diff options
Diffstat (limited to 'src/pugixpath.cpp')
| -rw-r--r-- | src/pugixpath.cpp | 104 |
1 files changed, 85 insertions, 19 deletions
diff --git a/src/pugixpath.cpp b/src/pugixpath.cpp index 8e35478..dfc5637 100644 --- a/src/pugixpath.cpp +++ b/src/pugixpath.cpp @@ -332,34 +332,100 @@ namespace return (value != 0 && !is_nan(value));
}
+ // gets mantissa digits in the form of 0.xxxxx with 0. implied and the exponent
+ void convert_number_to_mantissa_exponent(double value, char* buffer, char** out_mantissa, int* out_exponent)
+ {
+ // get a scientific notation value with IEEE DBL_DIG decimals
+ sprintf(buffer, "%.15e", value);
+
+ // get the exponent (possibly negative)
+ char* exponent_string = strchr(buffer, 'e');
+ assert(exponent_string);
+
+ int exponent = atoi(exponent_string + 1);
+
+ // extract mantissa string: skip sign
+ char* mantissa = buffer[0] == '-' ? buffer + 1 : buffer;
+ assert(mantissa[0] != '0' && mantissa[1] == '.');
+
+ // divide mantissa by 10 to eliminate integer part
+ mantissa[1] = mantissa[0];
+ mantissa++;
+ exponent++;
+
+ // remove extra mantissa digits and zero-terminate mantissa
+ char* mantissa_end = exponent_string;
+
+ while (mantissa != mantissa_end && *(mantissa_end - 1) == '0') --mantissa_end;
+
+ *mantissa_end = 0;
+
+ // fill results
+ *out_mantissa = mantissa;
+ *out_exponent = exponent;
+ }
+
string_t convert_number_to_string(double value)
{
+ // try special number conversion
const char_t* special = convert_number_to_string_special(value);
if (special) return special;
-
- char buf[512];
- sprintf(buf, "%f", value);
-
- // trim trailing zeros after decimal point
- if (strchr(buf, '.'))
+
+ // get mantissa + exponent form
+ char mantissa_buffer[64];
+
+ char* mantissa;
+ int exponent;
+ convert_number_to_mantissa_exponent(value, mantissa_buffer, &mantissa, &exponent);
+
+ // make the number!
+ char_t result[512];
+ char_t* s = result;
+
+ // sign
+ if (value < 0) *s++ = '-';
+
+ // integer part
+ if (exponent <= 0)
{
- char* ptr = buf + strlen(buf) - 1;
- for (; *ptr == '0'; --ptr) ;
+ *s++ = '0';
+ }
+ else
+ {
+ while (exponent > 0)
+ {
+ assert(*mantissa == 0 || (unsigned)(*mantissa - '0') <= 9);
+ *s++ = *mantissa ? *mantissa++ : '0';
+ exponent--;
+ }
+ }
- // trim leftover decimal point (for integer numbers)
- if (*ptr == '.') --ptr;
+ // fractional part
+ if (*mantissa)
+ {
+ // decimal point
+ *s++ = '.';
- *(ptr+1) = 0;
+ // extra zeroes from negative exponent
+ while (exponent < 0)
+ {
+ *s++ = '0';
+ exponent++;
+ }
+
+ // extra mantissa digits
+ while (*mantissa)
+ {
+ assert((unsigned)(*mantissa - '0') <= 9);
+ *s++ = *mantissa++;
+ }
}
- #ifdef PUGIXML_WCHAR_MODE
- wchar_t wbuf[512];
- impl::widen_ascii(wbuf, buf);
-
- return string_t(wbuf);
- #else
- return string_t(buf);
- #endif
+ // zero-terminate
+ assert(s < result + sizeof(result) / sizeof(result[0]));
+ *s = 0;
+
+ return string_t(result);
}
bool check_string_to_number_format(const char_t* string)
|