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|
if not modules then modules = { } end modules ['char-utf'] = {
version = 1.001,
comment = "companion to char-utf.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
--[[ldx--
<p>When a sequence of <l n='utf'/> characters enters the application, it may be
neccessary to collapse subsequences into their composed variant.</p>
<p>This module implements methods for collapsing and expanding <l n='utf'/>
sequences. We also provide means to deal with characters that are special to
<l n='tex'/> as well as 8-bit characters that need to end up in special kinds
of output (for instance <l n='pdf'/>).</p>
<p>We implement these manipulations as filters. One can run multiple filters
over a string.</p>
<p>The old code has now been moved to char-obs.lua which we keep around for
educational purposes.</p>
--ldx]]--
local next, type = next, type
local gsub, find = string.gsub, string.find
local concat, sortedhash, keys, sort = table.concat, table.sortedhash, table.keys, table.sort
local utfchar, utfbyte, utfcharacters, utfvalues = utf.char, utf.byte, utf.characters, utf.values
local P, Cs, Cmt, Ct = lpeg.P, lpeg.Cs, lpeg.Cmt, lpeg.Ct
if not characters then require("char-def") end
if not characters.blocks then require("char-ini") end
local lpegmatch = lpeg.match
local lpegpatterns = lpeg.patterns
local p_utf8character = lpegpatterns.utf8character
local p_utf8byte = lpegpatterns.utf8byte
local utfchartabletopattern = lpeg.utfchartabletopattern
local formatters = string.formatters
local allocate = utilities.storage.allocate or function() return { } end
local mark = utilities.storage.mark or allocate
local charfromnumber = characters.fromnumber
characters = characters or { }
local characters = characters
local filters = allocate()
characters.filters = filters
local utffilters = { }
characters.filters.utf = utffilters
local data = characters.data
--[[ldx--
<p>It only makes sense to collapse at runtime, since we don't expect source code
to depend on collapsing.</p>
--ldx]]--
-- for the moment, will be entries in char-def.lua .. this is just a subset that for
-- typographic (font) reasons we want to have split ... if we decompose all, we get
-- problems with fonts
local decomposed = allocate {
["IJ"] = "IJ",
["ij"] = "ij",
["և"] = "եւ",
["ff"] = "ff",
["fi"] = "fi",
["fl"] = "fl",
["ffi"] = "ffi",
["ffl"] = "ffl",
["ſt"] = "ſt",
["st"] = "st",
["ﬓ"] = "մն",
["ﬔ"] = "մե",
["ﬕ"] = "մի",
["ﬖ"] = "վն",
["ﬗ"] = "մխ",
}
characters.decomposed = decomposed
local graphemes = characters.graphemes
local collapsed = characters.collapsed
local mathlists = characters.mathlists
if graphemes then
mark(graphemes)
mark(collapsed)
mark(mathlists)
else
graphemes = allocate()
collapsed = allocate()
mathlists = allocate()
characters.graphemes = graphemes
characters.collapsed = collapsed
characters.mathlists = mathlists
local function backtrack(v,last,target)
local vs = v.specials
if vs and #vs == 3 and vs[1] == "char" then
local one, two = vs[2], vs[3]
local first, second = utfchar(one), utfchar(two) .. last
collapsed[first..second] = target
backtrack(data[one],second,target)
end
end
local function setlist(unicode,list,start,category)
if list[start] ~= 0x20 then
local t = mathlists
for i=start,#list do
local l = list[i]
local f = t[l]
if f then
t = f
else
f = { }
t[l] = f
t = f
end
end
t[category] = unicode
end
end
local mlists = { }
for unicode, v in next, data do
local vs = v.specials
if vs then
local kind = vs[1]
local size = #vs
if kind == "char" and size == 3 then -- what if more than 3
--
local one, two = vs[2], vs[3]
local first, second, combination = utfchar(one), utfchar(two), utfchar(unicode)
--
collapsed[first..second] = combination
backtrack(data[one],second,combination)
-- sort of obsolete:
local cgf = graphemes[first]
if not cgf then
cgf = { [second] = combination }
graphemes[first] = cgf
else
cgf[second] = combination
end
--
end
if (kind == "char" or kind == "compat") and (size > 2) and (v.mathclass or v.mathspec) then
setlist(unicode,vs,2,"specials")
end
end
local ml = v.mathlist
if ml then
mlists[unicode] = ml
end
end
-- these win:
for unicode, ml in next, mlists do
setlist(unicode,ml,1,"mathlist")
end
mlists = nil
if storage then
storage.register("characters/graphemes", graphemes, "characters.graphemes")
storage.register("characters/collapsed", collapsed, "characters.collapsed")
storage.register("characters/mathlists", mathlists, "characters.mathlists")
end
end
function characters.initialize() end -- dummy
local skippable = { }
local filesuffix = file.suffix
function utffilters.setskippable(suffix,value)
if value == nil then
value = true
end
if type(suffix) == "table" then
for i=1,#suffix do
skippable[suffix[i]] = value
end
else
skippable[suffix] = value
end
end
local p_collapse = nil -- so we can reset if needed
local function prepare()
local tree = utfchartabletopattern(collapsed)
-- p_collapse = Cs((tree/collapsed + p_utf8character)^0 * P(-1))
p_collapse = Cs((tree/collapsed + p_utf8character)^0)
end
function utffilters.collapse(str,filename)
if not p_collapse then
