713 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			Factor
		
	
	
			
		
		
	
	
			713 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			Factor
		
	
	
| ! Copyright (C) 2008 Doug Coleman.
 | |
| ! See http://factorcode.org/license.txt for BSD license.
 | |
| USING: accessors arrays assocs combinators kernel math
 | |
| sequences namespaces locals combinators.lib state-tables
 | |
| math.parser state-parser sets dlists unicode.categories
 | |
| math.order quotations shuffle math.ranges splitting
 | |
| symbols fry parser math.ranges inspector strings ;
 | |
| IN: regexp4
 | |
| 
 | |
| SYMBOLS: eps start-state final-state beginning-of-text
 | |
| end-of-text left-parenthesis alternation left-bracket
 | |
| caret dash ampersand colon ;
 | |
| 
 | |
| SYMBOL: runtime-epsilon
 | |
| 
 | |
| TUPLE: regexp raw parentheses-count bracket-count
 | |
| state stack nfa new-states dfa minimized-dfa
 | |
| dot-matches-newlines? capture-group captured-groups ;
 | |
| 
 | |
| TUPLE: capture-group n range ;
 | |
| 
 | |
| ERROR: parentheses-underflow ;
 | |
| ERROR: unbalanced-parentheses ;
 | |
| ERROR: unbalanced-brackets ;
 | |
| 
 | |
| : push-stack ( regexp token -- ) swap stack>> push ;
 | |
| : push-all-stack ( regexp seq -- ) swap stack>> push-all ;
 | |
| : next-state ( regexp -- n ) [ 1+ ] change-state state>> ;
 | |
| 
 | |
| : check-parentheses-underflow ( regexp -- )
 | |
|     parentheses-count>> 0 < [ parentheses-underflow ] when ;
 | |
| 
 | |
| : check-unbalanced-parentheses ( regexp -- )
 | |
|     parentheses-count>> 0 > [ unbalanced-parentheses ] when ;
 | |
| 
 | |
| :: (apply-alternation) ( stack regexp -- )
 | |
|     [let | s2 [ stack peek first ]
 | |
|            s3 [ stack pop second ]
 | |
|            s0 [ stack peek alternation = [ stack pop* ] when stack peek first ]
 | |
|            s1 [ stack pop second ]
 | |
|            s4 [ regexp next-state ]
 | |
|            s5 [ regexp next-state ]
 | |
|            table [ regexp nfa>> ] |
 | |
|         s5 table add-row
 | |
|         s4 eps s0 <entry> table add-entry
 | |
|         s4 eps s2 <entry> table add-entry
 | |
|         s1 eps s5 <entry> table add-entry
 | |
|         s3 eps s5 <entry> table add-entry
 | |
|         s1 table final-states>> delete-at
 | |
|         s3 table final-states>> delete-at
 | |
|         t s5 table final-states>> set-at
 | |
|         s4 s5 2array stack push ] ;
 | |
| 
 | |
| : apply-alternation ( regexp -- )
 | |
|     [ stack>> ] [ (apply-alternation) ] bi ;
 | |
| 
 | |
| : apply-alternation? ( stack -- ? )
 | |
|     dup length dup 3 <
 | |
|     [ 2drop f ] [ 2 - swap nth alternation = ] if ;
 | |
| 
 | |
| :: (apply-concatenation) ( stack regexp -- )
 | |
|     [let* |
 | |
|             s2 [ stack peek first ]
 | |
|             s3 [ stack pop second ]
 | |
|             s0 [ stack peek first ]
 | |
|             s1 [ stack pop second ]
 | |
|             table [ regexp nfa>> ] |
 | |
|         s1 eps s2 <entry> table set-entry
 | |
|         s1 table final-states>> delete-at
 | |
|         s3 table add-row
 | |
|         s0 s3 2array stack push ] ;
 | |
| 
 | |
| : apply-concatenation ( regexp -- )
 | |
|     [ stack>> ] [ (apply-concatenation) ] bi ;
 | |
| 
 | |
| : apply-concatenation? ( seq -- ? )
 | |
|     dup length dup 2 <
 | |
|     [ 2drop f ] [ 2 - swap nth array? ] if ;
 | |
| 
 | |
| : apply-loop ( seq regexp -- seq regexp )
 | |
|     over length 1 > [
 | |
|         2dup over apply-alternation?
