%D \module
%D   [       file=m-translate,
%D        version=2008.10.09,
%D          title=\CONTEXT\ Modules,
%D       subtitle=Translations,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

%D We can make this module more clever (wildcards and such) but since
%D it's only a demo we stick to the simple case for now. After all, it's
%D better to fix your source.

\startluacode
    local translators = { }

    moduledata.translators = translators

    local compiled, list = nil, nil

 -- function translators.register(from,to)
 --     local l = lpeg.P(from)/to
 --     if not list then
 --         list = l
 --     else
 --         list = list + l
 --     end
 --     compiled = nil
 -- end
 --
 -- function translators.translate(s)
 --     if list then
 --         if not compiled then
 --             compiled = lpeg.Cs((list + lpeg.P(1))^0)
 --         end
 --         return compiled:match(s)
 --     else
 --         return s
 --     end
 -- end

    -- local function prepare()

    function translators.register(from,to)
        if not list then
            list = { [from] = to }
        else
            list[from] = to
        end
        compiled = nil
    end

    function translators.translate(s)
        if list then
            if not compiled then
                local tree = lpeg.utfchartabletopattern(list)
                compiled = lpeg.Cs((tree/list + lpeg.patterns.utf8character)^0 * lpeg.P(-1)) -- the P(1) is needed in order to accept non utf
            end
            return compiled:match(s)
        else
            return s
        end
    end

    local textlineactions = resolvers.openers.helpers.textlineactions

    utilities.sequencers.appendaction(textlineactions,"after","moduledata.translators.translate")

    function translators.enable()
        utilities.sequencers.enableaction(textlineactions,"moduledata.translators.translate")
    end

    function translators.disable()
        utilities.sequencers.disableaction(textlineactions,"moduledata.translators.translate")
    end

    function translators.reset(s)
        translators.enable()
        list, compiled = nil, nil
    end

    translators.disable()
\stopluacode

\unprotect

\unexpanded\def\translateinput
  {\dodoubleargument\module_translate_input}

\def\module_translate_input[#1][#2]%
  {\ctxlua{moduledata.translators.register(\!!bs#1\!!es,\!!bs#2\!!es)}}

\unexpanded\def\resetinputtranslation
  {\ctxlua{moduledata.translators.reset()}}

\unexpanded\def\enableinputtranslation
  {\ctxlua{moduledata.translators.enable()}}

\unexpanded\def\disableinputtranslation
  {\ctxlua{moduledata.translators.disable()}}

\unexpanded\def\readtranslatedfile#1%
  {\enableinputtranslation
   \readfile{#1}\donothing\donothing
   \disableinputtranslation}

\protect

\continueifinputfile{m-translate.mkiv}

\starttext

    \translateinput[Moica][Mojca]
  % \translateinput[Idris][Idris (aka ادريس)]
    \translateinput[Idris][Idris (aka <something arabic here>)]

    \enableinputtranslation

    Well, it's not that hard to satisfy Idris' and Moicas \TEX\ needs.

    \readtranslatedfile{tufte}

\stoptext