1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
/*
* 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>
%%{
machine double_parser;
alphtype unsigned char;
write data;
action see_neg { neg = true; }
action see_exp_neg { exp_neg = true; }
action add_int {
value = value * 10. + (fc - '0');
}
action add_frac {
if (likely (frac <= MAX_FRACT / 10))
{
frac = frac * 10. + (fc - '0');
++frac_count;
}
}
action add_exp {
if (likely (exp * 10 + (fc - '0') <= MAX_EXP))
exp = exp * 10 + (fc - '0');
else
exp_overflow = true;
}
num = [0-9]+;
main := (
(
(('+'|'-'@see_neg)? num @add_int) ('.' num @add_frac)?
|
(('+'|'-'@see_neg)? '.' num @add_frac)
)
(('e'|'E') (('+'|'-'@see_exp_neg)? num @add_exp))?
);
}%%
/* 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;
%%{
write init;
write exec;
}%%
*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 */
|
