beta 2013.09.09 11:46

1 files changed, 474 insertions, 0 deletions

diff --git a/tex/context/base/typo-dha.lua b/tex/context/base/typo-dha.lua
new file mode 100644
index 000000000..35dfa856e
--- /dev/null
+++ b/tex/context/base/typo-dha.lua
@@ -0,0 +1,474 @@
+if not modules then modules = { } end modules ['typo-dha'] = {
+    version   = 1.001,
+    comment   = "companion to typo-dir.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- Some analysis by Idris:
+--
+-- 1. Assuming the reading- vs word-order distinction (bidi-char types) is governing;
+-- 2. Assuming that 'ARAB' represents an actual arabic string in raw input order, not word-order;
+-- 3. Assuming that 'BARA' represent the correct RL word order;
+--
+-- Then we have, with input: LATIN ARAB
+--
+-- \textdir TLT LATIN ARAB => LATIN BARA
+-- \textdir TRT LATIN ARAB => LATIN BARA
+-- \textdir TRT LRO LATIN ARAB => LATIN ARAB
+-- \textdir TLT LRO LATIN ARAB => LATIN ARAB
+-- \textdir TLT RLO LATIN ARAB => NITAL ARAB
+-- \textdir TRT RLO LATIN ARAB => NITAL ARAB
+
+-- elseif d == "es"  then -- European Number Separator
+-- elseif d == "et"  then -- European Number Terminator
+-- elseif d == "cs"  then -- Common Number Separator
+-- elseif d == "nsm" then -- Non-Spacing Mark
+-- elseif d == "bn"  then -- Boundary Neutral
+-- elseif d == "b"   then -- Paragraph Separator
+-- elseif d == "s"   then -- Segment Separator
+-- elseif d == "ws"  then -- Whitespace
+-- elseif d == "on"  then -- Other Neutrals
+
+-- todo  : delayed inserts here
+-- todo  : get rid of local functions here
+-- beware: math adds whatsits afterwards so that will mess things up
+-- todo  : use new dir functions
+-- todo  : make faster
+-- todo  : move dir info into nodes
+-- todo  : swappable tables and floats i.e. start-end overloads (probably loop in builders)
+-- todo  : check if we still have crashes in luatex when non-matched (used to be the case)
+
+local nodes, node = nodes, node
+
+local trace_directions   = false  trackers.register("typesetters.directions.default", function(v) trace_directions = v end)
+
+local report_directions  = logs.reporter("typesetting","text directions")
+
+local hasbit             = number.hasbit
+local formatters         = string.formatters
+local insert             = table.insert
+
+local insert_node_before = nodes.insert_before
+local insert_node_after  = nodes.insert_after
+local remove_node        = nodes.remove
+local end_of_math        = nodes.end_of_math
+
+local nodecodes          = nodes.nodecodes
+local whatcodes          = nodes.whatcodes
+local mathcodes          = nodes.mathcodes
+
+local glyph_code         = nodecodes.glyph
+local whatsit_code       = nodecodes.whatsit
+local math_code          = nodecodes.math
+local penalty_code       = nodecodes.penalty
+local kern_code          = nodecodes.kern
+local glue_code          = nodecodes.glue
+local hlist_code         = nodecodes.hlist
+local vlist_code         = nodecodes.vlist
+
+local localpar_code      = whatcodes.localpar
+local dir_code           = whatcodes.dir
+
+local nodepool           = nodes.pool
+
+local new_textdir        = nodepool.textdir
+
+local fonthashes         = fonts.hashes
+local fontdata           = fonthashes.identifiers
+local fontchar           = fonthashes.characters
+
+local chardirections     = characters.directions
+local charmirrors        = characters.mirrors
+local charclasses        = characters.textclasses
+
+local directions         = typesetters.directions
+local getglobal          = directions.getglobal
+
+local a_state            = attributes.private('state')
+local a_directions       = attributes.private('directions')
+
+local strip              = false
+
+local s_isol             = fonts.analyzers.states.isol
+
+local function process(namespace,attribute,start)
+
+    local head = start
+
+    local current, inserted = head, nil
+    local finish, autodir, embedded, override, done = nil, 0, 0, 0, false
+    local list, glyphs = trace_directions and { }, false
+    local finished, finidir, finipos = nil, nil, 1
+    local stack, top, obsolete = { }, 0, { }
+    local lro, rlo, prevattr = false, false, 0
+
+    local function finish_auto_before()
+        local fdir = finish == "TRT" and "-TRT" or "-TLT"
+        head, inserted = insert_node_before(head,current,new_textdir(fdir))
+        finished, finidir, autodir = inserted, finish, 0
+        if trace_directions then
+            insert(list,#list,formatters["auto %a inserted before, autodir %a, embedded %a"](fdir,autodir,embedded))
+            finipos = #list - 1
+        end
+        finish, done = nil, true
+    end
+
+    local function finish_auto_after()
+        local fdir = finish == "TRT" and "-TRT" or "-TLT"
+        head, current = insert_node_after(head,current,new_textdir(fdir))
+        finished, finidir, autodir = current, finish, 0
+        if trace_directions then
+            list[#list+1] = formatters["auto %a inserted after, autodir %a, embedded %a"](fdir,autodir,embedded)
+            finipos = #list
+        end
+        finish, done = nil, true
+    end