 | |
|         [ (apply-alternation) ] [ (apply-concatenation) ] if apply-loop
 | |
|     ] when ;
 | |
| 
 | |
| : cut-out ( vector n -- vector' vector ) cut rest ;
 | |
| 
 | |
| : cut-stack ( obj vector -- vector' vector )
 | |
|     tuck last-index cut-out swap ;
 | |
|     
 | |
| : apply-til-last ( regexp token -- )
 | |
|     swap [ cut-stack ] change-stack
 | |
|     apply-loop stack>> push-all ;
 | |
| 
 | |
| : concatenation-loop ( regexp -- )
 | |
|     dup stack>> dup apply-concatenation?
 | |
|     [ over (apply-concatenation) concatenation-loop ] [ 2drop ] if ;
 | |
| 
 | |
| :: apply-kleene-closure ( regexp -- )
 | |
|     [let* | stack [ regexp stack>> ]
 | |
|             s0 [ stack peek first ]
 | |
|             s1 [ stack pop second ]
 | |
|             s2 [ regexp next-state ]
 | |
|             s3 [ regexp next-state ]
 | |
|             table [ regexp nfa>> ] |
 | |
|         s1 table final-states>> delete-at
 | |
|         t s3 table final-states>> set-at
 | |
|         s3 table add-row
 | |
|         s1 eps s0 <entry> table add-entry
 | |
|         s2 eps s0 <entry> table add-entry
 | |
|         s2 eps s3 <entry> table add-entry
 | |
|         s1 eps s3 <entry> table add-entry
 | |
|         s2 s3 2array stack push ] ;
 | |
| 
 | |
| : add-numbers ( n obj -- obj )
 | |
|     2dup [ number? ] bi@ and
 | |
|     [ + ] [ dup sequence? [ [ + ] with map ] [ nip ] if ] if ;
 | |
| 
 | |
| : increment-columns ( n assoc -- )
 | |
|     dup [ >r swap >r add-numbers r> r> set-at ] curry with* assoc-each ;
 | |
| 
 | |
| :: copy-state-rows ( regexp range -- )
 | |
|     [let* | len [ range range-length ]
 | |
|             offset [ regexp state>> range range-min - 1+ ]
 | |
|             state [ regexp [ len + ] change-state ] |
 | |
|         regexp nfa>> rows>>
 | |
|         [ drop range member? ] assoc-filter
 | |
|         [
 | |
|             [ offset + ] dip
 | |
|             [ offset swap add-numbers ] assoc-map
 | |
|         ] assoc-map
 | |
|         regexp nfa>> [ assoc-union ] change-rows drop
 | |
|         range [ range-min ] [ range-max ] bi [ offset + ] bi@ 2array
 | |
|         regexp stack>> push ] ;
 | |
| 
 | |
| : last-state ( regexp -- range )
 | |
|     stack>> peek first2 [a,b] ;
 | |
| 
 | |
| : set-last-state-final ( ? regexp -- )
 | |
|     [ stack>> peek second ] [ nfa>> final-states>> ] bi set-at ;
 | |
| 
 | |
| : apply-plus-closure ( regexp -- )
 | |
|     [ dup last-state copy-state-rows ]
 | |
|     [ apply-kleene-closure ]
 | |
|     [ apply-concatenation ] tri ;
 | |
| 
 | |
| : apply-question-closure ( regexp -- )
 | |
|     [ stack>> peek first2 eps swap <entry> ] [ nfa>> add-entry ] bi ;
 | |
| 
 | |
| : with0 ( obj n quot -- n quot' ) swapd curry ; inline
 | |
| 
 | |
| 
 | |
| : range>state ( range -- pair )
 | |
|     [ from>> ] [ length>> ] bi over - 2array ;
 | |
| 
 | |
| : copy-state ( regexp range n -- )
 | |
|     dup zero? [
 | |
|         drop range>state over stack>> push apply-question-closure
 | |
|     ] [
 | |
|         [ copy-state-rows ] with0 with0 times
 | |
|     ] if ;
 | |
| 
 | |
| :: (exactly-n) ( regexp state n -- )
 | |
|     regexp state n copy-state
 | |
|     t regexp set-last-state-final ;
 | |
| 
 | |
| : exactly-n ( regexp n -- )
 | |
