/* ** $Id: lstrlib.c,v 1.102 2004/04/30 20:13:38 roberto Exp roberto $ ** Standard library for string operations and pattern-matching ** See Copyright Notice in lua.h */ #include #include #include #include #include #define lstrlib_c #define LUA_LIB #include "lua.h" #include "lauxlib.h" #include "lualib.h" /* macro to `unsign' a character */ #define uchar(c) ((unsigned char)(c)) typedef lua_Integer sint32; /* a signed version for size_t */ static int str_len (lua_State *L) { size_t l; luaL_checklstring(L, 1, &l); lua_pushinteger(L, l); return 1; } static sint32 posrelat (sint32 pos, size_t len) { /* relative string position: negative means back from end */ return (pos>=0) ? pos : (sint32)len+pos+1; } static int str_sub (lua_State *L) { size_t l; const char *s = luaL_checklstring(L, 1, &l); sint32 start = posrelat(luaL_checkinteger(L, 2), l); sint32 end = posrelat(luaL_optinteger(L, 3, -1), l); if (start < 1) start = 1; if (end > (sint32)l) end = (sint32)l; if (start <= end) lua_pushlstring(L, s+start-1, end-start+1); else lua_pushliteral(L, ""); return 1; } static int str_reverse (lua_State *L) { size_t l; luaL_Buffer b; const char *s = luaL_checklstring(L, 1, &l); luaL_buffinit(L, &b); while (l--) luaL_putchar(&b, s[l]); luaL_pushresult(&b); return 1; } static int str_lower (lua_State *L) { size_t l; size_t i; luaL_Buffer b; const char *s = luaL_checklstring(L, 1, &l); luaL_buffinit(L, &b); for (i=0; i 0) luaL_addlstring(&b, s, l); luaL_pushresult(&b); return 1; } static int str_byte (lua_State *L) { size_t l; const char *s = luaL_checklstring(L, 1, &l); sint32 pos = posrelat(luaL_optinteger(L, 2, 1), l); if (pos <= 0 || (size_t)(pos) > l) /* index out of range? */ return 0; /* no answer */ lua_pushinteger(L, uchar(s[pos-1])); return 1; } static int str_char (lua_State *L) { int n = lua_gettop(L); /* number of arguments */ int i; luaL_Buffer b; luaL_buffinit(L, &b); for (i=1; i<=n; i++) { int c = luaL_checkint(L, i); luaL_argcheck(L, uchar(c) == c, i, "invalid value"); luaL_putchar(&b, uchar(c)); } luaL_pushresult(&b); return 1; } static int writer (lua_State *L, const void* b, size_t size, void* B) { (void)L; luaL_addlstring((luaL_Buffer*) B, (const char *)b, size); return 1; } static int str_dump (lua_State *L) { luaL_Buffer b; luaL_checktype(L, 1, LUA_TFUNCTION); lua_settop(L, 1); luaL_buffinit(L,&b); if (!lua_dump(L, writer, &b)) luaL_error(L, "unable to dump given function"); luaL_pushresult(&b); return 1; } /* ** {====================================================== ** PATTERN MATCHING ** ======================================================= */ #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 */ lua_State *L; int level; /* total number of captures (finished or unfinished) */ struct { const char *init; sint32 len; } capture[MAX_CAPTURES]; } MatchState; #define ESC '%' #define SPECIALS "^$*+?.([%-" static int check_capture (MatchState *ms, int l) { l -= '1'; if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED) return luaL_error(ms->L, "invalid capture index"); return l; } static int capture_to_close (MatchState *ms) { int level = ms->level; for (level--; level>=0; level--) if (ms->capture[level].len == CAP_UNFINISHED) return level; return luaL_error(ms->L, "invalid pattern capture"); } static const char *luaI_classend (MatchState *ms, const char *p) { switch (*p++) { case ESC: { if (*p == '\0') luaL_error(ms->L, "malformed pattern (ends with `%%')"); return p+1; } case '[': { if (*p == '^') p++; do { /* look for a `]' */ if (*p == '\0') luaL_error(ms->L, "malformed pattern (missing `]')"); if (*(p++) == ESC && *p != '\0') p++; /* skip escapes (e.g. `%]') */ } while (*p != ']'); return p+1; } default: { return p; } } } static int match_class (int c, int cl) { int res; switch (tolower(cl)) { case 'a' : res = isalpha(c); break; case 'c' : res = iscntrl(c); break; case 'd' : res = isdigit(c); break; case 'l' : res = islower(c); break; case 'p' : res = ispunct(c); break; case 's' : res = isspace(c); break; case 'u' : res = isupper(c); break; case 'w' : res = isalnum(c); break; case 'x' : res = isxdigit(c); break; case 'z' : res = (c == 0); break; default: return (cl == c); } return (islower(cl) ? res : !res); } static int matchbracketclass (int c, const char *p, const char *ec) { int sig = 1; if (*(p+1) == '^') { sig = 0; p++; /* skip the `^' */ } while (++p < ec) { if (*p == ESC) { p++; if (match_class(c, *p)) return sig; } else if ((*(p+1) == '-') && (p+2 < ec)) { p+=2; if (uchar(*(p-2)) <= c && c <= uchar(*p)) return sig; } else if (uchar(*p) == c) return sig; } return !sig; } static int luaI_singlematch (int c, const char *p, const char *ep) { switch (*p) { case '.': return 1; /* matches any char */ case ESC: return match_class(c, *(p+1)); case '[': return matchbracketclass(c, p, ep-1); default: return (uchar(*p) == c); } } static const char *match (MatchState *ms, const char *s, const char *p); static const char *matchbalance (MatchState *ms, const char *s, const char *p) { if (*p == 0 || *(p+1) == 0) luaL_error(ms->L, "unbalanced pattern"); if (*s != *p) return NULL; else { int b = *p; int e = *(p+1); int cont = 1; while (++s < ms->src_end) { if (*s == e) { if (--cont == 0) return s+1; } else if (*s == b) cont++; } } return NULL; /* string ends out of balance */ } static const char *max_expand (MatchState *ms, const char *s, const char *p, const char *ep) { sint32 i = 0; /* counts maximum expand for item */ while ((s+i)src_end && luaI_singlematch(uchar(*(s+i)), p, ep)) i++; /* keeps trying to match with the maximum repetitions */ while (i>=0) { const char *res = match(ms, (s+i), ep+1); if (res) return res; i--; /* else didn't match; reduce 1 repetition to try again */ } return NULL; } static const char *min_expand (MatchState *ms, const char *s, const char *p, const char *ep) { for (;;) { const char *res = match(ms, s, ep+1); if (res != NULL) return res; else if (ssrc_end && luaI_singlematch(uchar(*s), p, ep)) s++; /* try with one more repetition */ else return NULL; } } 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) luaL_error(ms->L, "too many captures"); ms->capture[level].init = s; ms->capture[level].len = what; ms->level = level+1; if ((res=match(ms, s, p)) == NULL) /* match failed? */ ms->level--; /* undo capture */ return res; } 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)) == NULL) /* match failed? */ ms->capture[l].len = CAP_UNFINISHED; /* undo capture */ return res; } static const char *match_capture (MatchState *ms, const char *s, int l) { size_t len; l = check_capture(ms, l); len = ms->capture[l].len; if ((size_t)(ms->src_end-s) >= len && memcmp(ms->capture[l].init, s, len) == 0) return s+len; else return NULL; } 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 */ 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+1); } case ESC: { switch (*(p+1)) { case 'b': { /* balanced string? */ s = matchbalance(ms, s, p+2); if (s == NULL) return NULL; p+=4; goto init; /* else return match(ms, s, p+4); */ } case 'f': { /* frontier? */ const char *ep; char previous; p += 2; if (*p != '[') luaL_error(ms->L, "missing `[' after `%%f' in pattern"); ep = luaI_classend(ms, p); /* points to what is next */ previous = (s == ms->src_init) ? '\0' : *(s-1); if (matchbracketclass(uchar(previous), p, ep-1) || !matchbracketclass(uchar(*s), p, ep-1)) return NULL; p=ep; goto init; /* else return match(ms, s, ep); */ } default: { if (isdigit(uchar(*(p+1)))) { /* capture results (%0-%9)? */ s = match_capture(ms, s, *(p+1)); if (s == NULL) return NULL; p+=2; goto init; /* else return match(ms, s, p+2) */ } goto dflt; /* case default */ } } } case '\0': { /* end of pattern */ return s; /* match succeeded */ } case '$': { if (*(p+1) == '\0') /* is the `$' the last char in pattern? */ return (s == ms->src_end) ? s : NULL; /* check end of string */ else goto dflt; } default: dflt: { /* it is a pattern item */ const char *ep = luaI_classend(ms, p); /* points to what is next */ int m = ssrc_end && luaI_singlematch(uchar(*s), p, ep); switch (*ep) { case '?': { /* optional */ const char *res; if (m && ((res=match(ms, s+1, ep+1)) != NULL)) return res; p=ep+1; goto init; /* else return match(ms, s, ep+1); */ } case '*': { /* 0 or more repetitions */ return max_expand(ms, s, p, ep); } case '+': { /* 1 or more repetitions */ return (m ? max_expand(ms, s+1, p, ep) : NULL); } case '-': { /* 0 or more repetitions (minimum) */ return min_expand(ms, s, p, ep); } default: { if (!m) return NULL; s++; p=ep; goto init; /* else return match(ms, s+1, ep); */ } } } } } static const char *lmemfind (const char *s1, size_t l1, const char *s2, size_t l2) { if (l2 == 0) return s1; /* empty strings are everywhere */ else if (l2 > l1) return NULL; /* avoids a negative `l1' */ else { const char *init; /* to search for a `*s2' inside `s1' */ l2--; /* 1st char will be checked by `memchr' */ l1 = l1-l2; /* `s2' cannot be found after that */ while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) { init++; /* 1st char is already checked */ if (memcmp(init, s2+1, l2) == 0) return init-1; else { /* correct `l1' and `s1' to try again */ l1 -= init-s1; s1 = init; } } return NULL; /* not found */ } } static void push_onecapture (MatchState *ms, int i) { int l = ms->capture[i].len; if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture"); if (l == CAP_POSITION) lua_pushinteger(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, const char *s, const char *e) { int i; luaL_checkstack(ms->L, ms->level, "too many captures"); if (ms->level == 0 && s) { /* no explicit captures? */ lua_pushlstring(ms->L, s, e-s); /* return whole match */ return 1; } else { /* return all captures */ for (i=0; ilevel; i++) push_onecapture(ms, i); return ms->level; /* number of strings pushed */ } } static int str_find (lua_State *L) { size_t l1, l2; const char *s = luaL_checklstring(L, 1, &l1); const char *p = luaL_checklstring(L, 2, &l2); sint32 init = posrelat(luaL_optinteger(L, 3, 1), l1) - 1; if (init < 0) init = 0; else if ((size_t)(init) > l1) init = (sint32)l1; if (lua_toboolean(L, 4) || /* explicit request? */ strpbrk(p, SPECIALS) == NULL) { /* or no special characters? */ /* do a plain search */ const char *s2 = lmemfind(s+init, l1-init, p, l2); if (s2) { lua_pushinteger(L, s2-s+1); lua_pushinteger(L, s2-s+l2); return 2; } } else { MatchState ms; 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; ms.level = 0; if ((res=match(&ms, s1, p)) != NULL) { lua_pushinteger(L, s1-s+1); /* start */ lua_pushinteger(L, res-s); /* end */ return push_captures(&ms, NULL, 0) + 2; } } while (s1++L; if (lua_isstring(L, 3)) { const char *news = lua_tostring(L, 3); size_t l = lua_strlen(L, 3); size_t i; for (i=0; i= 3 && (lua_isstring(L, 3) || lua_isfunction(L, 3)), 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; ms.level = 0; e = match(&ms, src, p); if (e) { n++; add_s(&ms, &b, src, e); } if (e && e>src) /* non