86 lines
2.5 KiB
Factor
86 lines
2.5 KiB
Factor
! Copyright (C) 2008 Doug Coleman.
|
|
! See http://factorcode.org/license.txt for BSD license.
|
|
USING: accessors assocs combinators combinators.lib kernel
|
|
math math.ranges quotations sequences regexp2.parser
|
|
regexp2.classes combinators.short-circuit assocs.lib
|
|
sequences.lib regexp2.utils ;
|
|
IN: regexp2.traversal
|
|
|
|
TUPLE: dfa-traverser
|
|
dfa-table
|
|
traversal-flags
|
|
capture-groups
|
|
{ capture-group-index integer }
|
|
{ lookahead-counter integer }
|
|
last-state current-state
|
|
text
|
|
start-index current-index
|
|
matches ;
|
|
|
|
: <dfa-traverser> ( text regexp -- match )
|
|
[ dfa-table>> ] [ dfa-traversal-flags>> ] bi
|
|
dfa-traverser new
|
|
swap >>traversal-flags
|
|
swap [ start-state>> >>current-state ] keep
|
|
>>dfa-table
|
|
swap >>text
|
|
0 >>start-index
|
|
0 >>current-index
|
|
V{ } clone >>matches
|
|
V{ } clone >>capture-groups ;
|
|
|
|
: final-state? ( dfa-traverser -- ? )
|
|
[ current-state>> ] [ dfa-table>> final-states>> ] bi
|
|
key? ;
|
|
|
|
: text-finished? ( dfa-traverser -- ? )
|
|
[ current-index>> ] [ text>> length ] bi >= ;
|
|
|
|
: save-final-state ( dfa-straverser -- )
|
|
[ current-index>> ] [ matches>> ] bi push ;
|
|
|
|
: match-done? ( dfa-traverser -- ? )
|
|
dup final-state? [
|
|
dup save-final-state
|
|
] when text-finished? ;
|
|
|
|
: increment-state ( dfa-traverser state -- dfa-traverser )
|
|
>r [ 1+ ] change-current-index dup current-state>> >>last-state r>
|
|
first >>current-state ;
|
|
|
|
: match-failed ( dfa-traverser -- dfa-traverser )
|
|
V{ } clone >>matches ;
|
|
|
|
: match-literal ( transition from-state table -- to-state/f )
|
|
transitions>> [ at ] [ 2drop f ] if-at ;
|
|
|
|
: match-class ( transition from-state table -- to-state/f )
|
|
transitions>> at* [
|
|
[ drop class-member? ] assoc-with assoc-find [ nip ] [ drop ] if
|
|
] [ drop ] if ;
|
|
|
|
: match-default ( transition from-state table -- to-state/f )
|
|
[ nip ] dip transitions>>
|
|
[ t swap [ drop f ] unless-at ] [ drop f ] if-at ;
|
|
|
|
: match-transition ( obj from-state dfa -- to-state/f )
|
|
{ [ match-literal ] [ match-class ] [ match-default ] } 3|| ;
|
|
|
|
: setup-match ( match -- obj state dfa-table )
|
|
{
|
|
[ current-index>> ] [ text>> ]
|
|
[ current-state>> ] [ dfa-table>> ]
|
|
} cleave
|
|
[ nth ] 2dip ;
|
|
|
|
: do-match ( dfa-traverser -- dfa-traverser )
|
|
dup match-done? [
|
|
dup setup-match match-transition
|
|
[ increment-state do-match ] when*
|
|
] unless ;
|
|
|
|
: return-match ( dfa-traverser -- interval/f )
|
|
dup matches>>
|
|
[ drop f ]
|
|
[ [ start-index>> ] [ peek ] bi* 1 <range> ] if-empty ;
|