| /* |
| ** $Id: lstrlib.c,v 1.52 2000/09/11 17:38:42 roberto Exp roberto $ |
| ** Standard library for string operations and pattern-matching |
| ** See Copyright Notice in lua.h |
| */ |
| |
| |
| #include <ctype.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "lua.h" |
| |
| #include "lauxlib.h" |
| #include "lualib.h" |
| |
| |
| |
| static int str_len (lua_State *L) { |
| size_t l; |
| luaL_check_lstr(L, 1, &l); |
| lua_pushnumber(L, l); |
| return 1; |
| } |
| |
| |
| static long posrelat (long pos, size_t len) { |
| /* relative string position: negative means back from end */ |
| return (pos>=0) ? pos : (long)len+pos+1; |
| } |
| |
| |
| static int str_sub (lua_State *L) { |
| size_t l; |
| const char *s = luaL_check_lstr(L, 1, &l); |
| long start = posrelat(luaL_check_long(L, 2), l); |
| long end = posrelat(luaL_opt_long(L, 3, -1), l); |
| if (start < 1) start = 1; |
| if (end > (long)l) end = l; |
| if (start <= end) |
| lua_pushlstring(L, s+start-1, end-start+1); |
| else lua_pushstring(L, ""); |
| return 1; |
| } |
| |
| |
| static int str_lower (lua_State *L) { |
| size_t l; |
| size_t i; |
| luaL_Buffer b; |
| const char *s = luaL_check_lstr(L, 1, &l); |
| luaL_buffinit(L, &b); |
| for (i=0; i<l; i++) |
| luaL_putchar(&b, tolower((unsigned char)(s[i]))); |
| luaL_pushresult(&b); |
| return 1; |
| } |
| |
| |
| static int str_upper (lua_State *L) { |
| size_t l; |
| size_t i; |
| luaL_Buffer b; |
| const char *s = luaL_check_lstr(L, 1, &l); |
| luaL_buffinit(L, &b); |
| for (i=0; i<l; i++) |
| luaL_putchar(&b, toupper((unsigned char)(s[i]))); |
| luaL_pushresult(&b); |
| return 1; |
| } |
| |
| static int str_rep (lua_State *L) { |
| size_t l; |
| luaL_Buffer b; |
| const char *s = luaL_check_lstr(L, 1, &l); |
| int n = luaL_check_int(L, 2); |
| luaL_buffinit(L, &b); |
| while (n-- > 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_check_lstr(L, 1, &l); |
| long pos = posrelat(luaL_opt_long(L, 2, 1), l); |
| luaL_arg_check(L, 0<pos && (size_t)pos<=l, 2, "out of range"); |
| lua_pushnumber(L, (unsigned char)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_check_int(L, i); |
| luaL_arg_check(L, (unsigned char)c == c, i, "invalid value"); |
| luaL_putchar(&b, (unsigned char)c); |
| } |
| luaL_pushresult(&b); |
| return 1; |
| } |
| |
| |
| |
| /* |
| ** {====================================================== |
| ** PATTERN MATCHING |
| ** ======================================================= |
| */ |
| |
| #ifndef MAX_CAPTURES |
| #define MAX_CAPTURES 32 /* arbitrary limit */ |
| #endif |
| |
| |
| struct Capture { |
| const char *src_end; /* end ('\0') of source string */ |
| int level; /* total number of captures (finished or unfinished) */ |
| struct { |
| const char *init; |
| long len; /* -1 signals unfinished capture */ |
| } capture[MAX_CAPTURES]; |
| }; |
| |
| |
| #define ESC '%' |
| #define SPECIALS "^$*+?.([%-" |
| |
| |
| static int check_capture (lua_State *L, int l, struct Capture *cap) { |
| l -= '1'; |
| if (!(0 <= l && l < cap->level && cap->capture[l].len != -1)) |
| lua_error(L, "invalid capture index"); |
| return l; |
| } |
| |
| |
| static int capture_to_close (lua_State *L, struct Capture *cap) { |
| int level = cap->level; |
| for (level--; level>=0; level--) |
| if (cap->capture[level].len == -1) return level; |
| lua_error(L, "invalid pattern capture"); |
| return 0; /* to avoid warnings */ |
| } |
| |
| |
| const char *luaI_classend (lua_State *L, const char *p) { |
| switch (*p++) { |
| case ESC: |
| if (*p == '\0') lua_error(L, "malformed pattern (ends with `%')"); |
| return p+1; |
| case '[': |
| if (*p == '^') p++; |
