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Diffstat (limited to 'tex/context/base/lang-rep.lua')
| -rw-r--r-- | tex/context/base/lang-rep.lua | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/tex/context/base/lang-rep.lua b/tex/context/base/lang-rep.lua new file mode 100644 index 000000000..3dec9503e --- /dev/null +++ b/tex/context/base/lang-rep.lua @@ -0,0 +1,196 @@ +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. + +local utfbyte, utfsplit = utf.byte, utf.split + +local trace_replacements = false trackers.register("languages.replacements", function(v) trace_replacements = v end) +local trace_detail = false trackers.register("languages.replacements.detail", function(v) trace_detail = v end) + +local report_replacement = logs.reporter("languages","replacements") + +local glyph_code = nodes.nodecodes.glyph + +local nuts = nodes.nuts +local tonut = nuts.tonut +local tonode = nuts.tonode + +local setfield = nuts.setfield +local getnext = nuts.getnext +local getattr = nuts.getattr +local getid = nuts.getid +local getchar = nuts.getchar + +local insert_node_before = nodes.insert_before +local remove_node = nodes.remove +local copy_node = nodes.copy + +local texsetattribute = tex.setattribute +local unsetvalue = attributes.unsetvalue + +local v_reset = interfaces.variables.reset + +local replacements = languages.replacements or { } +languages.replacements = replacements + +local a_replacements = attributes.private("replacements") + +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) + +local function add(root,word,replacement) + local list = utfsplit(word,true) + for i=1,#list do + local l = utfbyte(list[i]) + if not root[l] then + root[l] = { } + end + if i == #list then + local newlist = utfsplit(replacement,true) + for i=1,#newlist do + newlist[i] = utfbyte(newlist[i]) + end + root[l].final = { + word = word, + replacement = replacement, + oldlength = #list, + newcodes = newlist, + } + 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 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 and getid(current) == glyph_code do + local newroot = root[getchar(current)] + if not newroot then + return lastrun, lastfinal + else + local final = newroot.final + if final then + if trace_detail 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) + end + if lastrun then + return lastrun, lastfinal + end + end + end +end + +function replacements.handler(head) + local current = tonut(head) + local done = false + while current do + if current.id == glyph_code then + local a = getattr(current,a_replacements) + if a then + local last, final = hit(a,current) + if last then + local oldlength = final.oldlength + local newcodes = final.newcodes + local newlength = #newcodes + if report_replacement then + report_replacement("replacing word %a by %a",final.word,final.replacement) + end + if oldlength == newlength then -- #old == #new + for i=1,newlength do + setfield(current,"char",newcodes[i]) + current = current.next + end + elseif oldlength < newlength then -- #old < #new + for i=1,newlength-oldlength do + local n = copy_node(current) + setfield(n,"char",newcodes[i]) + head, current = insert_node_before(head,current,n) + current = getnext(current) + end + for i=newlength-oldlength+1,newlength do + setfield(current,"char",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 + setfield(current,"char",newcodes[i]) + current = getnext(current) + end + end + done = true + end + end + end + current = getnext(current) + end + return tonode(head), done +end + +local enabled = false + +function replacements.set(n) -- number or 'reset' + if n == v_reset then + n = unsetvalue + else + n = lists[n].attribute + if not enabled then + nodes.tasks.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 + +commands.setreplacements = replacements.set +commands.addreplacements = replacements.add |