commit 10ac68c648e0e1d23fe5485bc711df8fc71b6ae3
parent 01b00cc29261579600ce414b470c339510ac49d5
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 4 Dec 2000 12:42:44 -0200
first implementation for position captures
Diffstat:
M | lstrlib.c | | | 52 | +++++++++++++++++++++++++++++++++++----------------- |
1 file changed, 35 insertions(+), 17 deletions(-)
diff --git a/lstrlib.c b/lstrlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstrlib.c,v 1.57 2000/11/23 13:49:35 roberto Exp roberto $
+** $Id: lstrlib.c,v 1.58 2000/11/24 17:39:56 roberto Exp roberto $
** Standard library for string operations and pattern-matching
** See Copyright Notice in lua.h
*/
@@ -123,12 +123,16 @@ static int str_char (lua_State *L) {
#endif
+#define CAP_UNFINISHED (-1)
+#define CAP_POSITION (-2)
+
typedef struct MatchState {
+ const char *src_init; /* init of source string */
const char *src_end; /* end ('\0') of source string */
int level; /* total number of captures (finished or unfinished) */
struct {
const char *init;
- sint32 len; /* -1 signals unfinished capture */
+ sint32 len;
} capture[MAX_CAPTURES];
lua_State *L;
} MatchState;
@@ -140,7 +144,7 @@ typedef struct MatchState {
static int check_capture (MatchState *ms, int l) {
l -= '1';
- if (!(0 <= l && l < ms->level && ms->capture[l].len != -1))
+ if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
lua_error(ms->L, "invalid capture index");
return l;
}
@@ -149,7 +153,7 @@ static int check_capture (MatchState *ms, int l) {
static int capture_to_close (MatchState *ms) {
int level = ms->level;
for (level--; level>=0; level--)
- if (ms->capture[level].len == -1) return level;
+ if (ms->capture[level].len == CAP_UNFINISHED) return level;
lua_error(ms->L, "invalid pattern capture");
return 0; /* to avoid warnings */
}
@@ -279,14 +283,15 @@ static const char *min_expand (MatchState *ms, const char *s, const char *p,
}
-static const char *start_capture (MatchState *ms, const char *s, const char *p){
+static const char *start_capture (MatchState *ms, const char *s,
+ const char *p, int what) {
const char *res;
int level = ms->level;
if (level >= MAX_CAPTURES) lua_error(ms->L, "too many captures");
ms->capture[level].init = s;
- ms->capture[level].len = -1;
+ ms->capture[level].len = what;
ms->level = level+1;
- if ((res=match(ms, s, p+1)) == NULL) /* match failed? */
+ if ((res=match(ms, s, p)) == NULL) /* match failed? */
ms->level--; /* undo capture */
return res;
}
@@ -296,8 +301,8 @@ static const char *end_capture (MatchState *ms, const char *s, const char *p) {
int l = capture_to_close(ms);
const char *res;
ms->capture[l].len = s - ms->capture[l].init; /* close capture */
- if ((res = match(ms, s, p+1)) == NULL) /* match failed? */
- ms->capture[l].len = -1; /* undo capture */
+ if ((res = match(ms, s, p)) == NULL) /* match failed? */
+ ms->capture[l].len = CAP_UNFINISHED; /* undo capture */
return res;
}
@@ -316,9 +321,12 @@ static const char *match (MatchState *ms, const char *s, const char *p) {
init: /* using goto's to optimize tail recursion */
switch (*p) {
case '(': /* start capture */
- return start_capture(ms, s, p);
+ if (*(p+1) == ')') /* position capture? */
+ return start_capture(ms, s, p+2, CAP_POSITION);
+ else
+ return start_capture(ms, s, p+1, CAP_UNFINISHED);
case ')': /* end capture */
- return end_capture(ms, s, p);
+ return end_capture(ms, s, p+1);
case ESC: /* may be %[0-9] or %b */
if (isdigit((unsigned char)(*(p+1)))) { /* capture? */
s = match_capture(ms, s, *(p+1));
@@ -385,14 +393,21 @@ static const char *lmemfind (const char *s1, size_t l1,
}
+static void push_onecapture (MatchState *ms, int i) {
+ int l = ms->capture[i].len;
+ if (l == CAP_UNFINISHED) lua_error(ms->L, "unfinished capture");
+ if (l == CAP_POSITION)
+ lua_pushnumber(ms->L, ms->capture[i].init - ms->src_init + 1);
+ else
+ lua_pushlstring(ms->L, ms->capture[i].init, l);
+}
+
+
static int push_captures (MatchState *ms) {
int i;
luaL_checkstack(ms->L, ms->level, "too many captures");
- for (i=0; i<ms->level; i++) {
- int l = ms->capture[i].len;
- if (l == -1) lua_error(ms->L, "unfinished capture");
- lua_pushlstring(ms->L, ms->capture[i].init, l);
- }
+ for (i=0; i<ms->level; i++)
+ push_onecapture(ms, i);
return ms->level; /* number of strings pushed */
}
@@ -417,6 +432,7 @@ static int str_find (lua_State *L) {
int anchor = (*p == '^') ? (p++, 1) : 0;
const char *s1=s+init;
ms.L = L;
+ ms.src_init = s;
ms.src_end = s+l1;
do {
const char *res;
@@ -448,7 +464,8 @@ static void add_s (MatchState *ms, luaL_Buffer *b) {
luaL_putchar(b, news[i]);
else {
int level = check_capture(ms, news[i]);
- luaL_addlstring(b, ms->capture[level].init, ms->capture[level].len);
+ push_onecapture(ms, level);
+ luaL_addvalue(b); /* add capture to accumulated result */
}
}
}
@@ -480,6 +497,7 @@ static int str_gsub (lua_State *L) {
3, "string or function expected");
luaL_buffinit(L, &b);
ms.L = L;
+ ms.src_init = src;
ms.src_end = src+srcl;
while (n < max_s) {
const char *e;