|     >r dup last-state r> 1- (exactly-n) ;
 | |
| 
 | |
| : exactly-n-concatenated ( regexp state n -- )
 | |
| B
 | |
|     [ (exactly-n) ] 3keep
 | |
|     nip 1- [ apply-concatenation ] with0 times ;
 | |
| 
 | |
| :: at-least-n ( regexp n -- )
 | |
|     [let | state [ regexp stack>> pop first2 [a,b] ] |
 | |
|         regexp state n copy-state
 | |
|         state regexp stack>> push
 | |
|         regexp apply-kleene-closure ] ; 
 | |
| 
 | |
| : peek-last ( regexp -- range )
 | |
|     stack>> peek first2 [a,b] ;
 | |
| 
 | |
| : pop-last ( regexp -- range )
 | |
|     stack>> pop first2 [a,b] ;
 | |
| 
 | |
| :: at-most-n ( regexp n -- )
 | |
|     [let | state [ regexp pop-last ] |
 | |
|         regexp state n [ 1+ exactly-n-concatenated ] with with each
 | |
|         regexp n 1- [ apply-alternation ] with0 times
 | |
|         regexp apply-question-closure ] ;
 | |
| 
 | |
| :: from-m-to-n ( regexp m n -- )
 | |
|     [let | state [ regexp pop-last ] |
 | |
|         regexp state
 | |
|         m n [a,b] [ exactly-n-concatenated ] with with each
 | |
|         regexp n m - [ apply-alternation ] with0 times ] ;
 | |
| 
 | |
| : apply-brace-closure ( regexp from/f to/f comma? -- )
 | |
|     [
 | |
|         2dup and
 | |
|         [ from-m-to-n ]
 | |
|         [ [ nip at-most-n ] [ at-least-n ] if* ] if
 | |
|     ] [ drop exactly-n ] if ;
 | |
| 
 | |
| :: push-single-nfa ( regexp obj -- )
 | |
|     [let | s0 [ regexp next-state ]
 | |
|            s1 [ regexp next-state ]
 | |
|            stack [ regexp stack>> ]
 | |
|            table [ regexp nfa>> ] |
 | |
|         s0 obj s1 <entry> table set-entry
 | |
|         s1 table add-row
 | |
|         t s1 table final-states>> set-at
 | |
|         s0 s1 2array stack push ] ;
 | |
| 
 | |
| : set-start-state ( regexp -- )
 | |
|     dup stack>> dup empty? [
 | |
|         2drop
 | |
|     ] [
 | |
|         [ nfa>> ] [ pop first ] bi* >>start-state drop
 | |
|     ] if ;
 | |
| 
 | |
| : ascii? ( n -- ? ) 0 HEX: 7f between? ;
 | |
| : octal-digit? ( n -- ? ) CHAR: 0 CHAR: 7 between? ;
 | |
| : decimal-digit? ( n -- ? ) CHAR: 0 CHAR: 9 between? ;
 | |
| 
 | |
| : hex-digit? ( n -- ? )
 | |
|     [
 | |
|         [ dup decimal-digit? ]
 | |
|         [ dup CHAR: a CHAR: f between? ]
 | |
|         [ dup CHAR: A CHAR: F between? ]
 | |
|     ] || nip ;
 | |
| 
 | |
| : control-char? ( n -- ? )
 | |
|     [
 | |
|         [ dup 0 HEX: 1f between? ]
 | |
|         [ dup HEX: 7f = ]
 | |
|     ] || nip ;
 | |
| 
 | |
| : punct? ( n -- ? )
 | |
|     "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~" member? ;
 | |
| 
 | |
| : c-identifier-char? ( ch -- ? ) 
 | |
|     [ [ dup alpha? ] [ dup CHAR: _ = ] ] || nip ;
 | |
| 
 | |
| : java-blank? ( n -- ? )
 | |
|     {   
 | |
|         CHAR: \s CHAR: \t CHAR: \n
 | |
|         HEX: b HEX: 7 CHAR: \r
 | |
|     } member? ;
 | |
| 
 | |
| : java-printable? ( n -- ? )
 | |
|     [ [ dup alpha? ] [ dup punct? ] ] || nip ;
 | |
| 
 | |
| ERROR: bad-character-class obj ;
 | |
| 
 | |
| : parse-posix-class ( -- quot )
 | |
|     next
 | |
|     CHAR: { expect
 | |
|     [ get-char CHAR: } = ] take-until
 | |
|     {
 | |
|         { "Lower" [ [ letter? ] ] }
 | |
|         { "Upper" [ [ LETTER? ] ] }
 | |
|         { "ASCII" [ [ ascii? ] ] }
