+--             end
+--         elseif id == rule_code then
+--             if stack.width ~= 0 then
+--                 -- begin of check
+--                 local c = stack[attribute]
+--                 if c then
+--                     if default and c == inheritance then
+--                         if current ~= default then
+--                             head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                             current = default
+--                             done = true
+--                         end
+--                     elseif current ~= c then
+--                         head = insert_node_before(head,stack,copy_node(nsdata[c]))
+--                         current = c
+--                         done = true
+--                     end
+--                 elseif default and inheritance then
+--                     if current ~= default then
+--                         head = insert_node_before(head,stack,copy_node(nsdata[default]))
+--                         current = default
+--                         done = true
+--                     end
+--                 elseif current > 0 then
+--                     head = insert_node_before(head,stack,copy_node(nsnone))
+--                     current = 0
+--                     done = true
+--                 end
+--                 -- end of check
+--             end
+--         end
+--         stack = stack.next
+--     end
+--     return head, done
+-- end
+
+local function process(namespace,attribute,head,inheritance,default) -- one attribute
+    local stack  = head
+    local done   = false
+    local check  = false
+    local leader = nil
+    while stack do
+        local id = stack.id
+        if id == glyph_code then
+            check = true
+        elseif id == glue_code then
+            leader = stack.leader
+            if leader then
+                check = true
+            end
+        elseif id == hlist_code or id == vlist_code then
+            local content = stack.list
+            if content then
+                -- begin nested --
+                local ok
+                if nstrigger and stack[nstrigger] then
+                    local outer = stack[attribute]
+                    if outer ~= inheritance then
+                        stack.list, ok = process(namespace,attribute,content,inheritance,outer)
+                    else
+                        stack.list, ok = process(namespace,attribute,content,inheritance,default)
+                    end
+                else
+                    stack.list, ok = process(namespace,attribute,content,inheritance,default)
+                end
+                -- end nested --
+                done = done or ok
+            end
+        elseif id == rule_code then
+            check = stack.width ~= 0
+        end
+        -- much faster this way than using a check() and nested() function
+        if check then
+            local c = stack[attribute]
+            if c then
+                if default and c == inheritance then
+                    if current ~= default then
+                        head = insert_node_before(head,stack,copy_node(nsdata[default]))
+                        current = default
+                        done = true
+                    end
+                elseif current ~= c then
+                    head = insert_node_before(head,stack,copy_node(nsdata[c]))
+                    current = c
+                    done = true
+                end
+                if leader then
+                    local savedcurrent = current
+                    local ci = leader.id
+                    if ci == hlist_code or ci == vlist_code then
+                        -- else we reset inside a box unneeded, okay, the downside is
+                        -- that we trigger color in each repeated box, so there is room
+                        -- for improvement here
+                        current = 0
+                    end
+                    -- begin nested --
+                    local ok = false
+                    if nstrigger and stack[nstrigger] then
+                        local outer = stack[attribute]
+                        if outer ~= inheritance then
+                            stack.leader, ok = process(namespace,attribute,leader,inheritance,outer)
+                        else
+                            stack.leader, ok = process(namespace,attribute,leader,inheritance,default)
+                        end
+                    else
+                        stack.leader, ok = process(namespace,attribute,leader,inheritance,default)
+                    end
+                    -- end nested --
+                    done = done or ok
+                    current = savedcurrent
+                    leader = false
+                end
+            elseif default and inheritance then
+                if current ~= default then
+                    head = insert_node_before(head,stack,copy_node(nsdata[default]))
+                    current = default
+                    done = true
+                end
+            elseif current > 0 then
+                head = insert_node_before(head,stack,copy_node(nsnone))
+                current = 0
+                done = true
+            end
+            check = false
+        end
+        stack = stack.next
+    end
+    return head, done
+end
+
+states.process = process
+
+-- we can force a selector, e.g. document wide color spaces, saves a little
+-- watch out, we need to check both the selector state (like colorspace) and
+-- the main state (like color), otherwise we get into troubles when a selector
+-- state changes while the main state stays the same (like two glyphs following
+-- each other with the same color but different color spaces e.g. \showcolor)
+
+-- local function selective(namespace,attribute,head,inheritance,default) -- two attributes
+--     local stack, done = head, false
+--     while stack do
