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authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>2000-12-04 12:43:06 -0200
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>2000-12-04 12:43:06 -0200
commit10ac68c648e0e1d23fe5485bc711df8fc71b6ae3 (patch)
treeda07f262771a48f039049604a2ec3eb0728e4af5 /lstrlib.c
parent01b00cc29261579600ce414b470c339510ac49d5 (diff)
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first implementation for position captures
Diffstat (limited to 'lstrlib.c')
-rw-r--r--lstrlib.c52
1 files changed, 35 insertions, 17 deletions
diff --git a/lstrlib.c b/lstrlib.c
index 5cc0e23b..3eba827d 100644
--- a/lstrlib.c
+++ b/lstrlib.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lstrlib.c,v 1.57 2000/11/23 13:49:35 roberto Exp roberto $ 2** $Id: lstrlib.c,v 1.58 2000/11/24 17:39:56 roberto Exp roberto $
3** Standard library for string operations and pattern-matching 3** Standard library for string operations and pattern-matching
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -123,12 +123,16 @@ static int str_char (lua_State *L) {
123#endif 123#endif
124 124
125 125
126#define CAP_UNFINISHED (-1)
127#define CAP_POSITION (-2)
128
126typedef struct MatchState { 129typedef struct MatchState {
130 const char *src_init; /* init of source string */
127 const char *src_end; /* end ('\0') of source string */ 131 const char *src_end; /* end ('\0') of source string */
128 int level; /* total number of captures (finished or unfinished) */ 132 int level; /* total number of captures (finished or unfinished) */
129 struct { 133 struct {
130 const char *init; 134 const char *init;
131 sint32 len; /* -1 signals unfinished capture */ 135 sint32 len;
132 } capture[MAX_CAPTURES]; 136 } capture[MAX_CAPTURES];
133 lua_State *L; 137 lua_State *L;
134} MatchState; 138} MatchState;
@@ -140,7 +144,7 @@ typedef struct MatchState {
140 144
141static int check_capture (MatchState *ms, int l) { 145static int check_capture (MatchState *ms, int l) {
142 l -= '1'; 146 l -= '1';
143 if (!(0 <= l && l < ms->level && ms->capture[l].len != -1)) 147 if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
144 lua_error(ms->L, "invalid capture index"); 148 lua_error(ms->L, "invalid capture index");
145 return l; 149 return l;
146} 150}
@@ -149,7 +153,7 @@ static int check_capture (MatchState *ms, int l) {
149static int capture_to_close (MatchState *ms) { 153static int capture_to_close (MatchState *ms) {
150 int level = ms->level; 154 int level = ms->level;
151 for (level--; level>=0; level--) 155 for (level--; level>=0; level--)
152 if (ms->capture[level].len == -1) return level; 156 if (ms->capture[level].len == CAP_UNFINISHED) return level;
153 lua_error(ms->L, "invalid pattern capture"); 157 lua_error(ms->L, "invalid pattern capture");
154 return 0; /* to avoid warnings */ 158 return 0; /* to avoid warnings */
155} 159}
@@ -279,14 +283,15 @@ static const char *min_expand (MatchState *ms, const char *s, const char *p,
279} 283}
280 284
281 285
282static const char *start_capture (MatchState *ms, const char *s, const char *p){ 286static const char *start_capture (MatchState *ms, const char *s,
287 const char *p, int what) {
283 const char *res; 288 const char *res;
284 int level = ms->level; 289 int level = ms->level;
285 if (level >= MAX_CAPTURES) lua_error(ms->L, "too many captures"); 290 if (level >= MAX_CAPTURES) lua_error(ms->L, "too many captures");
286 ms->capture[level].init = s; 291 ms->capture[level].init = s;
287 ms->capture[level].len = -1; 292 ms->capture[level].len = what;
288 ms->level = level+1; 293 ms->level = level+1;
289 if ((res=match(ms, s, p+1)) == NULL) /* match failed? */ 294 if ((res=match(ms, s, p)) == NULL) /* match failed? */
290 ms->level--; /* undo capture */ 295 ms->level--; /* undo capture */
291 return res; 296 return res;
