chunker/README
author Mahlon E. Smith <mahlon@martini.nu>
Sat, 22 Jan 2011 01:20:16 -0800
branchruby-modules
changeset 5 3d9956beee25
parent 2 e5c705047540
permissions -rw-r--r--
Bug metadata has been initialized.


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.