+--         local id = stack.id
+--         -- we need to deal with literals too (reset as well as oval)
+--         -- if id == glyph_code or (id == whatsit_code and stack.subtype == pdfliteral_code) or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then -- or disc_code
+--         if id == glyph_code -- or id == disc_code
+--                 or (id == rule_code and stack.width ~= 0) or (id == glue_code and stack.leader) then -- or disc_code
+--             local c = stack[attribute]
+--             if c then
+--                 if default and c == inheritance then
+--                     if current ~= default then
+--                         local data = nsdata[default]
+--                         head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+--                         current = default
+--                         done = true
+--                     end
+--                 else
+--                     local s = stack[nsselector]
+--                     if current ~= c or current_selector ~= s then
+--                         local data = nsdata[c]
+--                         head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+--                         current = c
+--                         current_selector = s
+--                         done = true
+--                     end
+--                 end
+--             elseif default and inheritance then
+--                 if current ~= default then
+--                     local data = nsdata[default]
+--                     head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+--                     current = default
+--                     done = true
+--                 end
+--             elseif current > 0 then
+--                 head = insert_node_before(head,stack,copy_node(nsnone))
+--                 current, current_selector, done = 0, 0, true
+--             end
+--             if id == glue_code then -- leader
+--                 -- same as *list
+--                 local content = stack.leader
+--                 if content then
+--                     local savedcurrent = current
+--                     local ci = content.id
+--                     if ci == hlist_code or ci == vlist_code then
+--                         -- else we reset inside a box unneeded, okay, the downside is
+--                         -- that we trigger color in each repeated box, so there is room
+--                         -- for improvement here
+--                         current = 0
+--                     end
+--                     local ok = false
+--                     if nstrigger and stack[nstrigger] then
+--                         local outer = stack[attribute]
+--                         if outer ~= inheritance then
+--                             stack.leader, ok = selective(namespace,attribute,content,inheritance,outer)
+--                         else
+--                             stack.leader, ok = selective(namespace,attribute,content,inheritance,default)
+--                         end
+--                     else
+--                         stack.leader, ok = selective(namespace,attribute,content,inheritance,default)
+--                     end
+--                     current = savedcurrent
+--                     done = done or ok
+--                 end
+--             end
+--         elseif id == hlist_code or id == vlist_code then
+--             local content = stack.list
+--             if content then
+--                 local ok = false
+--                 if nstrigger and stack[nstrigger] then
+--                     local outer = stack[attribute]
+--                     if outer ~= inheritance then
+--                         stack.list, ok = selective(namespace,attribute,content,inheritance,outer)
+--                     else
+--                         stack.list, ok = selective(namespace,attribute,content,inheritance,default)
+--                     end
+--                 else
+--                     stack.list, ok = selective(namespace,attribute,content,inheritance,default)
+--                 end
+--                 done = done or ok
+--             end
+--         end
+--         stack = stack.next
+--     end
+--     return head, done
+-- end
+
+-- local function selective(namespace,attribute,head,inheritance,default) -- two attributes
+--     local stack, done = head, false
+
+--     local function check()
+--         local c = stack[attribute]
+--         if c then
+--             if default and c == inheritance then
+--                 if current ~= default then
+--                     local data = nsdata[default]
+--                     head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+--                     current = default
+--                     done = true
+--                 end
+--             else
+--                 local s = stack[nsselector]
+--                 if current ~= c or current_selector ~= s then
+--                     local data = nsdata[c]
+--                     head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+--                     current = c
+--                     current_selector = s
+--                     done = true
+--                 end
+--             end
+--         elseif default and inheritance then
+--             if current ~= default then
+--                 local data = nsdata[default]
+--                 head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+--                 current = default
+--                 done = true
+--             end
+--         elseif current > 0 then
+--             head = insert_node_before(head,stack,copy_node(nsnone))
+--             current, current_selector, done = 0, 0, true
+--         end
+--         return c
+--     end
+
+--     local function nested(content)
+--         if nstrigger and stack[nstrigger] then
+--             local outer = stack[attribute]
+--             if outer ~= inheritance then
+--                 return selective(namespace,attribute,content,inheritance,outer)