 | |
|         { "Alpha" [ [ Letter? ] ] }
 | |
|         { "Digit" [ [ digit? ] ] }
 | |
|         { "Alnum" [ [ alpha? ] ] }
 | |
|         { "Punct" [ [ punct? ] ] }
 | |
|         { "Graph" [ [ java-printable? ] ] }
 | |
|         { "Print" [ [ java-printable? ] ] }
 | |
|         { "Blank" [ [ " \t" member? ] ] }
 | |
|         { "Cntrl" [ [ control-char? ] ] }
 | |
|         { "XDigit" [ [ hex-digit? ] ] }
 | |
|         { "Space" [ [ java-blank? ] ] }
 | |
|         ! TODO: unicode-character-class, fallthrough in unicode is bad-char-clss
 | |
|         [ bad-character-class ]
 | |
|     } case ;
 | |
| 
 | |
| ERROR: bad-octal number ;
 | |
| 
 | |
| : parse-octal ( -- n )
 | |
|     next get-char drop
 | |
|     3 take oct>
 | |
|     dup 255 > [ bad-octal ] when ;
 | |
| 
 | |
| ERROR: bad-hex number ;
 | |
| 
 | |
| : parse-short-hex ( -- n )
 | |
|     next 2 take hex>
 | |
|     dup number? [ bad-hex ] unless ;
 | |
| 
 | |
| : parse-long-hex ( -- n )
 | |
|     next 6 take hex>
 | |
|     dup number? [ bad-hex ] unless ;
 | |
| 
 | |
| : parse-control-character ( -- n )
 | |
|     next get-char ;
 | |
| 
 | |
| : dot-construction ( regexp -- )
 | |
|     [ CHAR: \n = not ] push-single-nfa ;
 | |
| 
 | |
| : front-anchor-construction ( regexp -- )
 | |
|     drop ;
 | |
| 
 | |
| : back-anchor-construction  ( regexp -- )
 | |
|     drop ;
 | |
| 
 | |
| : parse-brace ( -- from/f to/f comma? )
 | |
|     next
 | |
|     [ get-char CHAR: } = ] take-until
 | |
|     "," split1 [ [ string>number ] bi@ ] keep >boolean ;
 | |
| 
 | |
| TUPLE: character-class members ;
 | |
| TUPLE: character-class-range from to ;
 | |
| TUPLE: negated-character-class < character-class ;
 | |
| TUPLE: negated-character-class-range < character-class-range ;
 | |
| TUPLE: intersection-class < character-class ;
 | |
| TUPLE: negated-intersection-class < intersection-class ;
 | |
| 
 | |
| GENERIC: character-class-contains? ( obj character-class -- ? )
 | |
| 
 | |
| : parse-escaped-until ( -- seq )
 | |
|     [ get-char CHAR: \ = get-next CHAR: E = and ] take-until
 | |
|     next ;
 | |
| 
 | |
| : character-class-predicate ( seq -- quot )
 | |
|     boa '[ , character-class-contains? ] ;
 | |
| 
 | |
| ERROR: unmatched-escape-sequence ;
 | |
| 
 | |
| : (parse-escaped) ( regexp ? ch -- obj )
 | |
|     {
 | |
|         { CHAR: \ [ [ CHAR: \ = ] ] }
 | |
|         { CHAR: t [ [ CHAR: \t = ] ] }
 | |
|         { CHAR: n [ [ CHAR: \n = ] ] }
 | |
|         { CHAR: r [ [ CHAR: \r = ] ] }
 | |
|         { CHAR: f [ [ HEX: c = ] ] }
 | |
|         { CHAR: a [ [ HEX: 7 = ] ] }
 | |
|         { CHAR: e [ [ HEX: 1b = ] ] }
 | |
| 
 | |
|         { CHAR: d [ [ digit? ] ] }
 | |
|         { CHAR: D [ [ digit? not ] ] }
 | |
|         { CHAR: s [ [ java-blank? ] ] }
 | |
|         { CHAR: S [ [ java-blank? not ] ] }
 | |
|         { CHAR: w [ [ c-identifier-char? ] ] }
 | |
|         { CHAR: W [ [ c-identifier-char? not ] ] }
 | |
| 
 | |
|         { CHAR: p [ parse-posix-class ] }
 | |
|         { CHAR: P [ parse-posix-class [ not ] compose ] }
 | |
|         { CHAR: x [ parse-short-hex ] }
 | |
|         { CHAR: u [ parse-long-hex ] }
 | |
|         { CHAR: 0 [ parse-octal ] }
 | |
|         { CHAR: c [ parse-control-character ] }
 | |
| 
 | |