+
+    local function force_auto_left_before(d)
+        if finish then
+            finish_auto_before()
+        end
+        if embedded >= 0 then
+            finish, autodir = "TLT",  1
+        else
+            finish, autodir = "TRT", -1
+        end
+        done = true
+        if finidir == finish then
+            head = remove_node(head,finished,true)
+            if trace_directions then
+                list[finipos] = list[finipos] .. ", deleted afterwards"
+                insert(list,#list,formatters["start text dir %a, auto left before, embedded %a, autodir %a, triggered by class %a"](finish,embedded,autodir,d))
+            end
+        else
+            head, inserted = insert_node_before(head,current,new_textdir("+"..finish))
+            if trace_directions then
+                insert(list,#list,formatters["start text dir %a, auto left before, embedded %a, autodir %a, triggered by class %a"](finish,embedded,autodir,d))
+            end
+        end
+    end
+
+    local function force_auto_right_before(d)
+        if finish then
+            finish_auto_before()
+        end
+        if embedded <= 0 then
+            finish, autodir, done = "TRT", -1
+        else
+            finish, autodir, done = "TLT",  1
+        end
+        done = true
+        if finidir == finish then
+            head = remove_node(head,finished,true)
+            if trace_directions then
+                list[finipos] = list[finipos] .. ", deleted afterwards"
+                insert(list,#list,formatters["start text dir %a, auto right before, embedded %a, autodir %a, triggered by class %a"](finish,embedded,autodir,d))
+            end
+        else
+            head, inserted = insert_node_before(head,current,new_textdir("+"..finish))
+            if trace_directions then
+                insert(list,#list,formatters["start text dir %a, auto right before, embedded %a, autodir %a, triggered by class %a"](finish,embedded,autodir,d))
+            end
+        end
+    end
+
+    local function nextisright(current)
+     -- repeat
+            current = current.next
+            local id = current.id
+            if id == glyph_code then
+                local char = current.char
+                local d = chardirections[char]
+                return d == "r" or d == "al" or d == "an"
+         -- elseif id == glue_code or id == kern_code or id == penalty_code then
+         --   -- too complex
+     --     else
+     --         return
+            end
+     -- until not current
+    end
+
+    local function previsright(current)
+     -- repeat
+            current = current.prev
+            local id = current.id
+            if id == glyph_code then
+                local char = current.char
+                local d = chardirections[char]
+                return d == "r" or d == "al" or d == "an"
+         -- elseif id == glue_code or id == kern_code or id == penalty_code then
+         --     -- too complex
+     --     else
+     --         return
+            end
+     -- until not current
+    end
+
+    while current do
+        local id = current.id
+     -- list[#list+1] = formatters["state: node %a, finish %a, autodir %a, embedded %a"](nutstring(current),finish or "unset",autodir,embedded)
+        if id == math_code then
+            current = end_of_math(current.next).next
+        else
+            local attr = current[attribute]
+            if attr and attr > 0 and attr ~= prevattr then
+                if getglobal(a) then
+                    -- bidi parsing mode
+                else
+                    -- local
+                    if trace_directions and
+                        current ~= head then list[#list+1] = formatters["override reset, bidi %a"](attr)
+                    end
+                    lro, rlo = false, false
+                end
+                prevattr = attr
+            end
+         -- if attr and attr > 0 then
+         --     if attr == 1 then
+         --         -- bidi parsing mode
+         --     elseif attr ~= prevattr then
+         --         -- no pop, grouped driven (2=normal,3=lro,4=rlo)
+         --         if attr == 3 then
+         --             if trace_directions then
+         --                 list[#list+1] = formatters["override right -> left (lro), bidi %a"](attr)
+         --             end
+         --             lro, rlo = true, false
+         --         elseif attr == 4 then
+         --             if trace_directions then
+         --                 list[#list+1] = formatters["override left -> right (rlo), bidi %a"](attr)
+         --             end
+         --             lro, rlo = false, true
+         --         else
+         --             if trace_directions and
+         --                 current ~= head then list[#list+1] = formatters["override reset, bidi %a"](attr)
+         --             end
+         --             lro, rlo = false, false
+         --         end
+         --         prevattr = attr
+         --     end
+         -- end
+            if id == glyph_code then
+                glyphs = true
