wiki:Chunker
Last modified 5 years ago Last modified on 07/24/09 08:11:30

Chunker

Preface

Ruby provides an automatic constant called DATA, which is an IO object that references all text in the current file under an __END__ token.

I find it convenient to use the __END__ area to store all sorts of stuff, rather than have to worry about distributing separate files.

The problem

The DATA constant is determined from whatever ruby believes $0 to be. It doesn't work inside of other required libraries, so you'll see stuff like this all the time:

END = File.open( __FILE__ ).read.split( /^__END__/, 2 ).last

It works, but it's more work than I want to do.

A workaround

Chunker solves this by parsing __END__ tokens for you, and making it available in the form of a 'DATA_END' constant. It installs this constant into the class that includes Chunker, so you can use it again and again, assuming you use a different file for each class.

It also automatically parses out other things that look like tokens, so you can easily have multiple, distinct documents all embedded into the __END__ block.

Usage

There is no direct interface to Chunker. Just include it from a class to have that file's __END__ data blocks magically become DATA_* IO constants within that class.

Example

This produces the string "Yep.\n".

require 'chunker'
class Foom
    include Chunker
end

puts Foom.new.class.const_get( :DATA_WICKED ).read

__END__
Stuff in the END block!
__WOW__
Ultimate success!
__WICKED__
Yep.

Downloads

Get the latest gem here. Or a tarball.

Development

You can also check out the source via Mercurial from the following uri:

% hg clone http://code.martini.nu/ruby-modules/