empty match? */ src = e; /* skip it */ else if (src < ms.src_end) luaL_putchar(&b, *src++); else break; if (anchor) break; } luaL_addlstring(&b, src, ms.src_end-src); luaL_pushresult(&b); lua_pushinteger(L, n); /* number of substitutions */ return 2; } /* }====================================================== */ /* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */ #define MAX_ITEM 512 /* maximum size of each format specification (such as '%-099.99d') */ #define MAX_FORMAT 20 static void luaI_addquoted (lua_State *L, luaL_Buffer *b, int arg) { size_t l; const char *s = luaL_checklstring(L, arg, &l); luaL_putchar(b, '"'); while (l--) { switch (*s) { case '"': case '\\': case '\n': { luaL_putchar(b, '\\'); luaL_putchar(b, *s); break; } case '\0': { luaL_addlstring(b, "\\000", 4); break; } default: { luaL_putchar(b, *s); break; } } s++; } luaL_putchar(b, '"'); } static const char *scanformat (lua_State *L, const char *strfrmt, char *form, int *hasprecision) { const char *p = strfrmt; while (strchr("-+ #0", *p)) p++; /* skip flags */ if (isdigit(uchar(*p))) p++; /* skip width */ if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ if (*p == '.') { p++; *hasprecision = 1; if (isdigit(uchar(*p))) p++; /* skip precision */ if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ } if (isdigit(uchar(*p))) luaL_error(L, "invalid format (width or precision too long)"); if (p-strfrmt+2 > MAX_FORMAT) /* +2 to include `%' and the specifier */ luaL_error(L, "invalid format (too long)"); form[0] = ESC; strncpy(form+1, strfrmt, p-strfrmt+1); form[p-strfrmt+2] = 0; return p; } static int str_format (lua_State *L) { int arg = 1; size_t sfl; const char *strfrmt = luaL_checklstring(L, arg, &sfl); const char *strfrmt_end = strfrmt+sfl; luaL_Buffer b; luaL_buffinit(L, &b); while (strfrmt < strfrmt_end) { if (*strfrmt != ESC) luaL_putchar(&b, *strfrmt++); else if (*++strfrmt == ESC) luaL_putchar(&b, *strfrmt++); /* %% */ else { /* format item */ char form[MAX_FORMAT]; /* to store the format (`%...') */ char buff[MAX_ITEM]; /* to store the formatted item */ int hasprecision = 0; if (isdigit(uchar(*strfrmt)) && *(strfrmt+1) == '$') return luaL_error(L, "obsolete option (d$) to `format'"); arg++; strfrmt = scanformat(L, strfrmt, form, &hasprecision); switch (*strfrmt++) { case 'c': case 'd': case 'i': { sprintf(buff, form, luaL_checkint(L, arg)); break; } case 'o': case 'u': case 'x': case 'X': { sprintf(buff, form, (unsigned int)(luaL_checknumber(L, arg))); break; } case 'e': case 'E': case 'f': case 'g': case 'G': { sprintf(buff, form, luaL_checknumber(L, arg)); break; } case 'q': { luaI_addquoted(L, &b, arg); continue; /* skip the `addsize' at the end */ } case 's': { size_t l; const char *s = luaL_checklstring(L, arg, &l); if (!hasprecision && l >= 100) { /* no precision and string is too long to be formatted; keep original string */ lua_pushvalue(L, arg); luaL_addvalue(&b); continue; /* skip the `addsize' at the end */ } else { sprintf(buff, form, s); break; } } default: { /* also treat cases `pnLlh' */ return luaL_error(L, "invalid option to `format'"); } } luaL_addlstring(&b, buff, strlen(buff)); } } luaL_pushresult(&b); return 1; } static const luaL_reg strlib[] = { {"len", str_len}, {"sub", str_sub}, {"reverse", str_reverse}, {"lower", str_lower}, {"upper", str_upper}, {"char", str_char}, {"rep", str_rep}, {"byte", str_byte}, {"format", str_format}, {"dump", str_dump}, {"find", str_find}, {"gfind", gfind}, {"gsub", str_gsub}, {NULL, NULL} }; /* ** Open string library */ LUALIB_API int luaopen_string (lua_State *L) { luaL_openlib(L, LUA_STRLIBNAME, strlib, 0); return 1; }