1 files changed, 136 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/node-tst.lua b/tex/context/base/mkiv/node-tst.lua
new file mode 100644
index 000000000..4832c048c
--- /dev/null
+++ b/tex/context/base/mkiv/node-tst.lua
@@ -0,0 +1,136 @@
+if not modules then modules = { } end modules ['node-tst'] = {
+    version   = 1.001,
+    comment   = "companion to node-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local nodes, node = nodes, node
+
+local chardata                   = characters.data
+local nodecodes                  = nodes.nodecodes
+local skipcodes                  = nodes.skipcodes
+
+local glue_code                  = nodecodes.glue
+local penalty_code               = nodecodes.penalty
+local kern_code                  = nodecodes.kern
+local glyph_code                 = nodecodes.glyph
+local whatsit_code               = nodecodes.whatsit
+local hlist_code                 = nodecodes.hlist
+
+local leftskip_code              = skipcodes.leftskip
+local rightskip_code             = skipcodes.rightskip
+local abovedisplayshortskip_code = skipcodes.abovedisplayshortskip
+local belowdisplayshortskip_code = skipcodes.belowdisplayshortskip
+
+local nuts                       = nodes.nuts
+
+local getfield                   = nuts.getfield
+local getnext                    = nuts.getnext
+local getprev                    = nuts.getprev
+local getid                      = nuts.getid
+local getchar                    = nuts.getchar
+local getsubtype                 = nuts.getsubtype
+
+local find_node_tail             = nuts.tail
+
+function nuts.leftmarginwidth(n) -- todo: three values
+    while n do
+        local id = getid(n)
+        if id == glue_code then
+            return getsubtype(n) == leftskip_code and getfield(n,"width") or 0
+        elseif id == whatsit_code then
+            n = getnext(n)
+        elseif id == hlist_code then
+            return getfield(n,"width")
+        else
+            break
+        end
+    end
+    return 0
+end
+
+function nuts.rightmarginwidth(n)
+    if n then
+        n = find_node_tail(n)
+        while n do
+            local id = getid(n)
+            if id == glue_code then
+                return getsubtype(n) == rightskip_code and getfield(n,"width") or 0
+            elseif id == whatsit_code then
+                n = getprev(n)
+            else
+                break
+            end
+        end
+    end
+    return false
+end
+
+function nuts.somespace(n,all)
+    if n then
+        local id = getid(n)
+        if id == glue_code then
+            return (all or ((getfield(n,"width") or 0) ~= 0)) and glue_code -- temp: or 0
+         -- return (all or (getfield(n,"width") ~= 0)) and glue_code
+        elseif id == kern_code then
+            return (all or (getfield(n,"kern") ~= 0)) and kern
+        elseif id == glyph_code then
+            local category = chardata[getchar(n)].category
+         -- maybe more category checks are needed
+            return (category == "zs") and glyph_code
+        end
+    end
+    return false
+end
+
+function nuts.somepenalty(n,value)
+    if n then
+        local id = getid(n)
+        if id == penalty_code then
+            if value then
+                return getfield(n,"penalty") == value
+            else
+                return true
+            end
+        end
+    end
+    return false
+end
+
+function nuts.is_display_math(head)
+    local n = getprev(head)
+    while n do
+        local id = getid(n)
+        if id == penalty_code then
+        elseif id == glue_code then
+            if getsubtype(n) == abovedisplayshortskip_code then
+                return true
+            end
+        else
+            break
+        end
+        n = getprev(n)
+    end
+    n = getnext(head)
+    while n do
+        local id = getid(n)
+        if id == penalty_code then
+        elseif id == glue_code then
+            if getsubtype(n) == belowdisplayshortskip_code then
+                return true
+            end
+        else
+            break
+        end
+        n = getnext(n)
+    end
+    return false
+end
+
+nodes.leftmarginwidth  = nodes.vianuts(nuts.leftmarginwidth)
+nodes.rightmarginwidth = nodes.vianuts(nuts.rightmarginwidth)
+nodes.somespace        = nodes.vianuts(nuts.somespace)
+nodes.somepenalty      = nodes.vianuts(nuts.somepenalty)
+nodes.is_display_math  = nodes.vianuts(nuts.is_display_math)