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patterns now accept '\0' as a regular character

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Roberto Ierusalimschy 2010-04-12 09:00:50 -03:00
parent 9100f7479a
commit 4541243355
1 changed files with 38 additions and 28 deletions
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66
lstrlib.c
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@ -1,5 +1,5 @@
/* /*
** $Id: lstrlib.c,v 1.148 2010/01/04 16:37:19 roberto Exp roberto $ ** $Id: lstrlib.c,v 1.149 2010/04/09 16:14:46 roberto Exp roberto $
** Standard library for string operations and pattern-matching ** Standard library for string operations and pattern-matching
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@ -180,7 +180,8 @@ static int str_dump (lua_State *L) {
typedef struct MatchState { typedef struct MatchState {
const char *src_init; /* init of source string */ const char *src_init; /* init of source string */
const char *src_end; /* end (`\0') of source string */ const char *src_end; /* end ('\0') of source string */
const char *p_end; /* end ('\0') of pattern */
lua_State *L; lua_State *L;
int level; /* total number of captures (finished or unfinished) */ int level; /* total number of captures (finished or unfinished) */
struct { struct {
@ -213,16 +214,16 @@ static int capture_to_close (MatchState *ms) {
static const char *classend (MatchState *ms, const char *p) { static const char *classend (MatchState *ms, const char *p) {
switch (*p++) { switch (*p++) {
case L_ESC: { case L_ESC: {
if (*p == '\0') if (p == ms->p_end)
luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")"); luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")");
return p+1; return p+1;
} }
case '[': { case '[': {
if (*p == '^') p++; if (*p == '^') p++;
do { /* look for a `]' */ do { /* look for a `]' */
if (*p == '\0') if (p == ms->p_end)
luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")"); luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")");
if (*(p++) == L_ESC && *p != '\0') if (*(p++) == L_ESC && p < ms->p_end)
p++; /* skip escapes (e.g. `%]') */ p++; /* skip escapes (e.g. `%]') */
} while (*p != ']'); } while (*p != ']');
return p+1; return p+1;
@ -246,7 +247,7 @@ static int match_class (int c, int cl) {
case 'u' : res = isupper(c); break; case 'u' : res = isupper(c); break;
case 'w' : res = isalnum(c); break; case 'w' : res = isalnum(c); break;
case 'x' : res = isxdigit(c); break; case 'x' : res = isxdigit(c); break;
case 'z' : res = (c == 0); break; case 'z' : res = (c == 0); break; /* deprecated option */
default: return (cl == c); default: return (cl == c);
} }
return (islower(cl) ? res : !res); return (islower(cl) ? res : !res);
@ -291,8 +292,9 @@ static const char *match (MatchState *ms, const char *s, const char *p);
static const char *matchbalance (MatchState *ms, const char *s, static const char *matchbalance (MatchState *ms, const char *s,
const char *p) { const char *p) {
if (*p == 0 || *(p+1) == 0) if (p >= ms->p_end - 1)
luaL_error(ms->L, "unbalanced pattern"); luaL_error(ms->L, "malformed pattern "
"(missing arguments to " LUA_QL("%%b") ")");
if (*s != *p) return NULL; if (*s != *p) return NULL;
else { else {
int b = *p; int b = *p;
@ -375,6 +377,8 @@ static const char *match_capture (MatchState *ms, const char *s, int l) {
static const char *match (MatchState *ms, const char *s, const char *p) { static const char *match (MatchState *ms, const char *s, const char *p) {
init: /* using goto's to optimize tail recursion */ init: /* using goto's to optimize tail recursion */
if (p == ms->p_end) /* end of pattern? */
return s; /* match succeeded */
switch (*p) { switch (*p) {
case '(': { /* start capture */ case '(': { /* start capture */
if (*(p+1) == ')') /* position capture? */ if (*(p+1) == ')') /* position capture? */
@ -385,11 +389,8 @@ static const char *match (MatchState *ms, const char *s, const char *p) {
case ')': { /* end capture */ case ')': { /* end capture */
return end_capture(ms, s, p+1); return end_capture(ms, s, p+1);
} }
case '\0': { /* end of pattern */
return s; /* match succeeded */
}
case '$': { case '$': {
if (*(p+1) == '\0') /* is the `$' the last char in pattern? */ if ((p+1) == ms->p_end) /* is the `$' the last char in pattern? */
return (s == ms->src_end) ? s : NULL; /* check end of string */ return (s == ms->src_end) ? s : NULL; /* check end of string */
else goto dflt; else goto dflt;
} }
@ -419,12 +420,12 @@ static const char *match (MatchState *ms, const char *s, const char *p) {