+--             else
+--                 return selective(namespace,attribute,content,inheritance,default)
+--             end
+--         else
+--             return selective(namespace,attribute,content,inheritance,default)
+--         end
+--     end
+
+--     while stack do
+--         local id = stack.id
+--         if id == glyph_code then
+--             check()
+--         elseif id == glue_code then
+--             local content = stack.leader
+--             if content and check() then
+--              -- local savedcurrent = current
+--              -- local ci = content.id
+--              -- if ci == hlist_code or ci == vlist_code then
+--              --     -- else we reset inside a box unneeded, okay, the downside is
+--              --     -- that we trigger color in each repeated box, so there is room
+--              --     -- for improvement here
+--              --     current = 0
+--              -- end
+
+--                 local ok = false
+--                 stack.leader, ok = nested(content)
+--                 done = done or ok
+
+--              -- current = savedcurrent
+--             end
+--         elseif id == hlist_code or id == vlist_code then
+--             local content = stack.list
+--             if content then
+
+--                 local ok = false
+--                 stack.list, ok = nested(content)
+--                 done = done or ok
+
+--             end
+--         elseif id == rule_code then
+--             if stack.width ~= 0 then
+--                 check()
+--             end
+--         end
+--         stack = stack.next
+--     end
+--     return head, done
+-- end
+
+local function selective(namespace,attribute,head,inheritance,default) -- two attributes
+    local stack  = head
+    local done   = false
+    local check  = false
+    local leader = nil
+    while stack do
+        local id = stack.id
+        if id == glyph_code then
+            check = true
+        elseif id == glue_code then
+            leader = stack.leader
+            if leader then
+                check = true
+            end
+        elseif id == hlist_code or id == vlist_code then
+            local content = stack.list
+            if content then
+                local ok = false
+                -- begin nested
+                if nstrigger and stack[nstrigger] then
+                    local outer = stack[attribute]
+                    if outer ~= inheritance then
+                        stack.list, ok = selective(namespace,attribute,content,inheritance,outer)
+                    else
+                        stack.list, ok = selective(namespace,attribute,content,inheritance,default)
+                    end
+                else
+                    stack.list, ok = selective(namespace,attribute,content,inheritance,default)
+                end
+                -- end nested
+                done = done or ok
+            end
+        elseif id == rule_code then
+            check = stack.width ~= 0
+        end
+
+        if check then
+            local c = stack[attribute]
+            if c then
+                if default and c == inheritance then
+                    if current ~= default then
+                        local data = nsdata[default]
+                        head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+                        current = default
+                        done = true
+                    end
+                else
+                    local s = stack[nsselector]
+                    if current ~= c or current_selector ~= s then
+                        local data = nsdata[c]
+                        head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+                        current = c
+                        current_selector = s
+                        done = true
+                    end
+                end
+                if leader then
+                    local ok = false
+                    -- begin nested
+                    if nstrigger and stack[nstrigger] then
+                        local outer = stack[attribute]
+                        if outer ~= inheritance then
+                            stack.leader, ok = selective(namespace,attribute,leader,inheritance,outer)
+                        else
+                            stack.leader, ok = selective(namespace,attribute,leader,inheritance,default)
+                        end
+                    else
+                        stack.leader, ok = selective(namespace,attribute,leader,inheritance,default)
+                    end
+                    -- end nested
+                    done = done or ok
+                    leader = false
+                end
+            elseif default and inheritance then
+                if current ~= default then
+                    local data = nsdata[default]
+                    head = insert_node_before(head,stack,copy_node(data[nsforced or stack[nsselector] or nsselector]))
+                    current = default
+                    done = true
+                end
+            elseif current > 0 then
+                head = insert_node_before(head,stack,copy_node(nsnone))
+                current, current_selector, done = 0, 0, true
+            end
+            check = false
+        end
+
+        stack = stack.next
+    end
+    return head, done
+end
+
+states.selective = selective
+
+-- Ideally the next one should be merged with the previous but keeping it separate is
+-- safer. We deal with two situations: efficient boxwise (layoutareas) and mixed layers
+-- (as used in the stepper). In the stepper we cannot use the box branch as it involves
+-- paragraph lines and then gets mixed up. A messy business (esp since we want to be
+-- efficient).
+--
+-- Todo: make a better stacker. Keep track (in attribute) about nesting level. Not
+-- entirely trivial and a generic solution is nicer (compares to the exporter).
