/* ** Read a number: first reads a valid prefix of a numeral into a buffer. ** Then it calls 'lua_stringtonumber' to check whether the format is ** correct and to convert it to a Lua number */ static int read_number (lua_State *L, FILE *f) { RN rn; int count = 0; int hex = 0; char decp[2]; rn.f = f; rn.n = 0; decp[0] = lua_getlocaledecpoint(); /* get decimal point from locale */ decp[1] = '.'; /* always accept a dot */ l_lockfile(rn.f); do { rn.c = l_getc(rn.f); } while (isspace(rn.c)); /* skip spaces */ test2(&rn, "-+"); /* optional signal */ if (test2(&rn, "00")) { if (test2(&rn, "xX")) hex = 1; /* numeral is hexadecimal */ else count = 1; /* count initial '0' as a valid digit */ } count += readdigits(&rn, hex); /* integral part */ if (test2(&rn, decp)) /* decimal point? */ count += readdigits(&rn, hex); /* fractional part */ if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) { /* exponent mark? */ test2(&rn, "-+"); /* exponent signal */ readdigits(&rn, 0); /* exponent digits */ } ungetc(rn.c, rn.f); /* unread look-ahead char */ l_unlockfile(rn.f); rn.buff[rn.n] = '\0'; /* finish string */ if (lua_stringtonumber(L, rn.buff)) /* is this a valid number? */ return 1; /* ok */ else { /* invalid format */ lua_pushnil(L); /* "result" to be removed */ return 0; /* read fails */ } }
static int num2straux (char *buff, int sz, lua_Number x) { /* if 'inf' or 'NaN', format it like '%g' */ if (x != x || x == (lua_Number)HUGE_VAL || x == -(lua_Number)HUGE_VAL) return l_sprintf(buff, sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)x); else if (x == 0) { /* can be -0... */ /* create "0" or "-0" followed by exponent */ return l_sprintf(buff, sz, LUA_NUMBER_FMT "x0p+0", (LUAI_UACNUMBER)x); } else { int e; lua_Number m = l_mathop(frexp)(x, &e); /* 'x' fraction and exponent */ int n = 0; /* character count */ if (m < 0) { /* is number negative? */ buff[n++] = '-'; /* add sign */ m = -m; /* make it positive */ } buff[n++] = '0'; buff[n++] = 'x'; /* add "0x" */ m = adddigit(buff, n++, m * (1 << L_NBFD)); /* add first digit */ e -= L_NBFD; /* this digit goes before the radix point */ if (m > 0) { /* more digits? */ buff[n++] = lua_getlocaledecpoint(); /* add radix point */ do { /* add as many digits as needed */ m = adddigit(buff, n++, m * 16); } while (m > 0); } n += l_sprintf(buff + n, sz - n, "p%+d", e); /* add exponent */ lua_assert(n < sz); return n; } }
static int num2straux (char *buff, lua_Number x) { if (x != x || x == HUGE_VAL || x == -HUGE_VAL) /* inf or NaN? */ return sprintf(buff, LUA_NUMBER_FMT, x); /* equal to '%g' */ else if (x == 0) { /* can be -0... */ sprintf(buff, LUA_NUMBER_FMT, x); strcat(buff, "x0p+0"); /* reuses '0/-0' from 'sprintf'... */ return (int)strlen(buff); /* Custom change: fixed 64-bit compilation warning */ } else { int e; lua_Number m = l_mathop(frexp)(x, &e); /* 'x' fraction and exponent */ int n = 0; /* character count */ if (m < 0) { /* is number negative? */ buff[n++] = '-'; /* add signal */ m = -m; /* make it positive */ } buff[n++] = '0'; buff[n++] = 'x'; /* add "0x" */ m = adddigit(buff, n++, m * (1 << L_NBFD)); /* add first digit */ e -= L_NBFD; /* this digit goes before the radix point */ if (m > 0) { /* more digits? */ buff[n++] = lua_getlocaledecpoint(); /* add radix point */ do { /* add as many digits as needed */ m = adddigit(buff, n++, m * 16); } while (m > 0); } n += sprintf(buff + n, "p%+d", e); /* add exponent */ return n; } }
/* ** Ensures the 'buff' string uses a dot as the radix character. */ static void checkdp (char *buff, int nb) { if (memchr(buff, '.', nb) == NULL) { /* no dot? */ char point = lua_getlocaledecpoint(); /* try locale point */ char *ppoint = (char*)memchr(buff, point, nb); if (ppoint) *ppoint = '.'; /* change it to a dot */ } }