| do { /* look for a ']' */ |
| if (*p == '\0') lua_error(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 *endclass) { |
| int sig = 1; |
| if (*(p+1) == '^') { |
| sig = 0; |
| p++; /* skip the '^' */ |
| } |
| while (++p < endclass) { |
| if (*p == ESC) { |
| p++; |
| if (match_class(c, (unsigned char)*p)) |
| return sig; |
| } |
| else if ((*(p+1) == '-') && (p+2 < endclass)) { |
| p+=2; |
| if ((int)(unsigned char)*(p-2) <= c && c <= (int)(unsigned char)*p) |
| return sig; |
| } |
| else if ((int)(unsigned char)*p == c) return sig; |
| } |
| return !sig; |
| } |
| |
| |
| |
| int luaI_singlematch (int c, const char *p, const char *ep) { |
| switch (*p) { |
| case '.': /* matches any char */ |
| return 1; |
| case ESC: |
| return match_class(c, (unsigned char)*(p+1)); |
| case '[': |
| return matchbracketclass(c, p, ep-1); |
| default: |
| return ((unsigned char)*p == c); |
| } |
| } |
| |
| |
| static const char *match (lua_State *L, const char *s, const char *p, |
| struct Capture *cap); |
| |
| |
| static const char *matchbalance (lua_State *L, const char *s, const char *p, |
| struct Capture *cap) { |
| if (*p == 0 || *(p+1) == 0) |
| lua_error(L, "unbalanced pattern"); |
| if (*s != *p) return NULL; |
| else { |
| int b = *p; |
| int e = *(p+1); |
| int cont = 1; |
| while (++s < cap->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 (lua_State *L, const char *s, const char *p, |
| const char *ep, struct Capture *cap) { |
| long i = 0; /* counts maximum expand for item */ |
| while ((s+i)<cap->src_end && luaI_singlematch((unsigned char)*(s+i), p, ep)) |
| i++; |
| /* keeps trying to match with the maximum repetitions */ |
| while (i>=0) { |
| const char *res = match(L, (s+i), ep+1, cap); |
| if (res) return res; |
| i--; /* else didn't match; reduce 1 repetition to try again */ |
| } |
| return NULL; |
| } |
| |
| |
| static const char *min_expand (lua_State *L, const char *s, const char *p, |
| const char *ep, struct Capture *cap) { |
| for (;;) { |
| const char *res = match(L, s, ep+1, cap); |
| if (res != NULL) |
| return res; |
| else if (s<cap->src_end && luaI_singlematch((unsigned char)*s, p, ep)) |
| s++; /* try with one more repetition */ |
| else return NULL; |
| } |
| } |
| |
| |
| static const char *start_capture (lua_State *L, const char *s, const char *p, |
| struct Capture *cap) { |
| const char *res; |
| int level = cap->level; |
| if (level >= MAX_CAPTURES) lua_error(L, "too many captures"); |
| cap->capture[level].init = s; |
| cap->capture[level].len = -1; |
| cap->level = level+1; |
| if ((res=match(L, s, p+1, cap)) == NULL) /* match failed? */ |
| cap->level--; /* undo capture */ |
| return res; |
| } |
| |
| |
| static const char *end_capture (lua_State *L, const char *s, const char *p, |
| struct Capture *cap) { |
| int l = capture_to_close(L, cap); |
| const char *res; |
| cap->capture[l].len = s - cap->capture[l].init; /* close capture */ |
| if ((res = match(L, s, p+1, cap)) == NULL) /* match failed? */ |
| cap->capture[l].len = -1; /* undo capture */ |
| return res; |
| } |
| |
| |
| static const char *match_capture (lua_State *L, const char *s, int level, |
| struct Capture *cap) { |
| int l = check_capture(L, level, cap); |
| size_t len = cap->capture[l].len; |
| if ((size_t)(cap->src_end-s) >= len && |
| memcmp(cap->capture[l].init, s, len) == 0) |
| return s+len; |
| else return NULL; |
| } |
| |
| |
| static const char *match (lua_State *L, const char *s, const char *p, |
| struct Capture *cap) { |
| init: /* using goto's to optimize tail recursion */ |
| switch (*p) { |
| case '(': /* start capture */ |
| return start_capture(L, s, p, cap); |
