1 files changed, 96 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/meta-lua.lua b/tex/context/base/mkiv/meta-lua.lua
new file mode 100644
index 000000000..42d036630
--- /dev/null
+++ b/tex/context/base/mkiv/meta-lua.lua
@@ -0,0 +1,96 @@
+if not modules then modules = { } end modules ['meta-lua'] = {
+    version   = 1.001,
+    comment   = "companion to meta-lua.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files",
+}
+
+-- Don't use this code yet. I use it in some experimental rendering of graphics
+-- based on output from database queries. It's not that pretty but will be
+-- considered when the (similar) lmx code is redone. Also, dropping the print
+-- variant makes it nicer. This experiment is part of playing with several template
+-- mechanisms. (Also see trac-lmx.)
+
+local P, V, Cs, lpegmatch = lpeg.P, lpeg.V, lpeg.Cs, lpeg.match
+local formatters = string.formatters
+local concat = table.concat
+local load, pcall = load, pcall
+
+local errorformatter  = formatters[ [[draw textext("\tttf error in template '%s'") ;]] ]
+local concatformatter = formatters[ [[local _t = { } local _n = 0 local p = function(s) _n = _n + 1 _t[_n] = s end %s return table.concat(_t," ")]] ]
+local appendformatter = formatters[ [[_n=_n+1 _t[_n]=%q]] ]
+
+local blua     = P("blua ")  / " "
+local elua     = P(" elua")  / " "
+local bluacode = P("<?lua ") / " "
+local eluacode = P(" ?>")    / " "
+
+local plua     = (blua * (1 - elua)^1 * elua)
+local pluacode = (bluacode * (1 - eluacode)^1 * eluacode)
+
+-- local methods = {
+--     both = Cs { "start",
+--         start    = (V("bluacode") + V("blua") + V("rest"))^0,
+--         blua     = plua,
+--         bluacode = pluacode,
+--         rest     = (1 - V("blua") - V("bluacode"))^1 / appendformatter,
+--     },
+--     xml = Cs { "start",
+--         start    = (V("bluacode") + V("rest"))^0,
+--         bluacode = pluacode,
+--         rest     = (1 - V("bluacode"))^1 / appendformatter,
+--     },
+--     xml = Cs ((pluacode + (1 - pluacode)^1 / appendformatter)^0),
+--     metapost = Cs { "start",
+--         start    = (V("blua") + V("rest"))^0,
+--         blua     = plua,
+--         rest     = (1 - V("blua"))^1 / appendformatter,
+--     },
+-- }
+
+local methods = {
+    both     = Cs ((pluacode + plua + (1 - plua - pluacode)^1 / appendformatter)^0),
+    xml      = Cs ((pluacode        + (1 -        pluacode)^1 / appendformatter)^0),
+    metapost = Cs ((           plua + (1 - plua           )^1 / appendformatter)^0),
+}
+
+methods.mp = methods.metapost
+
+-- Unfortunately mp adds a suffix ... also weird is that successive loading
+-- of the same file gives issues. Maybe some weird buffering goes on (smells
+-- similar to older write / read issues).
+
+mplib.finders.mpstemplate = function(specification,name,mode,ftype)
+    local authority = specification.authority
+    local queries   = specification.queries
+    local nameonly  = file.nameonly(queries.name   or "")
+    local method    = file.nameonly(queries.method or "")
+    local pattern   = methods[method] or methods.both
+    local data      = nil
+    if nameonly == "" then
+        data = errorformatter("no name")
+    elseif authority == "file" then
+        local foundname = resolvers.findfile(nameonly)
+        if foundname ~= "" then
+            data = io.loaddata(foundname)
+        end
+    elseif authority == "buffer" then
+        data = buffers.getcontent(nameonly)
+    end
+    data = data and lpegmatch(pattern,data)
+    data = data and concatformatter(data)
+    data = data and load(data)
+    if data then
+        local okay
+        okay, data = pcall(data)
+    end
+    if not data or data == "" then
+        data = errorformatter(nameonly)
+    end
+    local name = luatex.registertempfile(nameonly,true)
+    local data = metapost.checktexts(data)
+    io.savedata(name,data)
+    return name
+end
+