Annotation of gforth/regexp.fs, revision 1.19
1.1 pazsan 1: \ Regexp compile
2:
1.13 anton 3: \ Copyright (C) 2005,2006,2007,2008 Free Software Foundation, Inc.
1.3 anton 4:
5: \ This file is part of Gforth.
6:
7: \ Gforth is free software; you can redistribute it and/or
8: \ modify it under the terms of the GNU General Public License
1.10 anton 9: \ as published by the Free Software Foundation, either version 3
1.3 anton 10: \ of the License, or (at your option) any later version.
11:
12: \ This program is distributed in the hope that it will be useful,
13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: \ GNU General Public License for more details.
16:
17: \ You should have received a copy of the GNU General Public License
1.10 anton 18: \ along with this program. If not, see http://www.gnu.org/licenses/.
1.3 anton 19:
1.1 pazsan 20: \ The idea of the parser is the following:
21: \ As long as there's a match, continue
22: \ On a mismatch, LEAVE.
23: \ Insert appropriate control structures on alternative branches
24: \ Keep the old pointer (backtracking) on the stack
25: \ I try to keep the syntax as close to a real regexp system as possible
26: \ All regexp stuff is compiled into one function as forward branching
27: \ state machine
28:
1.2 pazsan 29: \ special control structure
1.1 pazsan 30:
1.8 pazsan 31: : FORK ( compilation -- orig ; run-time f -- ) \ gforth
32: \G AHEAD-like control structure: calls the code after JOIN.
1.1 pazsan 33: POSTPONE call >mark ; immediate restrict
1.8 pazsan 34: : JOIN ( orig -- ) \ gforth
35: \G THEN-like control structure for FORK
36: postpone THEN ; immediate restrict
1.1 pazsan 37:
38: \ Charclasses
39:
40: : +bit ( addr n -- ) + 1 swap c! ;
41: : -bit ( addr n -- ) + 0 swap c! ;
42: : @+ ( addr -- n addr' ) dup @ swap cell+ ;
43:
44: 0 Value cur-class
1.8 pazsan 45: : charclass ( -- ) \ regexp-cg
46: \G Create a charclass
47: Create here dup to cur-class $100 dup allot erase ;
48: : +char ( char -- ) \ regexp-cg
49: \G add a char to the current charclass
50: cur-class swap +bit ;
51: : -char ( char -- ) \ regexp-cg
52: \G remove a char from the current charclass
53: cur-class swap -bit ;
54: : ..char ( start end -- ) \ regexp-cg
55: \G add a range of chars to the current charclass
56: 1+ swap ?DO I +char LOOP ;
1.1 pazsan 57: : or! ( n addr -- ) dup @ rot or swap ! ;
58: : and! ( n addr -- ) dup @ rot and swap ! ;
1.8 pazsan 59: : +class ( class -- ) \ regexp-cg
60: \G union of charclass @var{class} and the current charclass
61: $100 0 ?DO @+ swap
62: cur-class I + or! cell +LOOP drop ;
63: : -class ( class -- ) \ regexp-cg
64: \G subtract the charclass @var{class} from the current charclass
65: $100 0 ?DO @+ swap invert
66: cur-class I + and! cell +LOOP drop ;
1.1 pazsan 67:
68: : char? ( addr class -- addr' flag )
69: >r count r> + c@ ;
70:
71: \ Charclass tests
72:
1.8 pazsan 73: : c? ( addr class -- ) \ regexp-pattern
74: \G check @var{addr} for membership in charclass @var{class}