/* ** in case of format error, try to change decimal point separator to ** the one defined in the current locale and check again */ static void trydecpoint (LexState *ls, TValue *o) { char old = ls->decpoint; ls->decpoint = lua_getlocaledecpoint(); buffreplace(ls, old, ls->decpoint); /* try new decimal separator */ if (!buff2num(ls->buff, o)) { /* format error with correct decimal point: no more options */ buffreplace(ls, ls->decpoint, '.'); /* undo change (for error message) */ lexerror(ls, "malformed number", TK_FLT); } }
/* ** convert an hexadecimal numeric string to a number, following ** C99 specification for 'strtod' */ static lua_Number lua_strx2number (const char *s, char **endptr) { int dot = lua_getlocaledecpoint(); lua_Number r = 0.0; /* result (accumulator) */ int sigdig = 0; /* number of significant digits */ int nosigdig = 0; /* number of non-significant digits */ int e = 0; /* exponent correction */ int neg; /* 1 if number is negative */ int hasdot = 0; /* true after seen a dot */ *endptr = cast(char *, s); /* nothing is valid yet */ while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ neg = isneg(&s); /* check signal */ if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */ return 0.0; /* invalid format (no '0x') */ for (s += 2; ; s++) { /* skip '0x' and read numeral */ if (*s == dot) { if (hasdot) break; /* second dot? stop loop */ else hasdot = 1; } else if (lisxdigit(cast_uchar(*s))) { if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */ nosigdig++; else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */ r = (r * cast_num(16.0)) + luaO_hexavalue(*s); else e++; /* too many digits; ignore, but still count for exponent */ if (hasdot) e--; /* decimal digit? correct exponent */ } else break; /* neither a dot nor a digit */ } if (nosigdig + sigdig == 0) /* no digits? */ return 0.0; /* invalid format */ *endptr = cast(char *, s); /* valid up to here */ e *= 4; /* each digit multiplies/divides value by 2^4 */ if (*s == 'p' || *s == 'P') { /* exponent part? */ int exp1 = 0; /* exponent value */ int neg1; /* exponent signal */ s++; /* skip 'p' */ neg1 = isneg(&s); /* signal */ if (!lisdigit(cast_uchar(*s))) return 0.0; /* invalid; must have at least one digit */ while (lisdigit(cast_uchar(*s))) /* read exponent */ exp1 = exp1 * 10 + *(s++) - '0'; if (neg1) exp1 = -exp1; e += exp1; *endptr = cast(char *, s); /* valid up to here */ }
/* ** Serialize a floating-point number in such a way that it can be ** scanned back by Lua. Use hexadecimal format for "common" numbers ** (to preserve precision); inf, -inf, and NaN are handled separately. ** (NaN cannot be expressed as a numeral, so we write '(0/0)' for it.) */ static int quotefloat (lua_State *L, char *buff, lua_Number n) { const char *s; /* for the fixed representations */ if (n == (lua_Number)HUGE_VAL) /* inf? */ s = "1e9999"; else if (n == -(lua_Number)HUGE_VAL) /* -inf? */ s = "-1e9999"; else if (n != n) /* NaN? */ s = "(0/0)"; else { /* format number as hexadecimal */ int nb = lua_number2strx(L, buff, MAX_ITEM, "%" LUA_NUMBER_FRMLEN "a", n); /* ensures that 'buff' string uses a dot as the radix character */ if (memchr(buff, '.', nb) == NULL) { /* no dot? */ char point = lua_getlocaledecpoint(); /* try locale point */ char *ppoint = (char *)memchr(buff, point, nb); if (ppoint) *ppoint = '.'; /* change it to a dot */ } return nb; } /* for the fixed representations */ return l_sprintf(buff, MAX_ITEM, "%s", s); }