+                if attr and attr > 0 then
+                    local char = current.char
+                    local d = chardirections[char]
+                    if rlo or override > 0 then
+                        if d == "l" then
+                            if trace_directions then
+                                list[#list+1] = formatters["char %C of class %a overridden to r, bidi %a)"](char,d,attr)
+                            end
+                            d = "r"
+                        elseif trace_directions then
+                            if d == "lro" or d == "rlo" or d == "pdf" then -- else side effects on terminal
+                                list[#list+1] = formatters["override char of class %a, bidi %a"](d,attr)
+                            else -- todo: rle lre
+                                list[#list+1] = formatters["char %C of class %a, bidi %a"](char,d,attr)
+                            end
+                        end
+                    elseif lro or override < 0 then
+                        if d == "r" or d == "al" then
+                            current[a_state] = s_isol -- maybe better have a special bidi attr value -> override (9) -> todo
+                            if trace_directions then
+                                list[#list+1] = formatters["char %C of class %a overridden to l, bidi %a, state 'isol'"](char,d,attr)
+                            end
+                            d = "l"
+                        elseif trace_directions then
+                            if d == "lro" or d == "rlo" or d == "pdf" then -- else side effects on terminal
+                                list[#list+1] = formatters["override char of class %a, bidi %a"](d,attr)
+                            else -- todo: rle lre
+                                list[#list+1] = formatters["char %C of class %a, bidi %a"](char,d,attr)
+                            end
+                        end
+                    elseif trace_directions then
+                        if d == "lro" or d == "rlo" or d == "pdf" then -- else side effects on terminal
+                            list[#list+1] = formatters["override char of class %a, bidi %a"](d,attr)
+                        else -- todo: rle lre
+                            list[#list+1] = formatters["char %C of class %a, bidi %a"](char,d,attr)
+                        end
+                    end
+                    if d == "on" then
+                        local mirror = charmirrors[char]
+                        if mirror and fontchar[current.font][mirror] then
+                            -- todo: set attribute
+                            local class = charclasses[char]
+                            if class == "open" then
+                                if nextisright(current) then
+                                    if autodir >= 0 then
+                                        force_auto_right_before(d)
+                                    end
+                                    current.char = mirror
+                                    done = true
+                                else
+                                    mirror = nil
+                                    if autodir <= 0 then
+                                        force_auto_left_before(d)
+                                    end
+                                end
+                            elseif class == "close" then
+                                if previsright(current) then
+                                    current.char = mirror
+                                    done = true
+                                else
+                                    mirror = nil
+                                end
+                            elseif autodir < 0 then
+                                current.char = mirror
+                                done = true
+                            else
+                                mirror = nil
+                            end
+                            if trace_directions then
+                                if mirror then
+                                    list[#list+1] = formatters["mirroring char %C of class %a to %C, autodir %a, bidi %a"](char,d,mirror,autodir,attr)
+                                else
+                                    list[#list+1] = formatters["not mirroring char %C of class %a, autodir %a, bidi %a"](char,d,autodir,attr)
+                                end
+                            end
+                        end
+                    elseif d == "l" or d == "en" then -- european number
+                        if autodir <= 0 then -- could be option
+                            force_auto_left_before(d)
+                        end
+                    elseif d == "r" or d == "al" then -- arabic number
+                        if autodir >= 0 then
+                            force_auto_right_before(d)
+                        end
+                    elseif d == "an" then -- arabic number
+                        -- actually this is language dependent ...
