elua: initial work on parser part of the extractor

src/bin/elua/modules/xgettext/parser.lua

@@ -0,0 +1,28 @@
+-- Elua xgettext: parser
+
+local lexer = require("xgettext.lexer")
+
+local yield = coroutine.yield
+
+local saved_comments = {}
+
+local parse = function(ls, keywords)
+    yield()
+    local tok = ls.token
+    while tok.name do
+        if tok.name == "<comment>" then
+            saved_comments[#saved_comments + 1] = tok.value
+            ls:get()
+        elseif tok.name == "<name>" and keywords[tok.value] then
+            local cmt = saved_comments[#saved_comments]
+            saved_comments = {}
+        else
+            ls:get()
+        end
+    end
+end
+
+return { init = function (chunkname, input, keywords)
+    local ls = lexer.init(chunkname, input)
+    ls:get()
+end }