add moon-tags script for generating tag file for moonscript classes

bin/moon-tags

@@ -0,0 +1,123 @@
+#!/usr/bin/env moon
+
+HEADER = [[
+!_TAG_FILE_FORMAT	2	/extended format/
+!_TAG_FILE_SORTED	1	/0=unsorted, 1=sorted, 2=foldcase/
+!_TAG_PROGRAM_AUTHOR	leaf corcoran	/leafot@gmail.com/
+!_TAG_PROGRAM_NAME	MoonTags	//
+!_TAG_PROGRAM_URL	https://github.com/leafo/moonscript	/GitHub repository/
+!_TAG_PROGRAM_VERSION	0.0.1	//
+]]
+
+-- see `ctags --list-kinds` for examples of kinds
+-- see `ctags --list-fields`
+
+argparse = require "argparse"
+
+parser = argparse "moon-tags", "Generate ctags style tags file for MoonScript files"
+parser\argument("files", "MoonScript files to generate tags for")\args "+"
+parser\flag "--include-line", "Include line number field for each tag"
+
+args = parser\parse [v for _, v in ipairs _G.arg]
+
+TAGS = {} -- the final output of tags
+
+literals = require "moonscript.parse.literals"
+import Indent from require "moonscript.parse.util"
+
+import P, S, C, Cc, Cg, Cb, Ct, Cs, V from require "lpeg"
+
+-- consome the rest of the file
+until_end = (1 - literals.Stop)^0
+whitespace = S"\t " -- not including newline
+ignore_line = Ct until_end -- tag it for empty line
+
+-- we have to do this double Ct to capture both the full line and the grouped captures
+Line = (p) -> Ct C Ct Cg(Indent, "indent") * p
+Type = (name) -> Cg Cc(name), "type"
+
+class_line = Line P"class" * whitespace^1 * Cg(literals.Name, "tag") * until_end * Type "class"
+-- TODO: support lapis style routes
+-- class_property = Line P("@")^-1 * Cg(literals.Name, "tag") * P":" * until_end * Type "property"
+
+method = P { P"=>" + P(1 - literals.Stop) * V(1) }
+class_method = Line P("@")^-1 * Cg(literals.Name, "tag") * P":" * method * until_end * Type "method"
+
+parse_lines = Ct P {
+  (class_line + class_method + ignore_line) * (P(-1) + literals.Break * V(1))
+}
+
+escape_tagaddress = (line_text) ->
+  replacements = P([[\]]) / [[\\]] + P([[/]]) / [[\/]] + P("\t") / [[\t]] + P("\r") / [[\r]] + P("\n") / [[\n]]
+  Cs((replacements + 1)^0)\match line_text
+
+for fname in *args.files
+  file = assert io.open fname
+  contents = assert file\read "*a"
+  lines = assert parse_lines\match contents
+
+  class_stack = {}
+
+  push_class = (cls) ->
+    assert cls.type == "class", "not a class match"
+    -- remove classes that are longer in scope due to indentation
+    for i=#class_stack,1,-1
+      top = class_stack[i]
+
+      if cls.indent <= top.indent
+        table.remove class_stack, i
+      else
+        break
+
+    table.insert class_stack, cls
+
+  -- find the class this property is associated with based on change in indent
+  -- the expeted indent is written to `step` on the first proprety
+  find_class = (property) ->
+    for i=#class_stack,1,-1
+      top = class_stack[i]
+      step = property.indent - top.indent
+
+      if step > 0
+        if top.step == nil
+          top.step = step
+
+        if step == top.step
+          return top
+
+  for line_no, line in ipairs lines
+    continue unless next line
+
+    {line_text, properties} = line
+
+    fields = {"language:moon"}
+    if args.include_line
+      table.insert fields, 1, "line:#{line_no}"
+
+    switch properties.type
+      when "method"
+        if cls = find_class properties
+          table.insert fields, "class:#{cls.tag}"
+
+          table.insert TAGS, {
+            properties.tag
+            fname
+            "/^#{escape_tagaddress line_text}$/;\""
+            "f"
+            table.concat fields, " "
+          }
+      when "class"
+        push_class properties
+
+        table.insert TAGS, {
+          properties.tag
+          fname
+          "/^#{escape_tagaddress line_text}$/;\""
+          "c"
+          table.concat fields, " "
+        }
+
+print HEADER
+tag_lines = [table.concat(t, "\t") for t in *TAGS]
+table.sort tag_lines
+print table.concat tag_lines, "\n"