mirror of
https://github.com/nothings/stb
synced 2024-12-15 12:22:55 +03:00
stb_c_lexer.h: C99 hex float literals
* Add support for C99 hex float literals * + is acceptable in a floating-point exponent * log(n) implementation of pow for stb__clex_parse_float * Add hex int and float test cases
This commit is contained in:
Alan Hickman
fahickman
parent
c6b6239357
commit
49d3871d86
162
stb_c_lexer.h
162
stb_c_lexer.h
@ -45,7 +45,8 @@
|
||||
#define STB_C_LEX_C_DECIMAL_INTS Y // "0|[1-9][0-9]*" CLEX_intlit
|
||||
#define STB_C_LEX_C_HEX_INTS Y // "0x[0-9a-fA-F]+" CLEX_intlit
|
||||
#define STB_C_LEX_C_OCTAL_INTS Y // "[0-7]+" CLEX_intlit
|
||||
#define STB_C_LEX_C_DECIMAL_FLOATS Y // "[0-9]*(.[0-9]*([eE]-?[0-9]+)?) CLEX_floatlit
|
||||
#define STB_C_LEX_C_DECIMAL_FLOATS Y // "[0-9]*(.[0-9]*([eE][-+]?[0-9]+)?) CLEX_floatlit
|
||||
#define STB_C_LEX_C99_HEX_FLOATS N // "0x{hex}+(.{hex}*)?[pP][-+]?{hex}+ CLEX_floatlit
|
||||
#define STB_C_LEX_C_IDENTIFIERS Y // "[_a-zA-Z][_a-zA-Z0-9]*" CLEX_id
|
||||
#define STB_C_LEX_C_DQ_STRINGS Y // double-quote-delimited strings with escapes CLEX_dqstring
|
||||
#define STB_C_LEX_C_SQ_STRINGS N // single-quote-delimited strings with escapes CLEX_ssstring
|
||||
@ -171,11 +172,6 @@ extern void stb_c_lexer_get_location(const stb_lexer *lexer, const char *where,
|
||||
#define Y(x) 1
|
||||
#define N(x) 0
|
||||
|
||||
#if STB_C_LEX_USE_STDLIB(x)
|
||||
#define STB__CLEX_use_stdlib
|
||||
#include <stdlib.h>
|
||||
#endif
|
||||
|
||||
#if STB_C_LEX_INTEGERS_AS_DOUBLES(x)
|
||||
typedef double stb__clex_int;
|
||||
#define intfield real_number
|
||||
@ -200,6 +196,10 @@ typedef long stb__clex_int;
|
||||
#define STB__clex_define_shifts
|
||||
#endif
|
||||
|
||||
#if STB_C_LEX_C99_HEX_FLOATS(x)
|
||||
#define STB__clex_hex_floats
|
||||
#endif
|
||||
|
||||
#if STB_C_LEX_C_HEX_INTS(x)
|
||||
#define STB__clex_hex_ints
|
||||
#endif
|
||||
@ -220,6 +220,11 @@ typedef long stb__clex_int;
|
||||
#define STB__clex_discard_preprocessor
|
||||
#endif
|
||||
|
||||
#if STB_C_LEX_USE_STDLIB(x) && (!defined(STB__clex_hex_floats) || __STDC_VERSION__ >= 199901L)
|
||||
#define STB__CLEX_use_stdlib
|
||||
#include <stdlib.h>
|
||||
#endif
|
||||
|
||||
// Now pick a definition of Y/N that's conducive to
|
||||
// defining the enum of token names.