prepare()
end
if not str or str == "" or #str == 1 then
return str
elseif filename and skippable[filesuffix(filename)] then -- we could hash the collapsables or do a quicker test
return str
else
return lpegmatch(p_collapse,str) or str
end
end
local p_decompose = nil
local function prepare()
local tree = utfchartabletopattern(decomposed)
p_decompose = Cs((tree/decomposed + p_utf8character)^0 * P(-1))
end
function utffilters.decompose(str,filename) -- 3 to 4 times faster than the above
if not p_decompose then
prepare()
end
if str and str ~= "" and #str > 1 then
return lpegmatch(p_decompose,str)
end
if not str or str == "" or #str < 2 then
return str
elseif filename and skippable[filesuffix(filename)] then
return str
else
return lpegmatch(p_decompose,str) or str
end
return str
end
-- utffilters.addgrapheme(utfchar(318),'l','\string~')
-- utffilters.addgrapheme('c','a','b')
function utffilters.addgrapheme(result,first,second) -- can be U+ 0x string or utf or number
local result = charfromnumber(result)
local first = charfromnumber(first)
local second = charfromnumber(second)
if not graphemes[first] then
graphemes[first] = { [second] = result }
else
graphemes[first][second] = result
end
local pair = first .. second
if not collapsed[pair] then
collapsed[pair] = result
p_composed = nil
end
end
if interfaces then -- eventually this goes to char-ctx.lua
interfaces.implement {
name = "addgrapheme",
actions = utffilters.addgrapheme,
arguments = "3 strings",
}
end
-- --
local p_reorder = nil
-- local sorter = function(a,b) return b[2] < a[2] end
--
-- local function swapper(s,p,t)
-- local old = { }
-- for i=1,#t do
-- old[i] = t[i][1]
-- end
-- old = concat(old)
-- sort(t,sorter)
-- for i=1,#t do
-- t[i] = t[i][1]
-- end
-- local new = concat(t)
-- if old ~= new then
-- print("reordered",old,"->",new)
-- end
-- return p, new
-- end
-- -- the next one into stable for similar weights
local sorter = function(a,b)
return b[2] < a[2]
end
local function swapper(s,p,t)
sort(t,sorter)
for i=1,#t do
t[i] = t[i][1]
end
return p, concat(t)
end
-- -- the next one keeps similar weights in the original order
--
-- local sorter = function(a,b)
-- local b2, a2 = b[2], a[2]
-- if a2 == b2 then
-- return b[3] > a[3]
-- else
-- return b2 < a2
-- end
-- end
--
-- local function swapper(s,p,t)
-- for i=1,#t do
-- t[i][3] = i
-- end
-- sort(t,sorter)
-- for i=1,#t do
-- t[i] = t[i][1]
-- end
-- return p, concat(t)
-- end
-- at some point exceptions will become an option, for now it's an experiment
-- to overcome bugs (that have become features) in unicode .. or we might decide
-- for an extra ordering key in char-def that takes precedence over combining
local exceptions = {
-- frozen unicode bug
["َّ"] = "َّ", -- U+64E .. U+651 => U+651 .. U+64E
}
local function prepare()
local hash = { }
for k, v in sortedhash(characters.data) do
local combining = v.combining -- v.ordering or v.combining
if combining then
local u = utfchar(k)
hash[u] = { u, combining, 0 } -- slot 3 can be used in sort
end
end
local e = utfchartabletopattern(exceptions)
local p = utfchartabletopattern(hash)
p_reorder = Cs((e/exceptions + Cmt(Ct((p/hash)^2),swapper) + p_utf8character)^0) * P(-1)
end
function utffilters.reorder(str,filename)
if not p_reorder then
prepare()
end
if not str or str == "" or #str < 2 then
return str
elseif filename and skippable[filesuffix(filename)] then
return str
else
return lpegmatch(p_reorder,str) or str
end
return str
end
-- local collapse = utffilters.collapse
-- local decompose = utffilters.decompose
-- local reorder = utffilters.reorder
--
-- local c1, c2, c3 = "a", "̂", "̃"
-- local r2, r3 = "â", "ẫ"
-- local l1 = "ffl"
--
-- local str = c1..c2..c3 .. " " .. c1..c2 .. " " .. l1
-- local res = r3 .. " " .. r2 .. " " .. "ffl"
--
-- local text = io.loaddata("t:/sources/tufte.tex")
--
-- local function test(n)
-- local data = text .. string.rep(str,100) .. text
-- local okay = text .. string.rep(res,100) .. text
-- local t = os.clock()
-- for i=1,10000 do
-- collapse(data)
-- decompose(data)
-- -- reorder(data)
-- end
-- print(os.clock()-t,decompose(collapse(data))==okay,decompose(collapse(str)))
-- end
--
-- test(050)
-- test(150)
--
-- local old = "foo" .. string.char(0xE1) .. "bar"
-- local new = collapse(old)
-- print(old,new)
-- local one_old = "فَأَصَّدَّقَ دَّ" local one_new = utffilters.reorder(one_old)
-- local two_old = "فَأَصَّدَّقَ دَّ" local two_new = utffilters.reorder(two_old)
--
-- print(one_old,two_old,one_old==two_old,false)
-- print(one_new,two_new,one_new==two_new,true)
--
-- local test = "foo" .. utf.reverse("ؚ" .. "ً" .. "ٌ" .. "ٍ" .. "َ" .. "ُ" .. "ِ" .. "ّ" .. "ْ" ) .. "bar"
-- local done = utffilters.reorder(test)
--
-- print(test,done,test==done,false)
local f_default = formatters["[%U] "]
local f_description = formatters["[%s] "]
local function convert(n)
local d = data[n]
d = d and d.description
if d then
return f_description(d)
else
return f_default(n)
end
end
local pattern = Cs((p_utf8byte / convert)^1)
function utffilters.verbose(data)
return data and lpegmatch(pattern,data) or ""
end
return characters
|