note
	description: "[
		Inherit from this class to benefit from a few predefined parsers and parser builders
		like `char' and `stringp', and debugging.
	]"
	legal: "See notice at end of class."
	status: "Pre-release"
	date: "$Date$"
	revision: "$Revision$"

class
	PEG_FACTORY

feature -- Predefined PEGs

	plus: PEG_ABSTRACT_PEG
			-- Character parser which parses '+'
		do
			Result := char ('+')

		end

	minus: PEG_ABSTRACT_PEG
			-- Character parser which parses '-'
		do
			Result := char ('-')

		end

	dot: PEG_ABSTRACT_PEG
			-- Character parser which parses '.'
		do
			Result := char ('.')

		end

	quote: PEG_ABSTRACT_PEG
			-- Character parser which parses '"'
		do
			Result := char ('"')

		end

	colon: PEG_ABSTRACT_PEG
			-- Character parser which parses ':'
		do
			Result := char (':')

		end

	comma: PEG_ABSTRACT_PEG
			-- Character parser which parses ','
		do
			Result := char (',')

		end

	back_slash: PEG_ABSTRACT_PEG
			-- Character parser which parses '\'
		do
			Result := char ('\')

		end

	open_square: PEG_ABSTRACT_PEG
			-- Character parser which parses '['
		do
			Result := char ('[')

		end

	close_square: PEG_ABSTRACT_PEG
			-- Character parser which parses ']'
		do
			Result := char (']')

		end

	open_curly: PEG_ABSTRACT_PEG
			-- Character parser which parses '{'
		do
			Result := char ('{')

		end

	close_curly: PEG_ABSTRACT_PEG
			-- Character parser which parses '}'
		do
			Result := char ('}')
		end

	hyphen: PEG_ABSTRACT_PEG
			-- Character parser which parses '-'
		do
			Result := char ('-')
		end

	underscore: PEG_ABSTRACT_PEG
			-- Character parser which parses '_'
		do
			Result := char ('_')
		end

	slash: PEG_ABSTRACT_PEG
			-- Character parser which parses '/'
		do
			Result := char ('/')
		end

	percent: PEG_ABSTRACT_PEG
			-- Character parser which parses '%'
		do
			Result := char ('%%')
		end

	equals: PEG_ABSTRACT_PEG
			-- Character parser which parses '='
		do
			Result := char ('=')
		end

	sharp: PEG_ABSTRACT_PEG
			-- Character parser which parses '#'
		do
			Result := char ('#')
		end

	ampersand: PEG_ABSTRACT_PEG
			-- Character parser which parses '&'
		do
			Result := char ('&')
		end

	open_parenthesis: PEG_ABSTRACT_PEG
			-- Character parser which parses '('
		do
			Result := char ('(')
		end

	close_parenthesis: PEG_ABSTRACT_PEG
			-- Character parser which parses ')'
		do
			Result := char (')')
		end

	digit: PEG_ABSTRACT_PEG
			-- Range parser which parses a digit [0-9]
		do
			Result := range ('0', '9')
		end

	digits: PEG_ABSTRACT_PEG
			-- Non-empty string of digits [0-9]
			-- Ommits the result
		do
			Result := range ('0', '9')
			Result := +Result
		ensure
			Result_attached: attached Result
		end

	lower_case: PEG_ABSTRACT_PEG
			-- Lower case letter
			-- Ommits the result
		do
			Result := range ('a', 'z')
		ensure
			Result_attached: attached Result
		end

	upper_case: PEG_ABSTRACT_PEG
			-- Upper case letter
			-- Ommits the result
		do
			Result := range ('A', 'Z')
		ensure
			Result_attached: attached Result
		end

	any: PEG_ANY
			--  The Parser which accepts anything (1 character)
			-- Ommits the result
		do
			create {PEG_ANY} Result.make
			Result.ommit_result
		ensure
			Result_attached: attached Result
		end

	rany: PEG_ANY
			-- The parser which accepts anything (1 character)
			-- Doesn't ommit the result
		do
			create {PEG_ANY} Result.make
		end