|         ! { CHAR: Q [ next parse-escaped-until ] }
 | |
|         ! { CHAR: E [ unmatched-escape-sequence ] }
 | |
| 
 | |
|         ! { CHAR: b [ ] } ! a word boundary
 | |
|         ! { CHAR: B [ ] } ! a non-word boundary
 | |
|         ! { CHAR: A [ ] } ! beginning of input
 | |
|         ! { CHAR: G [ ] } ! end of previous match
 | |
|         ! { CHAR: Z [ ] } ! end of input but for the final terminator, if any
 | |
|         ! { CHAR: z [ ] } ! end of the input
 | |
|         [ ]
 | |
|     } case ;
 | |
| 
 | |
| : parse-escaped ( regexp -- )
 | |
|     next get-char (parse-escaped) push-single-nfa ;
 | |
| 
 | |
| : handle-dash ( vector -- vector )
 | |
|     [ dup dash eq? [ drop CHAR: - ] when ] map ;
 | |
| 
 | |
| M: object character-class-contains? ( obj1 obj2 -- ? )
 | |
|     = ;
 | |
| 
 | |
| M: callable character-class-contains? ( obj1 callable -- ? )
 | |
|     call ;
 | |
| 
 | |
| M: character-class character-class-contains? ( obj cc -- ? )
 | |
|     members>> [ character-class-contains? ] with find drop >boolean ;
 | |
| 
 | |
| M: negated-character-class character-class-contains? ( obj cc -- ? )
 | |
|     call-next-method not ;
 | |
| 
 | |
| M: character-class-range character-class-contains? ( obj cc -- ? )
 | |
|     [ from>> ] [ to>> ] bi between?  ;
 | |
| 
 | |
| M: negated-character-class-range character-class-contains? ( obj cc -- ? )
 | |
|     call-next-method not ;
 | |
| 
 | |
| M: intersection-class character-class-contains? ( obj cc -- ? )
 | |
|     members>> [ character-class-contains? not ] with find drop not ;
 | |
| 
 | |
| M: negated-intersection-class character-class-contains? ( obj cc -- ? )
 | |
|     call-next-method not ;
 | |
| 
 | |
| ERROR: unmatched-negated-character-class class ;
 | |
| 
 | |
| : handle-caret ( obj -- seq class )
 | |
|     dup [ length 2 >= ] [ first caret eq? ] bi and [ 
 | |
|         rest negated-character-class
 | |
|     ] [
 | |
|         character-class
 | |
|     ] if ;
 | |
| 
 | |
| : make-character-class ( regexp -- )
 | |
|     left-bracket over stack>> cut-stack
 | |
|     pick (>>stack)
 | |
|     handle-dash handle-caret
 | |
|     character-class-predicate push-single-nfa ;
 | |
| 
 | |
| : apply-dash ( regexp -- )
 | |
|     stack>> dup [ pop ] [ pop* ] [ pop ] tri
 | |
|     swap character-class-range boa swap push ;
 | |
| 
 | |
| : apply-dash? ( regexp -- ? )
 | |
|     stack>> dup length 3 >=
 | |
|     [ [ length 2 - ] keep nth dash eq? ] [ drop f ] if ;
 | |
| 
 | |
| DEFER: parse-character-class
 | |
| : (parse-character-class) ( regexp -- )
 | |
|     [
 | |
|         next get-char
 | |
|         {
 | |
|             { CHAR: [ [
 | |
|                 [ 1+ ] change-bracket-count dup left-bracket push-stack
 | |
|                 parse-character-class
 | |
|             ] }
 | |
|             { CHAR: ] [
 | |
|                 [ 1- ] change-bracket-count
 | |
|                 make-character-class
 | |
|             ] }
 | |
|             { CHAR: - [ dash push-stack ] }
 | |
|             ! { CHAR: & [ ampersand push-stack ] }
 | |
|             ! { CHAR: : [ semicolon push-stack ] }
 | |
|             { CHAR: \ [ next get-char (parse-escaped) push-stack ] }
 | |
|             { f [ unbalanced-brackets ] }
 | |
