add update version script to build.lua

build.lua

@@ -15,3 +15,36 @@ tdslocations = {
 	}
 unpackfiles = {"*.map"}
 unpackexe = "teckit_compile"
+
+tagfiles = {"tex/polyglossia.sty", "tex/*.ldf", "tex/*.lua", "doc/polyglossia.tex", "README.md"}
+function update_tag(file,content,tagname,tagdate)
+  if string.match(file, "%.ldf$") then
+    return string.gsub(content,
+      "%% Language definition file %(part of polyglossia v%d%.%d+ %-%- %d%d%d%d/%d%d/%d%d%)\n",
+      "%% Language definition file (part of polyglossia " .. tagname .. " -- " .. tagdate .. ")\n")
+  elseif string.match(file, "%.lua$") then
+    return string.gsub(content,
+      "\n%-%- part of polyglossia v%d%.%d+ %-%- %d%d%d%d/%d%d/%d%d\n",
+      "\n-- part of polyglossia " .. tagname .. " -- " .. tagdate .. "\n")
+  elseif file == "polyglossia.tex" then
+    return string.gsub(content,
+      "\n\\subsection%*{%d%.%d %(forthcoming%)}\n",
+      "\n\\subsection*{" .. tagname .. " (" .. tagdate .. ")}\n")
+  elseif file == "polyglossia.sty" then
+    return string.gsub(content,
+      "\n  {polyglossia} {%d%d%d%d/%d%d/%d%d} {v%d%.%d+}\n",
+      "\n  {polyglossia} {" .. tagdate .. "} {" .. tagname .. "}\n")
+  elseif file == "README.md" then
+    content = string.gsub(content,
+      "# THE POLYGLOSSIA PACKAGE v%d%.%d\n",
+      "# THE POLYGLOSSIA PACKAGE " .. tagname .. "\n")
+    local names = {"Arthur", "Udi", "Jürgen"}
+    for name = 1, #names do
+      content  = string.gsub(content,
+        "(%-%d%d%d%d) (" .. names[name] .. ")",
+        "-" .. string.sub(tagdate, 1, 4) .. " %2")
+    end
+    return content
+  end
+  return content
+end