75: ]] char? 0= ?LEAVE [[ ; immediate
76: : -c? ( addr class -- ) \ regexp-pattern
77: \G check @var{addr} for not membership in charclass @var{class}
78: ]] char? ?LEAVE [[ ; immediate
1.1 pazsan 79:
80: charclass digit '0 '9 ..char
81: charclass blanks 0 bl ..char
82: \ bl +char #tab +char #cr +char #lf +char ctrl L +char
83: charclass letter 'a 'z ..char 'A 'Z ..char
84: charclass any 0 $FF ..char #lf -char
85:
1.8 pazsan 86: : \d ( addr -- addr' ) \ regexp-pattern
87: \G check for digit
88: ]] digit c? [[ ; immediate
89: : \s ( addr -- addr' ) \ regexp-pattern
90: \G check for blanks
91: ]] blanks c? [[ ; immediate
92: : .? ( addr -- addr' ) \ regexp-pattern
93: \G check for any single charachter
94: ]] any c? [[ ; immediate
95: : -\d ( addr -- addr' ) \ regexp-pattern
96: \G check for not digit
97: ]] digit -c? [[ ; immediate
98: : -\s ( addr -- addr' ) \ regexp-pattern
99: \G check for not blank
100: ]] blanks -c? [[ ; immediate
101: : ` ( "char" -- ) \ regexp-pattern
102: \G check for particular char
1.1 pazsan 103: ]] count [[ char ]] Literal <> ?LEAVE [[ ; immediate
1.17 pazsan 104: : -` ( "char" -- ) \ regexp-pattern
105: \G check for particular char
106: ]] count [[ char ]] Literal = ?LEAVE [[ ; immediate
1.1 pazsan 107:
108: \ loop stack
109:
110: Variable loops $40 3 * cells allot
111: : 3@ ( addr -- a b c ) dup >r 2 cells + @ r> 2@ ;
112: : 3! ( a b c addr -- ) dup >r 2! r> 2 cells + ! ;
113: : loops> ( -- addr ) -3 loops +! loops @+ swap cells + 3@ ;
114: : >loops ( addr -- ) loops @+ swap cells + 3! 3 loops +! ;
115: : BEGIN, ( -- ) ]] BEGIN [[ >loops ;
116: : DONE, ( -- ) loops @ IF loops> ]] DONE [[ THEN ]] noop [[ ;
117:
118: \ variables
119:
120: Variable vars &18 cells allot
121: Variable varstack 9 cells allot
122: Variable varsmax
123: : >var ( -- addr ) vars @+ swap 2* cells +
124: vars @ varstack @+ swap cells + !
125: 1 vars +! 1 varstack +! ;
126: : var> ( -- addr ) -1 varstack +!
127: varstack @+ swap cells + @
128: 1+ 2* cells vars + ;
129:
130: \ start end
131:
132: 0 Value end$
133: 0 Value start$
134: : !end ( addr u -- addr ) over + to end$ dup to start$ ;
1.12 pazsan 135: : end-rex? ( addr -- addr flag ) dup end$ u< ;
136: : start-rex? ( addr -- addr flag ) dup start$ u> ;
1.1 pazsan 137: : ?end ( addr -- addr ) ]] dup end$ u> ?LEAVE [[ ; immediate
138:
139: \ start and end
140:
1.8 pazsan 141: : \^ ( addr -- addr ) \ regexp-pattern
142: \G check for string start
1.12 pazsan 143: ]] start-rex? ?LEAVE [[ ; immediate
1.8 pazsan 144: : \$ ( addr -- addr ) \ regexp-pattern
145: \G check for string end
1.12 pazsan 146: ]] end-rex? ?LEAVE [[ ; immediate
1.1 pazsan 147:
1.17 pazsan 148: \ A word for string comparison
149:
150: : ,=" ( addr u -- ) tuck ]] dup SLiteral tuck compare ?LEAVE Literal + noop [[ ;
151: : =" ( <string>" -- ) \ regexp-pattern
152: \G check for string
153: '" parse ,=" ; immediate
154:
1.1 pazsan 155: \ regexp block
156:
157: \ FORK/JOIN are like AHEAD THEN, but producing a call on AHEAD
158: \ instead of a jump.
