From: Eric Christopherson <echristopherson@...>
Date: 2011-02-18T09:03:55+09:00
Subject: Re: Ruby reflection - get method definition as a string

On Thu, Feb 17, 2011 at 4:53 PM, Florian Gilcher <flo@andersground.net> wrote:
>
> On Feb 17, 2011, at 8:40 PM, Anurag Priyam wrote:
>
>>> Hi Folks - I am running some ruby tests and would like to print out
>>> the actual test to the console or store it to a file.  The tests are
>>> written as classes with a setup, run, and teardown method.
>>> So here's my question: is there a way to get the class definition or
>>> method definitions as a "string", so that I can print it out (to a
>>> file or console)?
>>> I know ruby supports a lot of reflection (like .methods
>>> or .constants), but I'm not seeing how to do this.
>>
>> A very non-elegant, trivial way using Ruby's DATA stream ;) :
>>
>> # test.rb
>> def foo
>>  puts "hi"
>> end
>>
>> flag = nil
>> DATA.tap{|x| x.rewind}.readlines.each do |line|
>>  flag = true if line =~ /^def/
>>  puts line if flag
>>  flag = false if line =~ /^end/
>> end
>> __END__

Cool, I didn't realize you access the source file using tap and rewind.

>>
>> $ ruby test.rb
>> def foo
>>  puts "hi"
>> end
>>
>> Obviously you will have to come up with better heuristics to determine
>> the end of a method.
>>
>
> In Ruby 1.9, you can retrieve the place where the method was defined using #source_location:
>
>  def foo
>
>  end
>
>  method(:foo).source_location #=> ["file.rb", 1]
>
> The same goes for procs:
>
>  def foo(&block)
>    puts block.source_location.inspect
>  end
>
>  foo do
>
>  end #=> ["file.rb", 5]

I just discovered #source_location a week or so ago, but I immediately
wondered if there was a way to discern the end of a block or method. I
never found one. Might one be added in a future Ruby?