Ruby block to string instead of executing [duplicate]

Answer 1

Duplicate: Printing the source code of a Ruby block

sudo gem install ParseTree
sudo gem install ruby2ruby

then

require 'rubygems'
require 'parse_tree'
require 'parse_tree_extensions'
require 'ruby2ruby'

def block_as_string &block
    block.to_ruby
end

results in

irb(main):008:0> block_as_string {puts 'x'}
=> "proc { puts(\"x\") }"

Answer 2

You want the ruby2ruby gem, which does this nicely. Unfortunately, to analyze a block this gem depends on ParseTree, which is unsupported in Ruby 1.9.

Answer 3

If you're on Ruby 1.9, you can use the sourcify gem. It provides Proc#to_source, which is like ParseTree's Proc#to_ruby.

When using sourcify, if you have nested procs in your source code, you might have to help it along with the :attached_to option:

## (Works in Ruby 1.8) Using ParseTree (with parse_tree_extensions)
block.to_ruby
## (Works in Ruby 1.9) Using sourcify
block.to_source
## Try this if you get Sourcify::NoMatchingProcError or Sourcify::MultipleMatchingProcsPerLineError
block.to_source :attached_to => :name_of_block_in_source_code

I posted about ParseTree and Ruby 1.9 in my company's blog.