|             [ dupd push-stack dup apply-dash? [ apply-dash ] [ drop ] if ]
 | |
|         } case
 | |
|     ] [
 | |
|         dup bracket-count>> 0 >
 | |
|         [ (parse-character-class) ] [ drop ] if
 | |
|     ] bi ;
 | |
| 
 | |
| : parse-character-class-second ( regexp -- )
 | |
|     get-next
 | |
|     {
 | |
|         { CHAR: [ [ CHAR: [ push-stack next ] }
 | |
|         { CHAR: ] [ CHAR: ] push-stack next ] }
 | |
|         { CHAR: - [ CHAR: - push-stack next ] }
 | |
|         [ 2drop ]
 | |
|     } case ;
 | |
| 
 | |
| : parse-character-class-first ( regexp -- )
 | |
|     get-next
 | |
|     {
 | |
|         { CHAR: ^ [ caret dupd push-stack next parse-character-class-second ] }
 | |
|         { CHAR: [ [ CHAR: [ push-stack next ] }
 | |
|         { CHAR: ] [ CHAR: ] push-stack next ] }
 | |
|         { CHAR: - [ CHAR: - push-stack next ] }
 | |
|         [ 2drop ]
 | |
|     } case ;
 | |
| 
 | |
| : parse-character-class ( regexp -- )
 | |
|     [ parse-character-class-first ] [ (parse-character-class) ] bi ;
 | |
| 
 | |
| ERROR: unsupported-token token ;
 | |
| : parse-token ( regexp token -- )
 | |
|     dup {
 | |
|         { CHAR: ^ [ drop front-anchor-construction ] }
 | |
|         { CHAR: $ [ drop back-anchor-construction ] }
 | |
|         { CHAR: \ [ drop parse-escaped ] }
 | |
|         { CHAR: | [ drop dup concatenation-loop alternation push-stack ] }
 | |
|         { CHAR: ( [ drop [ 1+ ] change-parentheses-count left-parenthesis push-stack ] }
 | |
|         { CHAR: ) [ drop [ 1- ] change-parentheses-count left-parenthesis apply-til-last ] }
 | |
|         { CHAR: * [ drop apply-kleene-closure ] }
 | |
|         { CHAR: + [ drop apply-plus-closure ] }
 | |
|         { CHAR: ? [ drop apply-question-closure ] }
 | |
|         { CHAR: { [ drop parse-brace apply-brace-closure ] }
 | |
|         { CHAR: [ [
 | |
|             drop
 | |
|             dup left-bracket push-stack
 | |
|             [ 1+ ] change-bracket-count parse-character-class
 | |
|         ] }
 | |
|         ! { CHAR: } [ drop drop "brace" ] }
 | |
|         { CHAR: . [ drop dot-construction ] }
 | |
|         { beginning-of-text [ push-stack ] }
 | |
|         { end-of-text [
 | |
|             drop {
 | |
|                 [ check-unbalanced-parentheses ]
 | |
|                 [ concatenation-loop ]
 | |
|                 [ beginning-of-text apply-til-last ]
 | |
|                 [ set-start-state ]
 | |
|             } cleave
 | |
|         ] }
 | |
|         [ drop push-single-nfa ]
 | |
|     } case ;
 | |
| 
 | |
| : (parse-raw-regexp) ( regexp -- )
 | |
|     get-char [ dupd parse-token next (parse-raw-regexp) ] [ drop ] if* ;
 | |
| 
 | |
| : parse-raw-regexp ( regexp -- )
 | |
|     [ beginning-of-text parse-token ]
 | |
|     [
 | |
|         dup raw>> dup empty? [
 | |
|             2drop
 | |
|         ] [
 | |
|             [ (parse-raw-regexp) ] string-parse
 | |
|         ] if
 | |
|     ]
 | |
|     [ end-of-text parse-token ] tri ;
 | |
| 
 | |
| :: find-delta ( states obj table -- keys )
 | |
|     obj states [
 | |
|         table get-row at
 | |
|         [ dup integer? [ 1array ] when unique ] [ H{ } ] if*
 | |
|     ] with map H{ } clone [ assoc-union ] reduce keys ;
 | |
| 
 | |
| :: (find-closure) ( states obj assoc table -- keys )
