method_source

(C) John Mair (banisterfiend) 2011

retrieve the sourcecode for a method

NOTE: This simply utilizes Method#source_location; it does not access the live AST.

method_source is a utility to return a method's sourcecode as a Ruby string. Also returns Proc and Lambda sourcecode.

Method comments can also be extracted using the comment method.

It is written in pure Ruby (no C).

• Some Ruby 1.8 support now available.

method_source provides the source and comment methods to the Method and UnboundMethod and Proc classes.

• Install the gem: gem install method_source
• Read the documentation
• See the source code

Example: display method source

Set.instance_method(:merge).source.display
# =>
def merge(enum)
  if enum.instance_of?(self.class)
    @hash.update(enum.instance_variable_get(:@hash))
  else
    do_with_enum(enum) { |o| add(o) }
  end

  self
end

Example: display method comments

Set.instance_method(:merge).comment.display
# =>
# Merges the elements of the given enumerable object to the set and
# returns self.

Limitations:

• Proc#source not available in Ruby 1.8
• Occasional strange behaviour in Ruby 1.8
• Cannot return source for C methods.
• Cannot return source for dynamically defined methods.

Special Thanks

Adam Sanderson for comment functionality.

Dmitry Elastic for the brilliant Ruby 1.8 source_location hack.