159:
1.8 pazsan 160: : (( ( addr u -- ) \ regexp-pattern
161: \G start regexp block
162: vars off varsmax off loops off
1.1 pazsan 163: ]] FORK AHEAD BUT JOIN !end [[ BEGIN, ; immediate
1.8 pazsan 164: : )) ( -- addr f ) \ regexp-pattern
165: \G end regexp block
1.19 ! pazsan 166: ]] ?end drop true ;S [[
! 167: DONE, ]] drop false ;S THEN [[ ; immediate
1.1 pazsan 168:
169: \ greedy loops
170:
171: \ Idea: scan as many characters as possible, try the rest of the pattern
172: \ and then back off one pattern at a time
173:
174: : drops ( n -- ) 1+ cells sp@ + sp! ;
175:
1.8 pazsan 176: : {** ( addr -- addr addr ) \ regexp-pattern
177: \G greedy zero-or-more pattern
1.1 pazsan 178: 0 ]] Literal >r BEGIN dup [[ BEGIN, ; immediate
1.8 pazsan 179: ' {** Alias {++ ( addr -- addr addr ) \ regexp-pattern
180: \G greedy one-or-more pattern
181: immediate
182: : n*} ( sys n -- ) \ regexp-pattern
183: \G At least @var{n} pattern
1.12 pazsan 184: >r ]] r> 1+ >r end-rex? 0= UNTIL dup [[ DONE, ]] drop [[
1.19 ! pazsan 185: r@ IF r@ ]] r@ Literal u< IF r> 1+ drops false ;S THEN [[ THEN
1.1 pazsan 186: r@ ]] r> 1+ Literal U+DO FORK BUT [[
1.19 ! pazsan 187: ]] IF I' I - [[ r@ 1- ]] Literal + drops true UNLOOP ;S THEN LOOP [[
1.1 pazsan 188: r@ IF r@ ]] Literal drops [[ THEN
1.19 ! pazsan 189: rdrop ]] false ;S JOIN [[ ; immediate
1.8 pazsan 190: : **} ( sys -- ) \ regexp-pattern
191: \G end of greedy zero-or-more pattern
192: 0 postpone n*} ; immediate
193: : ++} ( sys -- ) \ regexp-pattern
194: \G end of greedy zero-or-more pattern
195: 1 postpone n*} ; immediate
1.1 pazsan 196:
197: \ non-greedy loops
198:
199: \ Idea: Try to match rest of the regexp, and if that fails, try match
200: \ first expr and then try again rest of regexp.
201:
1.8 pazsan 202: : {+ ( addr -- addr addr ) \ regexp-pattern
203: \G non-greedy one-or-more pattern
1.1 pazsan 204: ]] BEGIN [[ BEGIN, ; immediate
1.8 pazsan 205: : {* ( addr -- addr addr ) \ regexp-pattern
206: \G non-greedy zero-or-more pattern
1.19 ! pazsan 207: ]] {+ dup FORK BUT IF drop true ;S THEN [[ ; immediate
1.8 pazsan 208: : *} ( addr addr' -- addr' ) \ regexp-pattern
209: \G end of non-greedy zero-or-more pattern
1.1 pazsan 210: ]] dup end$ u> UNTIL [[
1.19 ! pazsan 211: DONE, ]] drop false ;S JOIN [[ ; immediate
1.8 pazsan 212: : +} ( addr addr' -- addr' ) \ regexp-pattern
213: \G end of non-greedy one-or-more pattern
1.19 ! pazsan 214: ]] dup FORK BUT IF drop true ;S [[
! 215: DONE, ]] drop false ;S THEN *} [[ ; immediate
1.1 pazsan 216:
1.8 pazsan 217: : // ( -- ) \ regexp-pattern
218: \G search for string
219: ]] {* 1+ *} [[ ; immediate
1.1 pazsan 220:
221: \ alternatives
222:
223: \ idea: try to match one alternative and then the rest of regexp.
224: \ if that fails, jump back to second alternative
225:
1.18 pazsan 226: : JOINs ( sys -- ) BEGIN dup WHILE ]] JOIN [[ REPEAT drop ;
1.1 pazsan 227:
1.8 pazsan 228: : {{ ( addr -- addr addr ) \ regexp-pattern
229: \G Start of alternatives
230: 0 ]] dup BEGIN [[ vars @ ; immediate
231: : || ( addr addr -- addr addr ) \ regexp-pattern
232: \G separator between alternatives
233: vars @ varsmax @ max varsmax !