	whitespaces: PEG_ABSTRACT_PEG
			-- A chain of whitespaces
			-- Ommits the result
		do
			create {PEG_WHITE_SPACE_CHARACTER} Result.make
			Result.ommit_result
			Result := +Result
			Result.set_name ("whitespaces")
		end

feature --

	stringp (a_string: STRING): PEG_ABSTRACT_PEG
			-- Generates a parser which parses `a_string' which ommits results
		require
			a_string_valid: attached a_string and then not a_string.is_empty
		local
			l_i: INTEGER
		do
			create {PEG_SEQUENCE} Result.make
			from
				l_i := 1
			until
				l_i > a_string.count
			loop
				Result := Result + char (a_string [l_i])
				l_i := l_i + 1
			end
			Result.fixate
		ensure
			Result_attached: attached Result
		end

	rstringp (a_string: STRING): PEG_ABSTRACT_PEG
			-- Generates a parser which parses `a_string' which puts a string on the result list
		require
			a_string_valid: attached a_string and then not a_string.is_empty
		local
			l_i: INTEGER
		do
			create {PEG_SEQUENCE} Result.make
			from
				l_i := 1
			until
				l_i > a_string.count
			loop
				Result := Result + rchar (a_string [l_i])
				l_i := l_i + 1
			end
			Result := Result.consumer
			Result.fixate
		ensure
			Result_attached: attached Result
		end

	char (a_char: CHARACTER): PEG_CHARACTER
			-- Generates  Character Parser
		require
			a_char_attached: attached a_char
		do
			Result := rchar (a_char)
			Result.ommit_result
		ensure
			Result_attached: attached Result
		end

	rchar (a_character: CHARACTER): PEG_CHARACTER
			-- Builds an non-ommiter {PEG_CHARACTER}
		require
			a_character_attached: attached a_character
		do
			create Result.make_with_character (a_character)
		ensure
			Result_attached: attached result
		end

	range (a_first_char, a_last_char: CHARACTER): PEG_RANGE
			-- Builds an ommiter {PEG_CHARACTER} (doesn't put any characters to the result list)
		require
			a_first_char_attached: attached a_first_char
			a_last_char_attached: attached a_last_char
		do
			create Result.make_with_range (a_first_char, a_last_char)
			Result.ommit_result
		ensure
			Result_attached: attached Result
		end

feature -- Formatting

	format_debug (a_line_row: TUPLE [line: INTEGER; row: INTEGER]; a_source_path: STRING): STRING
			-- Formats the line/row information
		require
			a_line_row_attached: attached a_line_row
		do
			Result := "line: " + a_line_row.line.out + " row: " + a_line_row.row.out + " of file: " + a_source_path
		ensure
			Result_attached_and_not_empty: attached Result and then not Result.is_empty
		end

note
	copyright: "Copyright (c) 1984-2009, Eiffel Software"
	license: "GPL version 2 (see http://www.eiffel.com/licensing/gpl.txt)"
	licensing_options: "http://www.eiffel.com/licensing"
	copying: "[
			This file is part of Eiffel Software's Eiffel Development Environment.
			
			Eiffel Software's Eiffel Development Environment is free
			software; you can redistribute it and/or modify it under
			the terms of the GNU General Public License as published
			by the Free Software Foundation, version 2 of the License
			(available at the URL listed under "license" above).
			
			Eiffel Software's Eiffel Development Environment is
			distributed in the hope that it will be useful, but
			WITHOUT ANY WARRANTY; without even the implied warranty
			of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
			See the GNU General Public License for more details.
			
			You should have received a copy of the GNU General Public
			License along with Eiffel Software's Eiffel Development
			Environment; if not, write to the Free Software Foundation,
			Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
		]"
	source: "[
			Eiffel Software
			5949 Hollister Ave., Goleta, CA 93117 USA
			Telephone 805-685-1006, Fax 805-685-6869
			Website http://www.eiffel.com
			Customer support http://support.eiffel.com
		]"
end