if not modules then modules = { } end modules ['lang-rep'] = {
version = 1.001,
comment = "companion to lang-rep.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
-- A BachoTeX 2013 experiment, probably not that useful. Eventually I used a simpler
-- more generic example. I'm sure no one ever notices of even needs this code.
--
-- As a follow up on a question by Alan about special treatment of dropped caps I wonder
-- if I can make this one more clever (probably in a few more dev steps). For instance
-- injecting nodes or replacing nodes. It's a prelude to a kind of lpeg for nodes,
-- although (given experiences so far) we don't really need that. After all, each problem
-- is somewhat unique.
local type, tonumber, next = type, tonumber, next
local gmatch, gsub = string.gmatch, string.gsub
local utfbyte, utfsplit = utf.byte, utf.split
local P, C, U, Cc, Ct, Cs, lpegmatch = lpeg.P, lpeg.C, lpeg.patterns.utf8character, lpeg.Cc, lpeg.Ct, lpeg.Cs, lpeg.match
local find = string.find
local zwnj = 0x200C
local grouped = P("{") * ( Ct((U/utfbyte-P("}"))^1) + Cc(false) ) * P("}")-- grouped
local splitter = Ct((
#P("{") * (
P("{}") / function() return zwnj end
+ Ct(Cc("discretionary") * grouped * grouped * grouped)
+ Ct(Cc("noligature") * grouped)
)
+ U/utfbyte
)^1)
local stripper = P("{") * Cs((1-P(-2))^0) * P("}") * P(-1)
local trace_replacements = false trackers.register("languages.replacements", function(v) trace_replacements = v end)
local trace_details = false trackers.register("languages.replacements.details", function(v) trace_details = v end)
local report_replacement = logs.reporter("languages","replacements")
local glyph_code = nodes.nodecodes.glyph
local nuts = nodes.nuts
local getnext = nuts.getnext
local getprev = nuts.getprev
local getattr = nuts.getattr
local getid = nuts.getid
local getchar = nuts.getchar
local isglyph = nuts.isglyph
local setattr = nuts.setattr
local setlink = nuts.setlink
local setnext = nuts.setnext
local setprev = nuts.setprev
local setchar = nuts.setchar
local setattrlist = nuts.setattrlist
local insert_node_before = nuts.insert_before
local remove_node = nuts.remove
local copy_node = nuts.copy
local flush_list = nuts.flush_list
local insert_after = nuts.insert_after
local nodepool = nuts.pool
local new_disc = nodepool.disc
local texsetattribute = tex.setattribute
local unsetvalue = attributes.unsetvalue
local enableaction = nodes.tasks.enableaction
local v_reset = interfaces.variables.reset
local implement = interfaces.implement
local processors = typesetters.processors
local splitprocessor = processors.split
local replacements = languages.replacements or { }
languages.replacements = replacements
local a_replacements = attributes.private("replacements")
local a_noligature = attributes.private("noligature")
local lists = { }
local last = 0
local trees = { }
table.setmetatableindex(lists,function(lists,name)
last = last + 1
local list = { }
local data = { name = name, list = list, attribute = last }
lists[last] = data
lists[name] = data
trees[last] = list
return data
end)
lists[v_reset].attribute = unsetvalue -- so we discard 0
-- todo: glue kern attr
local function add(root,word,replacement)
local processor, replacement = splitprocessor(replacement,true) -- no check
replacement = lpegmatch(stripper,replacement) or replacement
local list = utfsplit(word,true)
local size = #list
for i=1,size do
local l = utfbyte(list[i])
if not root[l] then
root[l] = { }
end
if i == size then
local special = find(replacement,"{",1,true)
local newlist = lpegmatch(splitter,replacement)
root[l].final = {
word = word,
replacement = replacement,
processor = processor,
oldlength = size,
newcodes = newlist,
special = special,
}
end
root = root[l]
end
end
function replacements.add(category,word,replacement)
local root = lists[category].list
if type(word) == "table" then
for word, replacement in next, word do
add(root,word,replacement)
end
else
add(root,word,replacement or "")
end
end
-- local strip = lpeg.stripper("{}")
function languages.replacements.addlist(category,list)
local root = lists[category].list
if type(list) == "string" then
for new in gmatch(list,"%S+") do
local old = gsub(new,"[{}]","")
-- local old = lpegmatch(strip,new)
add(root,old,new)
end
else
for i=1,#list do
local new = list[i]
local old = gsub(new,"[{}]","")
-- local old = lpegmatch(strip,new)
add(root,old,new)
end
end
end
local function hit(a,head)
