#

#

#

### Namespace for the datablock parser.

###

module Chunker

	require 'strscan'

	require 'stringio'

	# SVN Revision

	#

	SVNRev = %q$Rev$

	# SVN Id

	#

	SVNId = %q$Id$

	# Package version

	#

	VERSION = '0.1'

	### Parser class for __END__ data blocks.

	###

	class DataParser

		# The mark for a DATA block.

		#

		# The mark for a 'sub' block.

		#

		### Constructor: Given a +klass+ and an +io+ to the class file,

		### extract the data blocks and install constants.

		###

		def initialize( klass, io )

			io.open if io.closed?

			@klass   = klass

			@scanner = StringScanner.new( end_string )

			io.close

				# put each chunk into its own constant

				self.extract_blocks

			else

				# no sub blocks, put the whole mess into DATA_END

				@klass.const_set( :DATA_END, StringIO.new( end_string ) )

			end

		end

		#########

		protected

		#########

		### Parse the current +io+ for data blocks, set contents to

		### IO constants in the including class.

		###

		def extract_blocks

			label = nil

				data = ''

				# of entire data block.)

				#

				if label.nil?

					label = 'END'

					data  = @scanner.pre_match

					@scanner.pos = self.next_position

				else

					label = @scanner[1]

						#

						data         = data[ 0, data.length - @scanner[0].length ]

						@scanner.pos = self.next_position

					else

						# No additional blocks

						#

						data = @scanner.rest

					end

				end

				# Add the IO constant to the class that included me.

				#

				@klass.const_set( "DATA_#{label}".to_sym, StringIO.new( data ) )

			end

		end

		### Return the next scanner position for searching.

		###

		def next_position

			return @scanner.pos - @scanner[0].length

		end

	end

	###

    def self.included( klass )

		# klass.instance_eval{ __FILE__ }   awww, nope.

		io = File.open( caller(1).last.sub(/:.*?$/, ''), 'r' )

		DataParser.new( klass, io )

    end

end