 | |
|     [let | size [ assoc assoc-size ] |
 | |
|         assoc states unique assoc-union
 | |
|         dup assoc-size size > [
 | |
|             obj states [
 | |
|                 table get-row at* [
 | |
|                     dup integer? [ 1array ] when
 | |
|                     obj rot table (find-closure)
 | |
|                 ] [
 | |
|                     drop
 | |
|                 ] if
 | |
|             ] with each
 | |
|         ] when ] ;
 | |
| 
 | |
| : find-closure ( states obj table -- states )
 | |
|     >r H{ } r> (find-closure) keys ;
 | |
| 
 | |
| : find-epsilon-closure ( states table -- states )
 | |
|     >r eps H{ } r> (find-closure) keys ;
 | |
| 
 | |
| : filter-special-transition ( vec -- vec' )
 | |
|     [ drop eps = not ] assoc-filter ;
 | |
| 
 | |
| : initialize-subset-construction ( regexp -- )
 | |
|     <vector-table> >>dfa
 | |
|     [
 | |
|         nfa>> [ start-state>> 1array ] keep
 | |
|         find-epsilon-closure 1dlist
 | |
|     ] [
 | |
|         swap >>new-states drop
 | |
|     ] [
 | |
|         [ dfa>> ] [ nfa>> ] bi
 | |
|         columns>> filter-special-transition >>columns drop
 | |
|     ] tri ;
 | |
| 
 | |
| :: (subset-construction) ( regexp -- )
 | |
|     [let* | nfa [ regexp nfa>> ]
 | |
|            dfa [ regexp dfa>> ]
 | |
|            new-states [ regexp new-states>> ]
 | |
|            columns [ dfa columns>> keys ] |
 | |
|         
 | |
|         new-states dlist-empty? [
 | |
|             new-states pop-front
 | |
|             dup dfa add-row
 | |
|             columns [
 | |
|                 2dup nfa [ find-delta ] [ find-epsilon-closure ] bi
 | |
|                 dup [ dfa rows>> key? ] [ empty? ] bi or [
 | |
|                     dup new-states push-back
 | |
|                 ] unless
 | |
|                 dup empty? [ 3drop ] [ <entry> dfa set-entry ] if
 | |
|             ] with each
 | |
|             regexp (subset-construction)
 | |
|         ] unless ] ;
 | |
| 
 | |
| : set-start/final-states ( regexp -- )
 | |
|     dup [ nfa>> start-state>> ]
 | |
|     [ dfa>> rows>> keys [ member? ] with filter first ] bi
 | |
|     >r dup dfa>> r> >>start-state drop
 | |
| 
 | |
|     dup [ nfa>> final-states>> ] [ dfa>> rows>> ] bi
 | |
|     [ keys ] bi@
 | |
|     [ intersect empty? not ] with filter
 | |
|     >r dfa>> r> >>final-states drop ;
 | |
| 
 | |
| : subset-construction ( regexp -- )
 | |
|     [ initialize-subset-construction ]
 | |
|     [ (subset-construction) ]
 | |
|     [ set-start/final-states ] tri ;
 | |
| 
 | |
| : <regexp> ( raw -- obj )
 | |
|     regexp new
 | |
|         swap >>raw
 | |
|         0 >>parentheses-count
 | |
|         0 >>bracket-count
 | |
|         -1 >>state
 | |
|         V{ } clone >>stack 
 | |
|         <vector-table> >>nfa
 | |
|         dup [ parse-raw-regexp ] [ subset-construction ] bi ;
 | |
| 
 | |
| ! Literal syntax for regexps
 | |
| : parse-options ( string -- ? )
 | |
|     #! Lame
 | |
|     {
 | |
|         { "" [ f ] }
 | |
|         { "i" [ t ] }
 | |
|     } case ;
 | |
| 
 | |
| : parse-regexp ( accum end -- accum )
 | |
|     lexer get dup skip-blank
 | |
|     [ [ index-from dup 1+ swap ] 2keep swapd subseq swap ] change-lexer-column
 | |
|     ! lexer get dup still-parsing-line?