+                     -- if autodir <= 0 then
+                     --     force_auto_left_before(d)
+                     -- end
+                        if autodir >= 0 then
+                            force_auto_right_before(d)
+                        end
+                    elseif d == "lro" then -- Left-to-Right Override -> right becomes left
+                        if trace_directions then
+                            list[#list+1] = "override right -> left"
+                        end
+                        top = top + 1
+                        stack[top] = { override, embedded }
+                        override = -1
+                        obsolete[#obsolete+1] = current
+                    elseif d == "rlo" then -- Right-to-Left Override -> left becomes right
+                        if trace_directions then
+                            list[#list+1] = "override left -> right"
+                        end
+                        top = top + 1
+                        stack[top] = { override, embedded }
+                        override = 1
+                        obsolete[#obsolete+1] = current
+                    elseif d == "lre" then -- Left-to-Right Embedding -> TLT
+                        if trace_directions then
+                            list[#list+1] = "embedding left -> right"
+                        end
+                        top = top + 1
+                        stack[top] = { override, embedded }
+                        embedded = 1
+                        obsolete[#obsolete+1] = current
+                    elseif d == "rle" then -- Right-to-Left Embedding -> TRT
+                        if trace_directions then
+                            list[#list+1] = "embedding right -> left"
+                        end
+                        top = top + 1
+                        stack[top] = { override, embedded }
+                        embedded = -1 -- was 1
+                        obsolete[#obsolete+1] = current
+                    elseif d == "pdf" then -- Pop Directional Format
+                     -- override = 0
+                        if top > 0 then
+                            local s = stack[top]
+                            override, embedded = s[1], s[2]
+                            top = top - 1
+                            if trace_directions then
+                                list[#list+1] = formatters["state: override %a, embedded %a, autodir %a"](override,embedded,autodir)
+                            end
+                        else
+                            if trace_directions then
+                                list[#list+1] = "pop error: too many pops"
+                            end
+                        end
+                        obsolete[#obsolete+1] = current
+                    end
+                elseif trace_directions then
+                    local char = current.char
+                    local d = chardirections[char]
+                    list[#list+1] = formatters["char %C of class %a, bidi %a"](char,d or "?")
+                end
+            elseif id == whatsit_code then
+                -- we have less directions now so we can do hard checks for strings instead of splitting into pieces
+                if finish then
+                    finish_auto_before()
+                end
+                local subtype = current.subtype
+                if subtype == localpar_code then
+                 -- if false then
+                        local dir = current.dir
+                        if dir == 'TRT' then
+                            autodir = -1
+                        elseif dir == 'TLT' then
+                            autodir = 1
+                        end
+                    -- embedded = autodir
+                        if trace_directions then
+                            list[#list+1] = formatters["pardir %a"](dir)
+                        end
+                 -- end
+                elseif subtype == dir_code then
+                    local dir = current.dir
+                    if dir == "+TRT" then
+                        finish, autodir = "TRT", -1
+                    elseif dir == "-TRT" then
+                        finish, autodir = nil, 0
+                    elseif dir == "+TLT" then
+                        finish, autodir = "TLT", 1
+                    elseif dir == "-TLT" then
+                        finish, autodir = nil, 0
+                    end
+                    if trace_directions then
+                        list[#list+1] = formatters["textdir %a, autodir %a"](dir,autodir)
+                    end
+                end
+            else
+                if trace_directions then
+                    list[#list+1] = formatters["node %a, subtype %a"](nodecodes[id],current.subtype)
+                end
+                if finish then
+                    finish_auto_before()
+                end
+            end
+            local cn = current.next
+            if not cn then
+                if finish then
+                    finish_auto_after()
+                end
+            end
+            current = cn
+        end
+    end
+
+    if trace_directions and glyphs then
+        report_directions("start log")
+        for i=1,#list do
+            report_directions("%02i: %s",i,list[i])
+        end
+        report_directions("stop log")
+    end
+
+    if done and strip then
+        local n = #obsolete
+        if n > 0 then
+            for i=1,n do
+                remove_node(head,obsolete[i],true)
+            end
+            report_directions("%s character nodes removed",n)
+        end
+    end
+
+    return head, done
+
+end
+
+directions.installhandler(interfaces.variables.default,process)
+