stable 2010.07.30 11:35

1 files changed, 247 insertions, 0 deletions

diff --git a/tex/context/base/math-tag.lua b/tex/context/base/math-tag.lua
new file mode 100644
index 000000000..7180435f5
--- /dev/null
+++ b/tex/context/base/math-tag.lua
@@ -0,0 +1,247 @@
+if not modules then modules = { } end modules ['math-tag'] = {
+    version   = 1.001,
+    comment   = "companion to math-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local has_attribute  = nodes.has_attribute
+local set_attribute  = nodes.set_attribute
+local set_attributes = nodes.set_attributes
+
+local traverse_nodes = node.traverse
+
+local math_noad      = node.id("noad")           -- attr nucleus sub sup
+local math_noad      = node.id("noad")           -- attr nucleus sub sup
+local math_accent    = node.id("accent")         -- attr nucleus sub sup accent
+local math_radical   = node.id("radical")        -- attr nucleus sub sup left degree
+local math_fraction  = node.id("fraction")       -- attr nucleus sub sup left right
+local math_box       = node.id("sub_box")        -- attr list
+local math_sub       = node.id("sub_mlist")      -- attr list
+local math_char      = node.id("math_char")      -- attr fam char
+local math_text_char = node.id("math_text_char") -- attr fam char
+local math_delim     = node.id("delim")          -- attr small_fam small_char large_fam large_char
+local math_style     = node.id("style")          -- attr style
+local math_choice    = node.id("choice")         -- attr display text script scriptscript
+local math_fence     = node.id("fence")          -- attr subtype
+
+local hlist          = node.id("hlist")
+local vlist          = node.id("vlist")
+local glyph          = node.id("glyph")
+
+local a_tagged = attributes.private('tagged')
+
+local start_tagged = structure.tags.start
+local stop_tagged  = structure.tags.stop
+local chardata     = characters.data
+
+local process
+
+local function processsubsup(start)
+    local nucleus, sup, sub = start.nucleus, start.sup, start.sub
+    if sub then
+        if sup then
+            set_attribute(start,a_tagged,start_tagged("msubsup"))
+            process(nucleus)
+            process(sup)
+            process(sub)
+            stop_tagged()
+        else
+            set_attribute(start,a_tagged,start_tagged("msub"))
+            process(nucleus)
+            process(sub)
+            stop_tagged()
+        end
+    elseif sup then
+        set_attribute(start,a_tagged,start_tagged("msup"))
+        process(nucleus)
+        process(sup)
+        stop_tagged()
+    else
+        process(nucleus)
+    end
+end
+
+process = function(start) -- we cannot use the processor as we have no finalizers (yet)
+    while start do
+        local id = start.id
+        if id == math_char then
+            -- check for code
+            local ch = chardata[start.char]
+            local mc = ch and ch.mathclass
+            if mc == "number" then
+                set_attribute(start,a_tagged,start_tagged("mn"))
+            elseif mc == "variable" or not mc then -- variable is default
+                set_attribute(start,a_tagged,start_tagged("mi"))
+            else
+                set_attribute(start,a_tagged,start_tagged("mo"))
+            end
+            stop_tagged()
+            break
+        elseif id == math_text_char then
+            -- check for code
+            set_attribute(start,a_tagged,start_tagged("ms"))
+            stop_tagged()
+            break
+        elseif id == math_delim then
+            -- check for code
+            set_attribute(start,a_tagged,start_tagged("mo"))
+            stop_tagged()
+            break
+        elseif id == math_style then
+            -- has a next
+        elseif id == math_noad then
+            processsubsup(start)
+        elseif id == math_box or id == hlist or id == vlist then
+            -- keep an eye on math_box and see what ends up in there
+            local attr = has_attribute(start,a_tagged)
+            local text = start_tagged("mtext")
+            set_attribute(start,a_tagged,text)
+            local list = start.list
+            if not list then
+                -- empty list
+            elseif not attr then
+                -- box comes from strange place
+                set_attributes(list,a_tagged,text)
+            else
+                -- Beware, the first node in list is the actual list so we definitely
+                -- need to nest. This approach is a hack, maybe I'll make a proper
+                -- nesting feature to deal with this at another level. Here we just
+                -- fake structure by enforcing the inner one.