if (s == NULL) return NULL; if (s == NULL) return NULL;
p+=2; goto init; /* else return match(ms, s, p+2) */ p+=2; goto init; /* else return match(ms, s, p+2) */
} }
default: break; /* go through to 'dflt' */ default: goto dflt;
} }
} }
default: dflt: { /* pattern class plus optional sufix */ default: dflt: { /* pattern class plus optional sufix */
const char *ep = classend(ms, p); /* points to what is next */ const char *ep = classend(ms, p); /* points to what is next */
int m = s<ms->src_end && singlematch(uchar(*s), p, ep); int m = s < ms->src_end && singlematch(uchar(*s), p, ep);
switch (*ep) { switch (*ep) {
case '?': { /* optional */ case '?': { /* optional */
const char *res; const char *res;
@ -504,32 +505,36 @@ static int push_captures (MatchState *ms, const char *s, const char *e) {
static int str_find_aux (lua_State *L, int find) { static int str_find_aux (lua_State *L, int find) {
size_t l1, l2; size_t ls, lp;
const char *s = luaL_checklstring(L, 1, &l1); const char *s = luaL_checklstring(L, 1, &ls);
const char *p = luaL_checklstring(L, 2, &l2); const char *p = luaL_checklstring(L, 2, &lp);
size_t init = posrelat(luaL_optinteger(L, 3, 1), l1); size_t init = posrelat(luaL_optinteger(L, 3, 1), ls);
if (init < 1) init = 1; if (init < 1) init = 1;
else if (init > l1 + 1) { /* start after string's end? */ else if (init > ls + 1) { /* start after string's end? */
lua_pushnil(L); /* cannot find anything */ lua_pushnil(L); /* cannot find anything */
return 1; return 1;
} }
if (find && (lua_toboolean(L, 4) || /* explicit request? */ if (find && (lua_toboolean(L, 4) || /* explicit request? */
strpbrk(p, SPECIALS) == NULL)) { /* or no special characters? */ strpbrk(p, SPECIALS) == NULL)) { /* or no special characters? */
/* do a plain search */ /* do a plain search */
const char *s2 = lmemfind(s + init - 1, l1 - init + 1, p, l2); const char *s2 = lmemfind(s + init - 1, ls - init + 1, p, lp);
if (s2) { if (s2) {
lua_pushinteger(L, s2 - s + 1); lua_pushinteger(L, s2 - s + 1);
lua_pushinteger(L, s2 - s + l2); lua_pushinteger(L, s2 - s + lp);
return 2; return 2;
} }
} }
else { else {
MatchState ms; MatchState ms;
int anchor = (*p == '^') ? (p++, 1) : 0;
const char *s1 = s + init - 1; const char *s1 = s + init - 1;
int anchor = (*p == '^');
if (anchor) {
p++; lp--; /* skip anchor character */
}
ms.L = L; ms.L = L;
ms.src_init = s; ms.src_init = s;
ms.src_end = s + l1; ms.src_end = s + ls;
ms.p_end = p + lp;
do { do {
const char *res; const char *res;
ms.level = 0; ms.level = 0;
@ -561,13 +566,14 @@ static int str_match (lua_State *L) {
static int gmatch_aux (lua_State *L) { static int gmatch_aux (lua_State *L) {
MatchState ms; MatchState ms;
size_t ls; size_t ls, lp;
const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls); const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls);
const char *p = lua_tostring(L, lua_upvalueindex(2)); const char *p = lua_tolstring(L, lua_upvalueindex(2), &lp);
const char *src; const char *src;
ms.L = L; ms.L = L;
ms.src_init = s; ms.src_init = s;
ms.src_end = s+ls; ms.src_end = s+ls;
ms.p_end = p + lp;
for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3)); for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3));
src <= ms.src_end; src <= ms.src_end;
src++) { src++) {
@ -659,12 +665,12 @@ static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,
static int str_gsub (lua_State *L) { static int str_gsub (lua_State *L) {
size_t srcl; size_t srcl, lp;
const char *src = luaL_checklstring(L, 1, &srcl); const char *src = luaL_checklstring(L, 1, &srcl);
const char *p = luaL_checkstring(L, 2); const char *p = luaL_checklstring(L, 2, &lp);
int tr = lua_type(L, 3); int tr = lua_type(L, 3);
size_t max_s = luaL_optinteger(L, 4, srcl+1); size_t max_s = luaL_optinteger(L, 4, srcl+1);
int anchor = (*p == '^') ? (p++, 1) : 0; int anchor = (*p == '^');
size_t n = 0; size_t n = 0;
MatchState ms; MatchState ms;
luaL_Buffer b; luaL_Buffer b;
@ -672,9 +678,13 @@ static int str_gsub (lua_State *L) {
tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3, tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,
"string/function/table expected"); "string/function/table expected");
luaL_buffinit(L, &b); luaL_buffinit(L, &b);
if (anchor) {
p++; lp--; /* skip anchor character */
}
ms.L = L; ms.L = L;
ms.src_init = src; ms.src_init = src;
ms.src_end = src+srcl; ms.src_end = src+srcl;
ms.p_end = p + lp;
while (n < max_s) { while (n < max_s) {
const char *e; const char *e;
ms.level = 0; ms.level = 0;