| case ')': /* end capture */ |
| return end_capture(L, s, p, cap); |
| case ESC: /* may be %[0-9] or %b */ |
| if (isdigit((unsigned char)(*(p+1)))) { /* capture? */ |
| s = match_capture(L, s, *(p+1), cap); |
| if (s == NULL) return NULL; |
| p+=2; goto init; /* else return match(L, s, p+2, cap) */ |
| } |
| else if (*(p+1) == 'b') { /* balanced string? */ |
| s = matchbalance(L, s, p+2, cap); |
| if (s == NULL) return NULL; |
| p+=4; goto init; /* else return match(L, s, p+4, cap); */ |
| } |
| else 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 == cap->src_end) ? s : NULL; /* check end of string */ |
| else goto dflt; |
| default: dflt: { /* it is a pattern item */ |
| const char *ep = luaI_classend(L, p); /* points to what is next */ |
| int m = s<cap->src_end && luaI_singlematch((unsigned char)*s, p, ep); |
| switch (*ep) { |
| case '?': { /* optional */ |
| const char *res; |
| if (m && ((res=match(L, s+1, ep+1, cap)) != NULL)) |
| return res; |
| p=ep+1; goto init; /* else return match(L, s, ep+1, cap); */ |
| } |
| case '*': /* 0 or more repetitions */ |
| return max_expand(L, s, p, ep, cap); |
| case '+': /* 1 or more repetitions */ |
| return (m ? max_expand(L, s+1, p, ep, cap) : NULL); |
| case '-': /* 0 or more repetitions (minimum) */ |
| return min_expand(L, s, p, ep, cap); |
| default: |
| if (!m) return NULL; |
| s++; p=ep; goto init; /* else return match(L, s+1, ep, cap); */ |
| } |
| } |
| } |
| } |
| |
| |
| |
| 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 int push_captures (lua_State *L, struct Capture *cap) { |
| int i; |
| luaL_checkstack(L, cap->level, "too many captures"); |
| for (i=0; i<cap->level; i++) { |
| int l = cap->capture[i].len; |
| if (l == -1) lua_error(L, "unfinished capture"); |
| lua_pushlstring(L, cap->capture[i].init, l); |
| } |
| return cap->level; /* number of strings pushed */ |
| } |
| |
| |
| static int str_find (lua_State *L) { |
| size_t l1, l2; |
| const char *s = luaL_check_lstr(L, 1, &l1); |
| const char *p = luaL_check_lstr(L, 2, &l2); |
| long init = posrelat(luaL_opt_long(L, 3, 1), l1) - 1; |
| struct Capture cap; |
| luaL_arg_check(L, 0 <= init && (size_t)init <= l1, 3, "out of range"); |
| if (lua_gettop(L) > 3 || /* extra argument? */ |
| strpbrk(p, SPECIALS) == NULL) { /* or no special characters? */ |
| const char *s2 = lmemfind(s+init, l1-init, p, l2); |
| if (s2) { |
| lua_pushnumber(L, s2-s+1); |
| lua_pushnumber(L, s2-s+l2); |
| return 2; |
| } |
| } |
| else { |
| int anchor = (*p == '^') ? (p++, 1) : 0; |
| const char *s1=s+init; |
| cap.src_end = s+l1; |
| do { |
| const char *res; |
| cap.level = 0; |
| if ((res=match(L, s1, p, &cap)) != NULL) { |
| lua_pushnumber(L, s1-s+1); /* start */ |
| lua_pushnumber(L, res-s); /* end */ |
| return push_captures(L, &cap) + 2; |
| } |
| } while (s1++<cap.src_end && !anchor); |
| } |
| lua_pushnil(L); /* not found */ |
| return 1; |
| } |
| |
| |
| static void add_s (lua_State *L, luaL_Buffer *b, struct Capture *cap) { |
| 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<l; i++) { |
| if (news[i] != ESC) |
| luaL_putchar(b, news[i]); |
| else { |
| i++; /* skip ESC */ |
| if (!isdigit((unsigned char)news[i])) |
| luaL_putchar(b, news[i]); |
| else { |
| int level = check_capture(L, news[i], cap); |
| luaL_addlstring(b, cap->capture[level].init, cap->capture[level].len); |
| } |
| } |
| } |
| } |
| else { /* is a function */ |
| int n; |
| lua_pushvalue(L, 3); |
| n = push_captures(L, cap); |
| lua_rawcall(L, n, 1); |
| if (lua_isstring(L, -1)) |
| luaL_addvalue(b); /* add return to accumulated result */ |
| else |
| lua_pop(L, 1); /* function result is not a string: pop it */ |