292} 297}
@@ -296,8 +301,8 @@ static const char *end_capture (MatchState *ms, const char *s, const char *p) {
296 int l = capture_to_close(ms); 301 int l = capture_to_close(ms);
297 const char *res; 302 const char *res;
298 ms->capture[l].len = s - ms->capture[l].init; /* close capture */ 303 ms->capture[l].len = s - ms->capture[l].init; /* close capture */
299 if ((res = match(ms, s, p+1)) == NULL) /* match failed? */ 304 if ((res = match(ms, s, p)) == NULL) /* match failed? */
300 ms->capture[l].len = -1; /* undo capture */ 305 ms->capture[l].len = CAP_UNFINISHED; /* undo capture */
301 return res; 306 return res;
302} 307}
303 308
@@ -316,9 +321,12 @@ static const char *match (MatchState *ms, const char *s, const char *p) {
316 init: /* using goto's to optimize tail recursion */ 321 init: /* using goto's to optimize tail recursion */
317 switch (*p) { 322 switch (*p) {
318 case '(': /* start capture */ 323 case '(': /* start capture */
319 return start_capture(ms, s, p); 324 if (*(p+1) == ')') /* position capture? */
325 return start_capture(ms, s, p+2, CAP_POSITION);
326 else
327 return start_capture(ms, s, p+1, CAP_UNFINISHED);
320 case ')': /* end capture */ 328 case ')': /* end capture */
321 return end_capture(ms, s, p); 329 return end_capture(ms, s, p+1);
322 case ESC: /* may be %[0-9] or %b */ 330 case ESC: /* may be %[0-9] or %b */
323 if (isdigit((unsigned char)(*(p+1)))) { /* capture? */ 331 if (isdigit((unsigned char)(*(p+1)))) { /* capture? */
324 s = match_capture(ms, s, *(p+1)); 332 s = match_capture(ms, s, *(p+1));
@@ -385,14 +393,21 @@ static const char *lmemfind (const char *s1, size_t l1,
385} 393}
386 394
387 395
396static void push_onecapture (MatchState *ms, int i) {
397 int l = ms->capture[i].len;
398 if (l == CAP_UNFINISHED) lua_error(ms->L, "unfinished capture");
399 if (l == CAP_POSITION)
400 lua_pushnumber(ms->L, ms->capture[i].init - ms->src_init + 1);
401 else
402 lua_pushlstring(ms->L, ms->capture[i].init, l);
403}
404
405
388static int push_captures (MatchState *ms) { 406static int push_captures (MatchState *ms) {
389 int i; 407 int i;
390 luaL_checkstack(ms->L, ms->level, "too many captures"); 408 luaL_checkstack(ms->L, ms->level, "too many captures");
391 for (i=0; i<ms->level; i++) { 409 for (i=0; i<ms->level; i++)
392 int l = ms->capture[i].len; 410 push_onecapture(ms, i);
393 if (l == -1) lua_error(ms->L, "unfinished capture");
394 lua_pushlstring(ms->L, ms->capture[i].init, l);
395 }
396 return ms->level; /* number of strings pushed */ 411 return ms->level; /* number of strings pushed */
397} 412}
398 413
@@ -417,6 +432,7 @@ static int str_find (lua_State *L) {
417 int anchor = (*p == '^') ? (p++, 1) : 0; 432 int anchor = (*p == '^') ? (p++, 1) : 0;
418 const char *s1=s+init; 433 const char *s1=s+init;
419 ms.L = L; 434 ms.L = L;
435 ms.src_init = s;
420 ms.src_end = s+l1; 436 ms.src_end = s+l1;
421 do { 437 do {
422 const char *res; 438 const char *res;
@@ -448,7 +464,8 @@ static void add_s (MatchState *ms, luaL_Buffer *b) {
448 luaL_putchar(b, news[i]); 464 luaL_putchar(b, news[i]);
449 else { 465 else {
450 int level = check_capture(ms, news[i]); 466 int level = check_capture(ms, news[i]);
451 luaL_addlstring(b, ms->capture[level].init, ms->capture[level].len); 467 push_onecapture(ms, level);
468 luaL_addvalue(b); /* add capture to accumulated result */
452 } 469 }
453 } 470 }
454 } 471 }
@@ -480,6 +497,7 @@ static int str_gsub (lua_State *L) {
480 3, "string or function expected"); 497 3, "string or function expected");
481 luaL_buffinit(L, &b); 498 luaL_buffinit(L, &b);
482 ms.L = L; 499 ms.L = L;
500 ms.src_init = src;
483 ms.src_end = src+srcl; 501 ms.src_end = src+srcl;
484 while (n < max_s) { 502 while (n < max_s) {
485 const char *e; 503 const char *e;
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