 | |
|     ! [ (parse-token) parse-options ] [ drop f ] if
 | |
|     <regexp> parsed ;
 | |
| 
 | |
| : R! CHAR: ! parse-regexp ; parsing
 | |
| : R" CHAR: " parse-regexp ; parsing
 | |
| : R# CHAR: # parse-regexp ; parsing
 | |
| : R' CHAR: ' parse-regexp ; parsing
 | |
| : R( CHAR: ) parse-regexp ; parsing
 | |
| : R/ CHAR: / parse-regexp ; parsing
 | |
| : R@ CHAR: @ parse-regexp ; parsing
 | |
| : R[ CHAR: ] parse-regexp ; parsing
 | |
| : R` CHAR: ` parse-regexp ; parsing
 | |
| : R{ CHAR: } parse-regexp ; parsing
 | |
| : R| CHAR: | parse-regexp ; parsing
 | |
| 
 | |
| TUPLE: dfa-traverser
 | |
|     dfa
 | |
|     last-state current-state
 | |
|     text
 | |
|     start-index current-index
 | |
|     matches ;
 | |
| 
 | |
| : <dfa-traverser> ( text dfa -- match )
 | |
|     dfa>>
 | |
|     dfa-traverser new
 | |
|         swap [ start-state>> >>current-state ] keep
 | |
|         >>dfa
 | |
|         swap >>text
 | |
|         0 >>start-index
 | |
|         0 >>current-index
 | |
|         V{ } clone >>matches ;
 | |
| 
 | |
| : final-state? ( dfa-traverser -- ? )
 | |
|     [ current-state>> ] [ dfa>> final-states>> ] bi
 | |
|     member? ;
 | |
| 
 | |
| : 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>
 | |
|     >>current-state ;
 | |
| 
 | |
| : match-transition ( obj hash -- state/f )
 | |
|     2dup keys [ callable? ] filter predicates
 | |
|     [ swap at nip ] [ at ] if* ;
 | |
| 
 | |
| : do-match ( dfa-traverser -- dfa-traverser )
 | |
|     dup match-done? [
 | |
|         dup {
 | |
|             [ current-index>> ]
 | |
|             [ text>> ]
 | |
|             [ current-state>> ]
 | |
|             [ dfa>> rows>> ]
 | |
|         } cleave
 | |
|         at >r nth r> match-transition [
 | |
|             increment-state do-match
 | |
|         ] when*
 | |
|     ] unless ;
 | |
| 
 | |
| : return-match ( dfa-traverser -- interval/f )
 | |
|     dup matches>> empty? [
 | |
|         drop f
 | |
|     ] [
 | |
|         [ start-index>> ] [ matches>> peek ] bi 1 <range>
 | |
|     ] if ;
 | |
| 
 | |
| : match ( string regexp -- pair )
 | |
|     <dfa-traverser> do-match return-match ;
 | |
| 
 | |
| : matches? ( string regexp -- ? )
 | |
|     dupd match [ [ length ] [ range-length 1- ] bi* = ] [ drop f ] if* ;
 | |
| 
 | |
| : match-head ( string regexp -- end )
 | |
|     match length>> 1- ;
 | |
| 
 | |
| ! character classes
 | |
| ! TUPLE: range-class from to ;
 | |
| ! TUPLE: or-class left right ;
 | |
| 
 | |
| ! (?:a|b)*  <- does not capture
 | |
| ! (a|b)*\1  <- group captured
 | |
| ! doesn't advance the current position:
 | |
| ! (?=abba)  positive lookahead  matches abbaaa but not abaaa
 | |
| ! (?!abba)  negative lookahead  matches ababa but not abbaa
 | |
| ! look behind.   "lookaround"
 | |
| 
 | |
| ! : $ ( n -- obj ) groups get nth ;
 | |
| ! [
 | |
|     ! groups bound to scope here
 | |
| ! ] [
 | |
|     ! error or something
 | |
| ! ] if-match
 | |
| ! match in a string with  .*foo.*
 |