factor/basis/regexp/compiler/compiler.factor

145 lines
4.0 KiB
Factor

! Copyright (C) 2009 Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: regexp.classes kernel sequences regexp.negation
quotations assocs fry math locals combinators sets
accessors words compiler.units kernel.private strings
sequences.private arrays namespaces unicode.breaks
regexp.transition-tables combinators.short-circuit ;
IN: regexp.compiler
GENERIC: question>quot ( question -- quot )
SYMBOL: shortest?
SYMBOL: backwards?
<PRIVATE
M: t question>quot drop [ 2drop t ] ;
M: f question>quot drop [ 2drop f ] ;
M: beginning-of-input question>quot
drop [ drop zero? ] ;
M: end-of-input question>quot
drop [ length = ] ;
M: end-of-file question>quot
drop [
{
[ length swap - 2 <= ]
[ swap tail { "\n" "\r\n" "\r" "" } member? ]
} 2&&
] ;
M: $ question>quot
drop [ { [ length = ] [ ?nth "\r\n" member? ] } 2|| ] ;
M: ^ question>quot
drop [ { [ drop zero? ] [ [ 1 - ] dip ?nth "\r\n" member? ] } 2|| ] ;
M: $unix question>quot
drop [ { [ length = ] [ ?nth CHAR: \n = ] } 2|| ] ;
M: ^unix question>quot
drop [ { [ drop zero? ] [ [ 1 - ] dip ?nth CHAR: \n = ] } 2|| ] ;
M: word-break question>quot
drop [ word-break-at? ] ;
: (execution-quot) ( next-state -- quot )
! The conditions here are for lookaround and anchors, etc
dup condition? [
[ question>> question>quot ] [ yes>> ] [ no>> ] tri
[ (execution-quot) ] bi@
'[ 2dup @ _ _ if ]
] [ '[ _ execute ] ] if ;
: execution-quot ( next-state -- quot )
dup sequence? [ first ] when
(execution-quot) ;
TUPLE: box contents ;
C: <box> box
: condition>quot ( condition -- quot )
! Conditions here are for different classes
dup condition? [
[ question>> ] [ yes>> ] [ no>> ] tri
[ condition>quot ] bi@
'[ dup _ class-member? _ _ if ]
] [
contents>>
[ [ 3drop ] ] [ execution-quot '[ drop @ ] ] if-empty
] if ;
: non-literals>dispatch ( literals non-literals -- quot )
[ swap ] assoc-map ! we want state => predicate, and get the opposite as input
swap keys f assoc-answers
table>condition [ <box> ] condition-map condition>quot ;
: literals>cases ( literal-transitions -- case-body )
[ execution-quot ] assoc-map ;
: split-literals ( transitions -- case default )
{ } assoc-like [ first integer? ] partition
[ [ literals>cases ] keep ] dip non-literals>dispatch ;
: advance ( index backwards? -- index+/-1 )
-1 1 ? + >fixnum ; inline
: check ( index string backwards? -- in-bounds? )
[ drop -1 eq? not ] [ length < ] if ; inline
:: step ( last-match index str quot final? backwards? -- last-index/f )
final? index last-match ?
index str backwards? check [
index backwards? advance str
index str nth-unsafe
quot call
] when ; inline
: transitions>quot ( transitions final-state? -- quot )
dup shortest? get and [ 2drop [ drop nip ] ] [
[ split-literals swap case>quot ] dip backwards? get
'[ { fixnum string } declare _ _ _ step ]
] if ;
: word>quot ( word dfa -- quot )
[ transitions>> at ]
[ final-states>> in? ] 2bi
transitions>quot ;
: states>code ( words dfa -- )
'[
dup _ word>quot
(( last-match index string -- ? ))
define-declared
] each ;
: states>words ( dfa -- words dfa )
dup transitions>> keys [ gensym ] H{ } map>assoc
[ transitions-at ]
[ values ]
bi swap ;
: dfa>main-word ( dfa -- word )
states>words [ states>code ] keep start-state>> ;
: word-template ( quot -- quot' )
'[ drop [ f ] 2dip over array-capacity? _ [ 2drop ] if ] ;
PRIVATE>
: dfa>word ( dfa -- quot )
dfa>main-word execution-quot word-template
(( start-index string regexp -- i/f )) define-temp ;
: dfa>shortest-word ( dfa -- word )
t shortest? [ dfa>word ] with-variable ;
: dfa>reverse-word ( dfa -- word )
t backwards? [ dfa>word ] with-variable ;
: dfa>reverse-shortest-word ( dfa -- word )
t backwards? [ dfa>shortest-word ] with-variable ;