|
||||
#if STB_C_LEX_DEFINE_ALL_TOKEN_NAMES(x) || defined(STB_C_LEXER_SELF_TEST)
|
||||
@ -364,34 +369,95 @@ static int stb__clex_parse_suffixes(stb_lexer *lexer, long tokenid, char *start,
|
||||
}
|
||||
|
||||
#ifndef STB__CLEX_use_stdlib
|
||||
static double stb__clex_pow(double base, unsigned int exponent)
|
||||
{
|
||||
double value=1;
|
||||
for ( ; exponent; exponent >>= 1) {
|
||||
if (exponent & 1)
|
||||
value *= base;
|
||||
base *= base;
|
||||
}
|
||||
return value;
|
||||
}
|
||||
|
||||
static double stb__clex_parse_float(char *p, char **q)
|
||||
{
|
||||
char *s = p;
|
||||
double value=0;
|
||||
while (*p >= '0' && *p <= '9')
|
||||
value = value*10 + (*p++ - '0');
|
||||
if (*p == '.') {
|
||||
double powten=1, addend = 0;
|
||||
++p;
|
||||
while (*p >= '0' && *p <= '9') {
|
||||
addend = addend*10 + (*p++ - '0');
|
||||
powten *= 10;
|
||||
}
|
||||
value += addend / powten;
|
||||
}
|
||||
if (*p == 'e' || *p == 'E') {
|
||||
int sign = p[1] == '-';
|
||||
int base=10;
|
||||
int exponent=0;
|
||||
double pow10=1;
|
||||
p += 1+sign;
|
||||
|
||||
#ifdef STB__clex_hex_floats
|
||||
if (*p == '0') {
|
||||
if (p[1] == 'x' || p[1] == 'X') {
|
||||
base=16;
|
||||
p += 2;
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
for (;;) {
|
||||
if (*p >= '0' && *p <= '9')
|
||||
value = value*base + (*p++ - '0');
|
||||
#ifdef STB__clex_hex_floats
|
||||
else if (base == 16 && *p >= 'a' && *p <= 'f')
|
||||
value = value*base + 10 + (*p++ - 'a');
|
||||
else if (base == 16 && *p >= 'A' && *p <= 'F')
|
||||
value = value*base + 10 + (*p++ - 'A');
|
||||
#endif
|
||||
else
|
||||
break;
|
||||
}
|
||||
|
||||
if (*p == '.') {
|
||||
double pow, addend = 0;
|
||||
++p;
|
||||
for (pow=1; ; pow*=base) {
|
||||
if (*p >= '0' && *p <= '9')
|
||||
addend = addend*base + (*p++ - '0');
|
||||
#ifdef STB__clex_hex_floats
|
||||
else if (base == 16 && *p >= 'a' && *p <= 'f')
|
||||
addend = addend*base + 10 + (*p++ - 'a');
|
||||
else if (base == 16 && *p >= 'A' && *p <= 'F')
|
||||
addend = addend*base + 10 + (*p++ - 'A');
|
||||
#endif
|
||||
else
|
||||
break;
|
||||
}
|
||||
value += addend / pow;
|
||||
}
|
||||
#ifdef STB__clex_hex_floats
|
||||
if (base == 16) {
|
||||
// exponent required for hex float literal
|
||||
if (*p != 'p' && *p != 'P') {
|
||||
*q = s;
|
||||
return 0;
|
||||
}
|
||||
exponent = 1;
|
||||
} else
|
||||
#endif
|
||||
exponent = (*p == 'e' || *p == 'E');
|
||||
|
||||
if (exponent) {
|
||||
int sign = p[1] == '-';
|
||||
unsigned int exponent=0;
|
||||
double power=1;
|
||||
++p;
|
||||
if (*p == '-' || *p == '+')
|
||||
++p;
|
||||
while (*p >= '0' && *p <= '9')
|
||||
exponent = exponent*10 + (*p++ - '0');
|
||||
// can't use pow() from stdlib, so do it slow way
|
||||
while (exponent-- > 0)
|
||||
pow10 *= 10;
|
||||
if (sign)
|
||||
value /= pow10;
|
||||
|
||||
#ifdef STB__clex_hex_floats
|
||||
if (base == 16)
|
||||
power = stb__clex_pow(2, exponent);
|
||||
else
|
||||
value *= pow10;
|
||||
#endif
|
||||