local tree = trees[a]
if tree then
local root = tree[getchar(head)]
if root then
local current = getnext(head)
local lastrun = false
local lastfinal = false
while current do
local char, id = isglyph(current)
-- if not char and id == glue_code then
-- char = " " -- if needed we can also deal with spaces and special nbsp and such
-- end
if char then
local newroot = root[char]
if not newroot then
return lastrun, lastfinal
else
local final = newroot.final
if final then
if trace_details then
report_replacement("hitting word %a, replacement %a",final.word,final.replacement)
end
lastrun = current
lastfinal = final
else
root = newroot
end
end
current = getnext(current)
else
break
end
end
if lastrun then
return lastrun, lastfinal
end
end
end
end
local function tonodes(list,template)
local head, current
for i=1,#list do
local new = copy_node(template)
setchar(new,list[i])
if head then
head, current = insert_after(head,current,new)
else
head, current = new, new
end
end
return head
end
function replacements.handler(head)
local current = head
local overload = attributes.applyoverloads
while current do
if getid(current) == glyph_code then
local a = getattr(current,a_replacements)
if a then
local last, final = hit(a,current)
if last then
local precurrent = getprev(current) or head
local oldlength = final.oldlength
local newcodes = final.newcodes
local newlength = newcodes and #newcodes or 0
if trace_replacement then
report_replacement("replacing word %a by %a",final.word,final.replacement)
end
if final.special then
-- easier is to delete and insert (a simple callout to tex would be more efficient)
-- maybe just walk over a replacement string instead
local prev = getprev(current)
local next = getnext(last)
local list = current
setnext(last)
setlink(prev,next)
current = prev
if not current then
head = nil
end
local i = 1
while i <= newlength do
local codes = newcodes[i]
if type(codes) == "table" then
local method = codes[1]
if method == "discretionary" then
local pre, post, replace = codes[2], codes[3], codes[4]
if pre then
pre = tonodes(pre,last)
end
if post then
post = tonodes(post,last)
end
if replace then
replace = tonodes(replace,last)
end
-- todo: also set attr
local new = new_disc(pre,post,replace)
setattrlist(new,last)
head, current = insert_after(head,current,new)
elseif method == "noligature" then
-- not that efficient to copy but ok for testing
local list = codes[2]
if list then
for i=1,#list do
local new = copy_node(last)
setchar(new,list[i])
setattr(new,a_noligature,1)
head, current = insert_after(head,current,new)
end
else
local new = copy_node(last)
setchar(new,zwnj)
head, current = insert_after(head,current,new)
end
else
-- todo
end
else
local new = copy_node(last)
setchar(new,codes)
head, current = insert_after(head,current,new)
end
i = i + 1
end
flush_list(list)
elseif newlength == 0 then
-- nothing gets replaced
current = getnext(last)
elseif oldlength == newlength then -- #old == #new
if final.word == final.replacement then
-- nothing to do but skip
else
for i=1,newlength do
setchar(current,newcodes[i])
current = getnext(current)
end
end
elseif oldlength < newlength then -- #old < #new
for i=1,newlength-oldlength do
local n = copy_node(current)
setchar(n,newcodes[i])
head, current = insert_node_before(head,current,n)
current = getnext(current)
end
for i=newlength-oldlength+1,newlength do
setchar(current,newcodes[i])
current = getnext(current)
end
else -- #old > #new
for i=1,oldlength-newlength do
head, current = remove_node(head,current,true)
end
for i=1,newlength do
setchar(current,newcodes[i])
current = getnext(current)
end
end
if overload then
overload(final,getnext(precurrent),getprev(current))
end
end
end
end
-- we're one ahead now but we need to because we handle words
current = getnext(current)
end
return head
end
local enabled = false
function replacements.set(n)
if n == v_reset then
n = unsetvalue
else
n = lists[n].attribute
if not enabled then
enableaction("processors","languages.replacements.handler")
if trace_replacements then
report_replacement("enabling replacement handler")
end
enabled = true
end
end
texsetattribute(a_replacements,n)
end
-- interface
implement {
name = "setreplacements",
actions = replacements.set,
arguments = "string"
}
implement {
name = "addreplacements",
actions = replacements.add,
arguments = "3 strings",
}
implement {
name = "addreplacementslist",
actions = replacements.addlist,
arguments = "2 strings",
}