+                local taglist = structure.tags.taglist
+                local tagdata = taglist[attr]
+                local common = #tagdata + 1
+                local function runner(list) -- quite inefficient
+                    local cache = { } -- we can have nested unboxed mess so best local to runner
+                    for n in traverse_nodes(list) do
+                        local id = n.id
+                        if id == hlist or id == vlist then
+                            runner(n.list)
+                        elseif id == glyph then
+                            local aa = has_attribute(n,a_tagged) -- only glyph needed
+                            if aa then
+                                local ac = cache[aa]
+                                if not ac then
+                                    local tagdata = taglist[aa]
+                                    local extra = #tagdata
+                                    if common <= extra then
+                                        for i=common,extra do
+                                            ac = start_tagged(tagdata[i]) -- can be made faster
+                                        end
+                                        for i=common,extra do
+                                            stop_tagged() -- can be made faster
+                                        end
+                                    else
+                                        ac = text
+                                    end
+                                    cache[aa] = ac
+                                end
+                                set_attribute(n,a_tagged,ac)
+                            else
+                                set_attribute(n,a_tagged,text)
+                            end
+                        end
+                    end
+                end
+                runner(list)
+            end
+            stop_tagged()
+        elseif id == math_sub then
+            local list = start.list
+            if list then
+                set_attribute(start,a_tagged,start_tagged("mrow"))
+                process(list)
+                stop_tagged()
+            end
+        elseif id == math_fraction then
+            local num, denom, left, right = start.num, start.denom, start.left, start.right
+            if left then
+               set_attribute(left,a_tagged,start_tagged("mo"))
+               process(left)
+               stop_tagged()
+            end
+            set_attribute(start,a_tagged,start_tagged("mfrac"))
+            process(num)
+            process(denom)
+            stop_tagged()
+            if right then
+                set_attribute(right,a_tagged,start_tagged("mo"))
+                process(right)
+                stop_tagged()
+            end
+        elseif id == math_choice then
+            local display, text, script, scriptscript = start.display, start.text, start.script, start.scriptscript
+            if display then
+                process(display)
+            end
+            if text then
+                process(text)
+            end
+            if script then
+                process(script)
+            end
+            if scriptscript then
+                process(scriptscript)
+            end
+        elseif id == math_fence then
+            local delim = start.delim
+            if delim then
+                set_attribute(start,a_tagged,start_tagged("mo"))
+                process(delim)
+                stop_tagged()
+            end
+        elseif id == math_radical then
+            local left, degree = start.left, start.degree
+            if left then
+                process(left) -- mrow needed ?
+            end
+            if degree then
+                set_attribute(start,a_tagged,start_tagged("mroot"))
+                processsubsup(start)
+                process(degree)
+                stop_tagged()
+            else
+                set_attribute(start,a_tagged,start_tagged("msqrt"))
+                processsubsup(start)
+                stop_tagged()
+            end
+        elseif id == math_accent then
+            local accent, bot_accent = start.accent, start.bot_accent
+            if bot_accent then
+                if accent then
+                    set_attribute(start,a_tagged,start_tagged("munderover"))
+                    process(accent)
+                    processsubsup(start)
+                    process(bot_accent)
+                    stop_tagged()
+                else
+                    set_attribute(start,a_tagged,start_tagged("munder"))
+                    processsubsup(start)
+                    process(bot_accent)
+                    stop_tagged()
+                end
+            elseif accent then
+                set_attribute(start,a_tagged,start_tagged("mover"))
+                process(accent)
+                processsubsup(start)
+                stop_tagged()
+            else
+                processsubsup(start)
+            end
+        else
+            set_attribute(start,a_tagged,start_tagged("merror"))
+            stop_tagged()
+        end
+        start = start.next
+    end
+end
+
+function noads.add_tags(head,style,penalties)
+    set_attribute(head,a_tagged,start_tagged("math"))
+    set_attribute(head,a_tagged,start_tagged("mrow"))
+    process(head)
+    stop_tagged()
+    stop_tagged()
+    return true
+end