ParseTree 2.0.1 Released

ParseTree version 2.0.1 has been released!

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

As an example:

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


[:args, :arg1],
[:call, [:lvar, :arg1], :==, [:array, [:lit, 0]]],
[:return, [:lit, 1]],
[: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
  • ParseTree#parse_tree_for_string lets you parse arbitrary strings of
  • 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
  • Does not work on the core classes, as they are not ruby (yet).


  • 1 major enhancement:

    • Rewrote parse_tree_show to use parse_tree_for_string.
      • parse_tree_show adds -n=node filtering -u unifying, and -s
      • parse_tree_show no longer needs -f
  • 4 minor enhancements:

    • Added context stack to SexpProcessor! YAY!!!
    • Enforce type to be symbol in SexpProcessor… just makes life
    • Processing style change mode to UnifiedRuby. Prefer no rescues.
    • Sexp#structure is no longer destructive.
  • 4 bug fixes:

    • Added 1.8.4 compatibility fix.
    • Added args lifting in :defs in UnifiedRuby.
    • Fixed unifying argscat, splat, and a couple other oddities.
    • Added process_call to UnifiedRuby sigh I’m a tard.