+
+-- local function stacked(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
+--     local stack, done = head, false
+--     local current, depth = default or 0, 0
+--
+--     local function check()
+--         local a = stack[attribute]
+--         if a then
+--             if current ~= a then
+--                 head = insert_node_before(head,stack,copy_node(nsdata[a]))
+--                 depth = depth + 1
+--                 current, done = a, true
+--             end
+--         elseif default > 0 then
+--             --
+--         elseif current > 0 then
+--             head = insert_node_before(head,stack,copy_node(nsnone))
+--             depth = depth - 1
+--             current, done = 0, true
+--         end
+--         return a
+--     end
+--
+--     while stack do
+--         local id = stack.id
+--         if id == glyph_code then
+--             check()
+--         elseif id == glue_code then
+--             local content = stack.leader
+--             if content and check() then
+--                 local ok = false
+--                 stack.leader, ok = stacked(namespace,attribute,content,current)
+--                 done = done or ok
+--             end
+--         elseif id == hlist_code or id == vlist_code then
+--             local content = stack.list
+--             if content then
+--              -- the problem is that broken lines gets the attribute which can be a later one
+--                 if nslistwise then
+--                     local a = stack[attribute]
+--                     if a and current ~= a and nslistwise[a] then -- viewerlayer / needs checking, see below
+--                         local p = current
+--                         current, done = a, true
+--                         head = insert_node_before(head,stack,copy_node(nsdata[a]))
+--                         stack.list = stacked(namespace,attribute,content,current)
+--                         head, stack = insert_node_after(head,stack,copy_node(nsnone))
+--                         current = p
+--                     else
+--                         local ok = false
+--                         stack.list, ok = stacked(namespace,attribute,content,current)
+--                         done = done or ok
+--                     end
+--                 else
+--                     local ok = false
+--                     stack.list, ok = stacked(namespace,attribute,content,current)
+--                     done = done or ok
+--                 end
+--             end
+--         elseif id == rule_code then
+--             if stack.width ~= 0 then
+--                 check()
+--             end
+--         end
+--         stack = stack.next
+--     end
+--     while depth > 0 do
+--         head = insert_node_after(head,stack,copy_node(nsnone))
+--         depth = depth - 1
+--     end
+--     return head, done
+-- end
+
+local function stacked(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
+    local stack   = head
+    local done    = false
+    local current = default or 0
+    local depth   = 0
+    local check   = false
+    local leader  = false
+    while stack do
+        local id = stack.id
+        if id == glyph_code then
+            check = true
+        elseif id == glue_code then
+            leader = stack.leader
+            if leader then
+                check = true
+            end
+        elseif id == hlist_code or id == vlist_code then
+            local content = stack.list
+            if content then
+             -- the problem is that broken lines gets the attribute which can be a later one
+                if nslistwise then
+                    local a = stack[attribute]
+                    if a and current ~= a and nslistwise[a] then -- viewerlayer / needs checking, see below
+                        local p = current
+                        current, done = a, true
+                        head = insert_node_before(head,stack,copy_node(nsdata[a]))
+                        stack.list = stacked(namespace,attribute,content,current)
+                        head, stack = insert_node_after(head,stack,copy_node(nsnone))
+                        current = p
+                    else
+                        local ok = false
+                        stack.list, ok = stacked(namespace,attribute,content,current)
+                        done = done or ok
+                    end
+                else
+                    local ok = false
+                    stack.list, ok = stacked(namespace,attribute,content,current)
+                    done = done or ok
+                end
+            end
+        elseif id == rule_code then
+            check = stack.width ~= 0
+        end
+
+        if check then
+            local a = stack[attribute]
+            if a then
+                if current ~= a then
+                    head = insert_node_before(head,stack,copy_node(nsdata[a]))
+                    depth = depth + 1
+                    current, done = a, true
+                end
+                if leader then
+                    local ok = false
+                    stack.leader, ok = stacked(namespace,attribute,content,current)
+                    done = done or ok
+                    leader = false
+                end
+            elseif default > 0 then
+                --
+            elseif current > 0 then
+                head = insert_node_before(head,stack,copy_node(nsnone))
+                depth = depth - 1
+                current, done = 0, true
+            end
+            check = false
+        end
+
+        stack = stack.next
+    end
+    while depth > 0 do
+        head = insert_node_after(head,stack,copy_node(nsnone))
+        depth = depth - 1
+    end
+    return head, done
+end
+
+states.stacked = stacked
+
+-- experimental
+
+-- local function stacker(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
+--     nsbegin()
+--     local current, previous, done, okay = head, head, false, false
+--     local attrib = default or unsetvalue
+--
+--     local function check()
+--         local a = current[attribute] or unsetvalue
+--         if a ~= attrib then
+--             local n = nsstep(a)
+--             if n then
+--              -- !!!! TEST CODE !!!!