1.19 ! pazsan 234: ]] dup FORK IF 2drop true ;S THEN drop dup [[ >r >r >r vars !
1.1 pazsan 235: ]] DONE drop dup [[ r> r> r> ]] BEGIN [[ vars @ ; immediate
1.8 pazsan 236: : }} ( addr addr -- addr addr ) \ regexp-pattern
237: \G end of alternatives
238: vars @ varsmax @ max vars !
1.19 ! pazsan 239: ]] dup FORK IF 2drop true ;S THEN drop dup [[ >r >r >r drop
1.18 pazsan 240: ]] DONE drop LEAVE [[ r> r> r> JOINs ; immediate
1.1 pazsan 241:
242: \ match variables
243:
1.8 pazsan 244: : \( ( addr -- addr ) \ regexp-pattern
245: \G start of matching variable; variables are referred as \\1--9
246: ]] dup [[
1.1 pazsan 247: >var ]] ALiteral ! [[ ; immediate
1.8 pazsan 248: : \) ( addr -- addr ) \ regexp-pattern
249: \G end of matching variable
250: ]] dup [[
1.1 pazsan 251: var> ]] ALiteral ! [[ ; immediate
1.8 pazsan 252: : \0 ( -- addr u ) \ regexp-pattern
253: \G the whole string
254: start$ end$ over - ;
1.1 pazsan 255: : \: ( i -- )
256: Create 2* 1+ cells vars + ,
257: DOES> ( -- addr u ) @ 2@ tuck - ;
258: : \:s ( n -- ) 0 ?DO I \: LOOP ;
259: 9 \:s \1 \2 \3 \4 \5 \6 \7 \8 \9
1.6 pazsan 260:
261: \ replacements, needs string.fs
262:
263: require string.fs
264:
265: 0 Value >>ptr
266: 0 Value <<ptr
267: Variable >>string
1.17 pazsan 268: : s>> ( addr -- addr ) \ regexp-replace
1.8 pazsan 269: \G Start replace pattern region
270: dup to >>ptr ;
271: : << ( run-addr addr u -- run-addr ) \ regexp-replace
272: \G Replace string from start of replace pattern region with
273: \G @var{addr} @var{u}
1.6 pazsan 274: <<ptr >>ptr over - >>string $+!
275: >>string $+! dup to <<ptr ;
1.8 pazsan 276: : <<" ( "string<">" -- ) \ regexp-replace
277: \G Replace string from start of replace pattern region with
278: \G @var{string}
279: '" parse postpone SLiteral postpone << ; immediate
1.6 pazsan 280: : >>string@ ( -- addr u )
1.16 pazsan 281: >>string $@ ;
282: : >>string0 ( addr u -- addr u ) s" " >>string $!
283: 0 to >>ptr over to <<ptr ;
1.6 pazsan 284: : >>next ( -- addr u ) <<ptr end$ over - ;
1.14 pazsan 285: : >>rest ( -- ) >>next >>string $+! ;
286: : s// ( addr u -- ptr )
1.8 pazsan 287: \G start search/replace loop
1.17 pazsan 288: ]] >>string0 (( // s>> [[ ; immediate
289: : >> ( addr -- addr )
290: ]] <<ptr >>ptr u> ?LEAVE ?end [[ ; immediate
291: : //s ( ptr -- )
292: \G search end
293: ]] )) drop >>rest >>string@ [[ ; immediate
1.15 pazsan 294: : //o ( ptr addr u -- addr' u' )
1.14 pazsan 295: \G end search/replace single loop
1.17 pazsan 296: ]] << //s [[ ; immediate
1.14 pazsan 297: : //g ( ptr addr u -- addr' u' )
298: \G end search/replace all loop
1.17 pazsan 299: ]] << LEAVE //s [[ ; immediate
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to regexp.fs CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [gforth] / gforth