From: Ryan Davis <ryand-ruby@...>
Date: 2012-10-15T16:46:48+09:00
Subject: Re: How to find where a method is defined


On Oct 14, 2012, at 22:13 , 前川　享仁 <takanobu_maekawa@pure-system.com> wrote:

> I created a file named hello_controller.rb and modifiedits code as bellow:
> ------------------------------------------
> class HelloController < ApplicationController
> def index
> render :text => 'hello world'
> end
> end
> --------------------------------------------
> 
> In the above I used the method named 'render', butI didn't know where it
> was defined. So I modified the program further like this:

[...lots of code to replicate how ruby finds methods...]

it's a lot easier than that. That's basically what ruby does when it is trying to execute a method. Instead, grab the method you want and ask it:

10001 % ruby19 -S irb
>> class X; def x; end; end
>> class Y < X; def y; p method(:x).source_location; end; end
>> Y.new.y
["(irb)", 1]

Not the best example, of course, but you get the idea.