+--              -- head = insert_node_before(head,current,copy_node(nsdata[tonumber(n)])) -- a
+--                 head = insert_node_before(head,current,n) -- a
+--             end
+--             attrib, done, okay = a, true, true
+--         end
+--         return a
+--     end
+--
+--     while current do
+--         local id = current.id
+--         if id == glyph_code then
+--             check()
+--         elseif id == glue_code then
+--             local content = current.leader
+--             if content and check() then
+--                 -- tricky as a leader has to be a list so we cannot inject before
+--                 local _, ok = stacker(namespace,attribute,content,attrib)
+--                 done = done or ok
+--             end
+--         elseif id == hlist_code or id == vlist_code then
+--             local content = current.list
+--             if not content then
+--                 -- skip
+--             elseif nslistwise then
+--                 local a = current[attribute]
+--                 if a and attrib ~= a and nslistwise[a] then -- viewerlayer
+--                     done = true
+--                     head = insert_node_before(head,current,copy_node(nsdata[a]))
+--                     current.list = stacker(namespace,attribute,content,a)
+--                     head, current = insert_node_after(head,current,copy_node(nsnone))
+--                 else
+--                     local ok = false
+--                     current.list, ok = stacker(namespace,attribute,content,attrib)
+--                     done = done or ok
+--                 end
+--             else
+--                 local ok = false
+--                 current.list, ok = stacker(namespace,attribute,content,default)
+--                 done = done or ok
+--             end
+--         elseif id == rule_code then
+--             if current.width ~= 0 then
+--                 check()
+--             end
+--         end
+--         previous = current
+--         current = current.next
+--     end
+--     if okay then
+--         local n = nsend()
+--         if n then
+--              -- !!!! TEST CODE !!!!
+--          -- head = insert_node_after(head,previous,copy_node(nsdata[tostring(n)]))
+--             head = insert_node_after(head,previous,n)
+--         end
+--     end
+--     return head, done
+-- end
+
+local function stacker(namespace,attribute,head,default) -- no triggering, no inheritance, but list-wise
+    nsbegin()
+    local current  = head
+    local previous = head
+    local done     = false
+    local okay     = false
+    local attrib   = default or unsetvalue
+    local check    = false
+    local leader   = false
+    while current do
+        local id = current.id
+        if id == glyph_code then
+            check = true
+        elseif id == glue_code then
+            leader = current.leader
+            if leader then
+                check = true
+            end
+        elseif id == hlist_code or id == vlist_code then
+            local content = current.list
+            if not content then
+                -- skip
+            elseif nslistwise then
+                local a = current[attribute]
+                if a and attrib ~= a and nslistwise[a] then -- viewerlayer
+                    done = true
+                    head = insert_node_before(head,current,copy_node(nsdata[a]))
+                    current.list = stacker(namespace,attribute,content,a)
+                    head, current = insert_node_after(head,current,copy_node(nsnone))
+                else
+                    local ok = false
+                    current.list, ok = stacker(namespace,attribute,content,attrib)
+                    done = done or ok
+                end
+            else
+                local ok = false
+                current.list, ok = stacker(namespace,attribute,content,default)
+                done = done or ok
+            end
+        elseif id == rule_code then
+            check = current.width ~= 0
+        end
+
+        if check then
+            local a = current[attribute] or unsetvalue
+            if a ~= attrib then
+                local n = nsstep(a)
+                if n then
+                 -- !!!! TEST CODE !!!!
+                 -- head = insert_node_before(head,current,copy_node(nsdata[tonumber(n)])) -- a
+                    head = insert_node_before(head,current,n) -- a
+                end
+                attrib, done, okay = a, true, true
+                if leader then
+                    -- tricky as a leader has to be a list so we cannot inject before
+                    local _, ok = stacker(namespace,attribute,leader,attrib)
+                    done = done or ok
+                    leader = false
+                end
+            end
+            check = false
+        end
+
+        previous = current
+        current = current.next
+    end
+    if okay then
+        local n = nsend()
+        if n then
+             -- !!!! TEST CODE !!!!
+         -- head = insert_node_after(head,previous,copy_node(nsdata[tostring(n)]))
+            head = insert_node_after(head,previous,n)
+        end
+    end
+    return head, done
+end
+
+states.stacker = stacker
+
+-- -- --
+
+statistics.register("attribute processing time", function()
+    return statistics.elapsedseconds(attributes,"front- and backend")
+end)