class Proc

# File lib/proc_source.rb, line 5
def proc_source
  return @source if @source
  filepath, start_pos = source_location

  code = File.readlines(filepath)[(start_pos-1)..-1].join
  tokens = Ripper.lex(code).drop_while do |t|
    !proc_token?(t)
  end

  @source = " " * tokens[0][0][1].to_i

  while token = tokens.shift
    @source += token[2]
    break if valid_proc_source?(@source)
  end

  @source
end

# File lib/proc_source.rb, line 26
def proc_token?(token)
  _pos, event, ident = *token
  return true if event == :on_const && ident == "Proc"
  return true if event == :on_ident && ident == "lambda"
  return true if event == :on_ident && ident == "proc"
  return true if event == :on_kw && ident == "do"
  return true if event == :on_lbrace
  return true if event == :on_tlambda
  false
end

# File lib/proc_source.rb, line 37
def valid_proc_source?(source)
  source = "Proc.new " + source if source =~ /\A\s*(do|{)/
  eval(source).instance_of?(Proc)
rescue SyntaxError, ArgumentError
  false
end