| } |
| } |
| |
| |
| static int str_gsub (lua_State *L) { |
| size_t srcl; |
| const char *src = luaL_check_lstr(L, 1, &srcl); |
| const char *p = luaL_check_string(L, 2); |
| int max_s = luaL_opt_int(L, 4, srcl+1); |
| int anchor = (*p == '^') ? (p++, 1) : 0; |
| int n = 0; |
| struct Capture cap; |
| luaL_Buffer b; |
| luaL_arg_check(L, |
| lua_gettop(L) >= 3 && (lua_isstring(L, 3) || lua_isfunction(L, 3)), |
| 3, "string or function expected"); |
| luaL_buffinit(L, &b); |
| cap.src_end = src+srcl; |
| while (n < max_s) { |
| const char *e; |
| cap.level = 0; |
| e = match(L, src, p, &cap); |
| if (e) { |
| n++; |
| add_s(L, &b, &cap); |
| } |
| if (e && e>src) /* non empty match? */ |
| src = e; /* skip it */ |
| else if (src < cap.src_end) |
| luaL_putchar(&b, *src++); |
| else break; |
| if (anchor) break; |
| } |
| luaL_addlstring(&b, src, cap.src_end-src); |
| luaL_pushresult(&b); |
| lua_pushnumber(L, n); /* number of substitutions */ |
| return 2; |
| } |
| |
| /* }====================================================== */ |
| |
| |
| static void luaI_addquoted (lua_State *L, luaL_Buffer *b, int arg) { |
| size_t l; |
| const char *s = luaL_check_lstr(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); |
| } |
| s++; |
| } |
| luaL_putchar(b, '"'); |
| } |
| |
| /* maximum size of each formated 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 int str_format (lua_State *L) { |
| int arg = 1; |
| const char *strfrmt = luaL_check_string(L, arg); |
| luaL_Buffer b; |
| luaL_buffinit(L, &b); |
| while (*strfrmt) { |
| if (*strfrmt != '%') |
| luaL_putchar(&b, *strfrmt++); |
| else if (*++strfrmt == '%') |
| luaL_putchar(&b, *strfrmt++); /* %% */ |
| else { /* format item */ |
| struct Capture cap; |
| char form[MAX_FORMAT]; /* to store the format ('%...') */ |
| char buff[MAX_ITEM]; /* to store the formatted item */ |
| const char *initf = strfrmt; |
| form[0] = '%'; |
| if (isdigit((unsigned char)*initf) && *(initf+1) == '$') { |
| arg = *initf - '0'; |
| initf += 2; /* skip the 'n$' */ |
| } |
| arg++; |
| cap.src_end = strfrmt+strlen(strfrmt)+1; |
| cap.level = 0; |
| strfrmt = match(L, initf, "[-+ #0]*(%d*)%.?(%d*)", &cap); |
| if (cap.capture[0].len > 2 || cap.capture[1].len > 2 || /* < 100? */ |
| strfrmt-initf > MAX_FORMAT-2) |
| lua_error(L, "invalid format (width or precision too long)"); |
| strncpy(form+1, initf, strfrmt-initf+1); /* +1 to include conversion */ |
| form[strfrmt-initf+2] = 0; |
| switch (*strfrmt++) { |
| case 'c': case 'd': case 'i': |
| sprintf(buff, form, luaL_check_int(L, arg)); |
| break; |
| case 'o': case 'u': case 'x': case 'X': |
| sprintf(buff, form, (unsigned int)luaL_check_number(L, arg)); |
| break; |
| case 'e': case 'E': case 'f': case 'g': case 'G': |
| sprintf(buff, form, luaL_check_number(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_check_lstr(L, arg, &l); |
| if (cap.capture[1].len == 0 && 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' */ |
| lua_error(L, "invalid option in `format'"); |
| } |
| luaL_addlstring(&b, buff, strlen(buff)); |
| } |
| } |
| luaL_pushresult(&b); |
| return 1; |
| } |
| |
| |
| static const struct luaL_reg strlib[] = { |
| {"strlen", str_len}, |
| {"strsub", str_sub}, |
| {"strlower", str_lower}, |
| {"strupper", str_upper}, |
| {"strchar", str_char}, |
| {"strrep", str_rep}, |
| {"ascii", str_byte}, /* for compatibility with 3.0 and earlier */ |
| {"strbyte", str_byte}, |
| {"format", str_format}, |
| {"strfind", str_find}, |
| {"gsub", str_gsub} |
| }; |
| |
| |
| /* |
| ** Open string library |
| */ |
| void lua_strlibopen (lua_State *L) { |
| luaL_openl(L, strlib); |
| } |