power = stb__clex_pow(10, exponent);
|
||||
if (sign)
|
||||
value /= power;
|
||||
else
|
||||
value *= power;
|
||||
}
|
||||
*q = p;
|
||||
return value;
|
||||
@ -630,15 +696,37 @@ int stb_c_lexer_get_token(stb_lexer *lexer)
|
||||
goto single_char;
|
||||
|
||||
case '0':
|
||||
#ifdef STB__clex_hex_ints
|
||||
#if defined(STB__clex_hex_ints) || defined(STB__clex_hex_floats)
|
||||
if (p+1 != lexer->eof) {
|
||||
if (p[1] == 'x' || p[1] == 'X') {
|
||||
char *q = p+2;
|
||||
char *q;
|
||||
|
||||
#ifdef STB__clex_hex_floats
|
||||
for (q=p+2;
|
||||
q != lexer->eof && ((*q >= '0' && *q <= '9') || (*q >= 'a' && *q <= 'f') || (*q >= 'A' && *q <= 'F'));
|
||||
++q);
|
||||
if (q != lexer->eof) {
|
||||
if (*q == '.' STB_C_LEX_FLOAT_NO_DECIMAL(|| *q == 'p' || *q == 'P')) {
|
||||
#ifdef STB__CLEX_use_stdlib
|
||||
lexer->real_number = strtod((char *) p, (char**) &q);
|
||||
#else
|
||||
lexer->real_number = stb__clex_parse_float(p, &q);
|
||||
#endif
|
||||
|
||||
if (p == q)
|
||||
return stb__clex_token(lexer, CLEX_parse_error, p,q);
|
||||
return stb__clex_parse_suffixes(lexer, CLEX_floatlit, p,q, STB_C_LEX_FLOAT_SUFFIXES);
|
||||
|
||||
}
|
||||
}
|
||||
#endif // STB__CLEX_hex_floats
|
||||
|
||||
#ifdef STB__clex_hex_ints
|
||||
#ifdef STB__CLEX_use_stdlib
|
||||
lexer->int_number = strtol((char *) p, (char **) &q, 16);
|
||||
#else
|
||||
stb__clex_int n=0;
|
||||
while (q != lexer->eof) {
|
||||
for (q=p+2; q != lexer->eof; ++q) {
|
||||
if (*q >= '0' && *q <= '9')
|
||||
n = n*16 + (*q - '0');
|
||||
else if (*q >= 'a' && *q <= 'f')
|
||||
@ -647,16 +735,16 @@ int stb_c_lexer_get_token(stb_lexer *lexer)
|
||||
n = n*16 + (*q - 'A') + 10;
|
||||
else
|
||||
break;
|
||||
++q;
|
||||
}
|
||||
lexer->int_number = n;
|
||||
#endif
|
||||
if (q == p+2)
|
||||
return stb__clex_token(lexer, CLEX_parse_error, p-2,p-1);
|
||||
return stb__clex_parse_suffixes(lexer, CLEX_intlit, p,q, STB_C_LEX_HEX_SUFFIXES);
|
||||
#endif
|
||||
}
|
||||
}
|
||||
#endif // STB__clex_hex_ints
|
||||
#endif // defined(STB__clex_hex_ints) || defined(STB__clex_hex_floats)
|
||||
// can't test for octal because we might parse '0.0' as float or as '0' '.' '0',
|
||||
// so have to do float first
|
||||
|
||||
@ -788,6 +876,14 @@ multiline comments */
|
||||
|
||||
void dummy(void)
|
||||
{
|
||||
double some_floats[] = {
|
||||
1.0501, -10.4e12, 5E+10,
|
||||
#ifdef STB__clex_hex_floats
|
||||
0x1.0p+24, 0xff.FP-8, 0x1p-23,
|
||||
#endif
|
||||
4.
|
||||
};
|
||||
|
||||
printf("test %d",1); // https://github.com/nothings/stb/issues/13
|
||||
}
|
||||
|
||||
@ -803,7 +899,7 @@ int main(int argc, char **argv)
|
||||
}
|
||||
fclose(f);
|
||||
|
||||
stb_c_lexer_init(&lex, text, text+len, (char *) malloc(1<<16), 1<<16);
|
||||
stb_c_lexer_init(&lex, text, text+len, (char *) malloc(0x10000), 0x10000);
|
||||
while (stb_c_lexer_get_token(&lex)) {
|
||||
if (lex.token == CLEX_parse_error) {
|
||||
printf("\n<<<PARSE ERROR>>>\n");
|
||||
|
||||
Loading…
Reference in New Issue
Block a user