1 files changed, 53 insertions, 22 deletions

diff --git a/tex/context/base/node-par.lua b/tex/context/base/node-par.lua
index ee0dfaf8a..a8ad969fe 100644
--- a/tex/context/base/node-par.lua
+++ b/tex/context/base/node-par.lua
@@ -9,54 +9,85 @@ if not modules then modules = { } end modules ['node-par'] = {
 parbuilders              = parbuilders or { }
 parbuilders.constructors = parbuilders.constructors or { }
 parbuilders.names        = parbuilders.names or { }
+parbuilders.numbers      = parbuilders.numbers or { }
 parbuilders.attribute    = attributes.numbers['parbuilder'] or 999
 
-local constructors, names, p_attribute = parbuilders.constructors, parbuilders.names, parbuilders.attribute
+storage.register("parbuilders.names",   parbuilders.names,   "parbuilders.names")
+storage.register("parbuilders.numbers", parbuilders.numbers, "parbuilders.numbers")
 
-storage.register("parbuilders.names", parbuilders.names, "parbuilders.names")
+local constructors, names, numbers, p_attribute = parbuilders.constructors, parbuilders.names, parbuilders.numbers, parbuilders.attribute
 
 local has_attribute = node.has_attribute
 local starttiming, stoptiming = statistics.starttiming, statistics.stoptiming
 
--- store parbuilders.names
+local mainconstructor = nil -- not stored in format
 
-function parbuilders.register(name,attribute)
-    parbuilders.names[attribute] = name
+function parbuilders.register(name,number)
+    parbuilders.names[number] = name
+    parbuilders.numbers[name] = number
 end
 
-function parbuilders.constructor(head,is_display)
-    local attribute = has_attribute(head,p_attribute)
-    if attribute then
-        local constructor = names[attribute]
-        if constructor then
-            return constructors[constructor](head,is_display)
+function parbuilders.setmain(name)
+    mainconstructor = numbers[name]
+end
+
+-- return values:
+--
+-- true  : tex will break itself
+-- false : idem but dangerous
+-- head  : list of valid vmode nodes with last being hlist
+
+function parbuilders.constructor(head,followed_by_display)
+    if type(head) == "boolean" then
+        return head
+    else
+        local attribute = has_attribute(head,p_attribute) or mainconstructor
+        if attribute then
+            local constructor = names[attribute]
+            if constructor then
+                return constructors[constructor](head,followed_by_display)
+            end
         end
+        return true -- let tex break
     end
-    return false
 end
 
 -- just for testing
 
-function parbuilders.constructors.default(head,is_display)
-    return false
+function parbuilders.constructors.default(head,followed_by_display)
+    return true -- let tex break
 end
 
 -- also for testing (no surrounding spacing done)
 
-function parbuilders.constructors.oneline(head,is_display)
+function parbuilders.constructors.oneline(head,followed_by_display)
     return node.hpack(head)
 end
 
-local actions = tasks.actions("parbuilders",1)
+-- It makes no sense to have a sequence here as we already have
+-- pre and post hooks and only one parbuilder makes sense, so no:
+--
+-- local actions = tasks.actions("parbuilders",1)
+
+-- todo: enable one as main
 
-local function processor(head,is_display)
-    starttiming(parbuilders)
-    local _, done = actions(head,is_display)
-    stoptiming(parbuilders)
-    return done
+local actions = parbuilders.constructor
+local enabled = false
+
+function parbuilders.enable () enabled = true  end
+function parbuilders.disable() enabled = false end
+
+local function processor(head,followed_by_display)
+    if enabled then
+        starttiming(parbuilders)
+        local head = actions(head,followed_by_display)
+        stoptiming(parbuilders)
+        return head
+    else
+        return true -- ler tex do the work
+    end
 end
 
---~ callbacks.register('linebreak_filter', actions, "breaking paragraps into lines")
 callbacks.register('linebreak_filter', processor, "breaking paragraps into lines")
 
 statistics.register("linebreak processing time", function()