harfbuzz/src/hb-number-parser.hh

241 lines
5.2 KiB
C++

#line 1 "hb-number-parser.rl"
/*
* Copyright © 2019 Ebrahim Byagowi
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
*/
#ifndef HB_NUMBER_PARSER_HH
#define HB_NUMBER_PARSER_HH
#include "hb.hh"
#include <float.h>
#line 37 "hb-number-parser.hh"
static const unsigned char _double_parser_trans_keys[] = {
0u, 0u, 43u, 57u, 46u, 57u, 48u, 57u, 43u, 57u, 48u, 57u, 48u, 101u, 48u, 57u,
46u, 101u, 0
};
static const char _double_parser_key_spans[] = {
0, 15, 12, 10, 15, 10, 54, 10,
56
};
static const unsigned char _double_parser_index_offsets[] = {
0, 0, 16, 29, 40, 56, 67, 122,
133
};
static const char _double_parser_indicies[] = {
0, 1, 2, 3, 1, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4,
1, 3, 1, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 1, 5, 5,
5, 5, 5, 5, 5, 5, 5, 5,
1, 6, 1, 7, 1, 1, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8,
1, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 1, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 9, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 9, 1, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 1, 3, 1,
4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 9, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 9, 1, 0
};
static const char _double_parser_trans_targs[] = {
2, 0, 2, 3, 8, 6, 5, 5,
7, 4
};
static const char _double_parser_trans_actions[] = {
0, 0, 1, 0, 2, 3, 0, 4,
5, 0
};
static const int double_parser_start = 1;
static const int double_parser_first_final = 6;
static const int double_parser_error = 0;
static const int double_parser_en_main = 1;
#line 70 "hb-number-parser.rl"
/* Works only for n < 512 */
static inline double
_pow10 (unsigned int exponent)
{
static const double _powers_of_10[] =
{
1.0e+256,
1.0e+128,
1.0e+64,
1.0e+32,
1.0e+16,
1.0e+8,
10000.,
100.,
10.
};
unsigned int mask = 1 << (ARRAY_LENGTH (_powers_of_10) - 1);
double result = 1;
for (const double *power = _powers_of_10; mask; ++power, mask >>= 1)
if (exponent & mask) result *= *power;
return result;
}
static inline double
strtod_rl (const char *buf, char **end_ptr)
{
const char *p, *pe;
double value = 0;
double frac = 0;
double frac_count = 0;
unsigned int exp = 0;
bool neg = false, exp_neg = false, exp_overflow = false;
const unsigned long long MAX_FRACT = 0xFFFFFFFFFFFFFull; /* 1^52-1 */
const unsigned int MAX_EXP = 0x7FFu; /* 1^11-1 */
p = buf;
pe = p + strlen (p);
while (p < pe && ISSPACE (*p))
p++;
int cs;
#line 142 "hb-number-parser.hh"
{
cs = double_parser_start;
}
#line 147 "hb-number-parser.hh"
{
int _slen;
int _trans;
const unsigned char *_keys;
const char *_inds;
if ( p == pe )
goto _test_eof;
if ( cs == 0 )
goto _out;
_resume:
_keys = _double_parser_trans_keys + (cs<<1);
_inds = _double_parser_indicies + _double_parser_index_offsets[cs];
_slen = _double_parser_key_spans[cs];
_trans = _inds[ _slen > 0 && _keys[0] <=(*p) &&
(*p) <= _keys[1] ?
(*p) - _keys[0] : _slen ];
cs = _double_parser_trans_targs[_trans];
if ( _double_parser_trans_actions[_trans] == 0 )
goto _again;
switch ( _double_parser_trans_actions[_trans] ) {
case 1:
#line 39 "hb-number-parser.rl"
{ neg = true; }
break;
case 4:
#line 40 "hb-number-parser.rl"
{ exp_neg = true; }
break;
case 2:
#line 42 "hb-number-parser.rl"
{
value = value * 10. + ((*p) - '0');
}
break;
case 3:
#line 45 "hb-number-parser.rl"
{
if (likely (frac <= MAX_FRACT / 10))
{
frac = frac * 10. + ((*p) - '0');
++frac_count;
}
}
break;
case 5:
#line 52 "hb-number-parser.rl"
{
if (likely (exp * 10 + ((*p) - '0') <= MAX_EXP))
exp = exp * 10 + ((*p) - '0');
else
exp_overflow = true;
}
break;
#line 205 "hb-number-parser.hh"
}
_again:
if ( cs == 0 )
goto _out;
if ( ++p != pe )
goto _resume;
_test_eof: {}
_out: {}
}
#line 116 "hb-number-parser.rl"
*end_ptr = (char *) p;
if (frac_count) value += frac / _pow10 (frac_count);
if (neg) value *= -1.;
if (unlikely (exp_overflow))
{
if (value == 0) return value;
if (exp_neg) return neg ? -DBL_MIN : DBL_MIN;
else return neg ? -DBL_MAX : DBL_MAX;
}
if (exp)
{
if (exp_neg) value /= _pow10 (exp);
else value *= _pow10 (exp);
}
return value;
}
#endif /* HB_NUMBER_PARSER_HH */