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]]]]]