1 ! Copyright (C) 2008, 2009 Doug Coleman, Daniel Ehrenberg.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays assocs grouping kernel
4 locals math namespaces sequences fry quotations
5 math.order math.ranges vectors unicode.categories
6 regexp.transition-tables words sets hashtables combinators.short-circuit
7 unicode.case.private regexp.ast regexp.classes ;
10 ! This uses unicode.case.private for ch>upper and ch>lower
11 ! but case-insensitive matching should be done by case-folding everything
12 ! before processing starts
18 : next-state ( -- state )
19 state [ get ] [ inc ] bi ;
23 : set-each ( keys value hashtable -- )
24 '[ _ swap _ set-at ] each ;
26 : options>hash ( options -- hashtable )
28 [ [ on>> t ] dip set-each ]
29 [ [ off>> f ] dip set-each ] 2bi
32 : using-options ( options quot -- )
33 [ options>hash option-stack [ ?push ] change ] dip
34 call option-stack get pop* ; inline
36 : option? ( obj -- ? )
37 option-stack get assoc-stack ;
39 GENERIC: nfa-node ( node -- start-state end-state )
41 : add-simple-entry ( obj -- start-state end-state )
42 [ next-state next-state 2dup ] dip
43 nfa-table get add-transition ;
45 : epsilon-transition ( source target -- )
46 epsilon nfa-table get add-transition ;
48 M:: star nfa-node ( node -- start end )
49 node term>> nfa-node :> s1 :> s0
52 s1 s0 epsilon-transition
53 s2 s0 epsilon-transition
54 s2 s3 epsilon-transition
55 s1 s3 epsilon-transition
58 GENERIC: modify-epsilon ( tag -- newtag )
59 ! Potential off-by-one errors when lookaround nested in lookbehind
61 M: object modify-epsilon ;
64 multiline option? [ drop end-of-input ] unless ;
67 multiline option? [ drop beginning-of-input ] unless ;
69 M: tagged-epsilon nfa-node
70 clone [ modify-epsilon ] change-tag add-simple-entry ;
72 M: concatenation nfa-node ( node -- start end )
73 [ first>> ] [ second>> ] bi
74 reversed-regexp option? [ swap ] when
76 [ epsilon-transition ] dip ;
78 :: alternate-nodes ( s0 s1 s2 s3 -- start end )
81 s4 s0 epsilon-transition
82 s4 s2 epsilon-transition
83 s1 s5 epsilon-transition
84 s3 s5 epsilon-transition
87 M: alternation nfa-node ( node -- start end )
88 [ first>> ] [ second>> ] bi
92 GENERIC: modify-class ( char-class -- char-class' )
94 M: object modify-class ;
96 M: integer modify-class
97 case-insensitive option? [
99 [ ch>lower ] [ ch>upper ] bi 2array <or-class>
103 M: integer nfa-node ( node -- start end )
104 modify-class add-simple-entry ;
106 M: primitive-class modify-class
107 class>> modify-class <primitive-class> ;
109 M: or-class modify-class
110 seq>> [ modify-class ] map <or-class> ;
112 M: not-class modify-class
113 class>> modify-class <not-class> ;
115 M: any-char modify-class
116 drop dotall option? t any-char-no-nl ? ;
118 : modify-letter-class ( class -- newclass )
119 case-insensitive option? [ drop Letter-class ] when ;
120 M: letter-class modify-class modify-letter-class ;
121 M: LETTER-class modify-class modify-letter-class ;
123 : cased-range? ( range -- ? )
124 [ from>> ] [ to>> ] bi {
125 [ [ letter? ] bi@ and ]
126 [ [ LETTER? ] bi@ and ]
129 M: range modify-class
130 case-insensitive option? [
132 [ from>> ] [ to>> ] bi
133 [ [ ch>lower ] bi@ <range> ]
134 [ [ ch>upper ] bi@ <range> ] 2bi
140 modify-class add-simple-entry ;
142 M: with-options nfa-node ( node -- start end )
143 dup options>> [ tree>> nfa-node ] using-options ;
145 : construct-nfa ( ast -- nfa-table )
148 <transition-table> nfa-table set
151 swap dup associate >>final-states