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parser-combinators: reimplement <&> 

This refactoring removes the 3 word implementation of <&> and replaces it with bbetter lazy list functionality. Although parser combinators will be rewritten this algorithm for <&> will remain mostly the same.
chris.double 2006-10-05 11:03:46 +00:00
parent f3abd0c53d
commit 11377d538d
1 changed files with 11 additions and 41 deletions
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52
contrib/parser-combinators/parser-combinators.factor
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@ -1,25 +1,6 @@
! Copyright (C) 2004 Chris Double. ! Copyright (C) 2004 Chris Double.
! ! See http://factorcode.org/license.txt for BSD license.
! Redistribution and use in source and binary forms, with or without !
! modification, are permitted provided that the following conditions are met:
!
! 1. Redistributions of source code must retain the above copyright notice,
! this list of conditions and the following disclaimer.
!
! 2. Redistributions in binary form must reproduce the above copyright notice,
! this list of conditions and the following disclaimer in the documentation
! and/or other materials provided with the distribution.
!
! THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
! INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
! FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
! DEVELOPERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
! SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
! OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
! WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
! OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
! ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
USING: lazy-lists kernel sequences strings math io arrays errors namespaces ; USING: lazy-lists kernel sequences strings math io arrays errors namespaces ;
IN: parser-combinators IN: parser-combinators
@ -112,30 +93,19 @@ TUPLE: parse-result parsed unparsed ;
#! Return a fail-parser. #! Return a fail-parser.
[ fail-parser ] ; [ fail-parser ] ;
: <&>-do-parser3 ( <parse-result> x -- result ) : <&>-parser ( input parser1 parser2 -- parser )
#! Called by <&>-do-parser2 on each result of the
#! parse from parser2.
>r dup parse-result-unparsed swap parse-result-parsed r>
swap 2array swap <parse-result> ;
: <&>-do-parser2 ( <parse-result> parser2 -- result )
#! Called by the <&>-parser on each result of the
#! successfull parse of parser1. It's input is the
#! cons containing the data parsed and the remaining
#! input. This word will parser2 on the remaining input
#! returning a new cons cell containing the combined
#! parse result.
>r dup parse-result-parsed swap parse-result-unparsed r>
call swap
[ <&>-do-parser3 ] curry lmap ;
: <&>-parser ( input parser1 parser2 -- llist )
#! Parse 'input' by sequentially combining the #! Parse 'input' by sequentially combining the
#! two parsers. First parser1 is applied to the #! two parsers. First parser1 is applied to the
#! input then parser2 is applied to the rest of #! input then parser2 is applied to the rest of
#! the input strings from the first parser. #! the input strings from the first parser.
>r call r> >r call r> swap [
[ <&>-do-parser2 ] curry lmap list>array nil [ lappend ] reduce ; dup parse-result-unparsed rot call
[
>r parse-result-parsed r>
[ parse-result-parsed 2array ] keep
parse-result-unparsed <parse-result>
] lmap-with
] lmap-with lconcat ;
: <&> ( parser1 parser2 -- parser ) : <&> ( parser1 parser2 -- parser )
#! Sequentially combine two parsers, returning a parser #! Sequentially combine two parsers, returning a parser