This post originated from an RSS feed registered with Ruby Buzz by Ryan Davis. Original Post: ParseTree version 2.0.0 has been released! Feed Title: Polishing Ruby Feed URL: http://blog.zenspider.com/index.rdf Feed Description: Musings on Ruby and the Ruby Community... Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Ryan Davis Latest Posts From Polishing Ruby

ParseTree is a C extension (using RubyInline) that extracts the parse tree for an entire class or a specific method and returns it as a s-expression (aka sexp) using ruby's arrays, strings, symbols, and integers.

As an example:

def conditional1(arg1)
  if arg1 == 0 then
    return 1
  end
  return 0
end

becomes:

[:defn,
  :conditional1,
  [:scope,
   [:block,
    [:args, :arg1],
    [:if,
     [:call, [:lvar, :arg1], :==, [:array, [:lit, 0]]],
     [:return, [:lit, 1]],
     nil],
    [:return, [:lit, 0]]]]]

• Uses RubyInline, so it just drops in.
• Includes SexpProcessor and CompositeSexpProcessor.
  • Allows you to write very clean filters.
• Includes UnifiedRuby, allowing you to automatically rewrite ruby quirks.
• ParseTree#parse_tree_for_string lets you parse arbitrary strings of ruby.
• Includes parse_tree_show, which lets you quickly snoop code.
  • echo "1+1" | parse_tree_show -f for quick snippet output.
• Includes parse_tree_abc, which lets you get abc metrics on code.
  • abc metrics = numbers of assignments, branches, and calls.
  • whitespace independent metric for method complexity.
• Includes parse_tree_deps, which shows you basic class level dependencies.
• Does not work on the core classes, as they are not ruby (yet).

Changes:

• 2 major enhancements:

  • Rewrite methods completely rewritten. Rewriters:
  • are no longer recursive.
  • are no longer required to empty the sexp coming in.
  • are depth first, so rewriter gets passed everything already normalized.
  • keep rewriting until type doesn't change.
  • are magical goodness.
  • Added UnifiedRuby module to aid others in writing clean SexpProcessors:
  • bmethod/dmethod/fbody unified with defn
  • fcall/vcall unified with call
  • resbody unified with itself (lots of different forms)

• 5 minor enhancements:

  • Add #modules to Module.
  • Add Sexp::for shortcut for Sexp.from_array ParseTree.translate(...).
  • Add parens for :block nodes as appropriate. May be overzealous.
  • Made add_to_parse_tree global for reuse by other C extensions.
  • Made test_ruby2ruby MUCH more rigorous with circular testing.

• 6 bug fixes:

  • Added $TESTING = true to pt_testcase.rb. OOPS!
  • Fixed some circular bugs, mostly by hacking them out, wrt operator precidence.
  • Fixed splat arg processing when arg has no name.
  • Fixed trinary operator.
  • Fixed BMETHOD with no arguments.
  • Removed hacky "self." thing for defs at top level PT use.

• http://www.zenspider.com/ZSS/Products/ParseTree/