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The other half of Issue #1580: use short float repr where possible.
Addresses the float -> string conversion, using David Gay's code which was added in Mark Dickinson's checkin r71663. Also addresses these, which are intertwined with the short repr changes: - Issue #5772: format(1e100, '<') produces '1e+100', not '1.0e+100' - Issue #5515: 'n' formatting with commas no longer works poorly with leading zeros. - PEP 378 Format Specifier for Thousands Separator: implemented for floats.
This commit is contained in:
Eric Smith
parent
b08a53a99d
commit
0923d1d8d7
16 changed files with 1491 additions and 830 deletions
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@ -8792,43 +8792,14 @@ getnextarg(PyObject *args, Py_ssize_t arglen, Py_ssize_t *p_argidx)
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return NULL;
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}
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static Py_ssize_t
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strtounicode(Py_UNICODE *buffer, const char *charbuffer)
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static void
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strtounicode(Py_UNICODE *buffer, const char *charbuffer, Py_ssize_t len)
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{
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register Py_ssize_t i;
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Py_ssize_t len = strlen(charbuffer);
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for (i = len - 1; i >= 0; i--)
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buffer[i] = (Py_UNICODE) charbuffer[i];
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return len;
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}
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static int
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doubletounicode(Py_UNICODE *buffer, size_t len, const char *format, double x)
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{
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Py_ssize_t result;
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PyOS_ascii_formatd((char *)buffer, len, format, x);
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result = strtounicode(buffer, (char *)buffer);
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return Py_SAFE_DOWNCAST(result, Py_ssize_t, int);
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}
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#if 0
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static int
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longtounicode(Py_UNICODE *buffer, size_t len, const char *format, long x)
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{
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Py_ssize_t result;
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PyOS_snprintf((char *)buffer, len, format, x);
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result = strtounicode(buffer, (char *)buffer);
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return Py_SAFE_DOWNCAST(result, Py_ssize_t, int);
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}
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#endif
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/* XXX To save some code duplication, formatfloat/long/int could have been
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shared with stringobject.c, converting from 8-bit to Unicode after the
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formatting is done. */
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static int
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formatfloat(Py_UNICODE *buf,
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size_t buflen,
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@ -8837,54 +8808,59 @@ formatfloat(Py_UNICODE *buf,
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int type,
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PyObject *v)
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{
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/* fmt = '%#.' + `prec` + `type`
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worst case length = 3 + 10 (len of INT_MAX) + 1 = 14 (use 20)*/
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char fmt[20];
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/* eric.smith: To minimize disturbances in PyUnicode_Format (the
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only caller of this routine), I'm going to keep the existing
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API to this function. That means that we'll allocate memory and
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then copy back into the supplied buffer. But that's better than
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all of the changes that would be required in PyUnicode_Format
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because it does lots of memory management tricks. */
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char* p = NULL;
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int result = -1;
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double x;
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Py_ssize_t len;
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x = PyFloat_AsDouble(v);
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if (x == -1.0 && PyErr_Occurred())
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return -1;
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goto done;
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if (prec < 0)
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prec = 6;
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/* make sure that the decimal representation of precision really does
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need at most 10 digits: platforms with sizeof(int) == 8 exist! */
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if (prec > 0x7fffffffL) {
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PyErr_SetString(PyExc_OverflowError,
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"outrageously large precision "
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"for formatted float");
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return -1;
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goto done;
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}
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if (type == 'f' && fabs(x) >= 1e50)
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type = 'g';
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/* Worst case length calc to ensure no buffer overrun:
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'g' formats:
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fmt = %#.<prec>g
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buf = '-' + [0-9]*prec + '.' + 'e+' + (longest exp
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for any double rep.)
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len = 1 + prec + 1 + 2 + 5 = 9 + prec
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'f' formats:
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buf = '-' + [0-9]*x + '.' + [0-9]*prec (with x < 50)
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len = 1 + 50 + 1 + prec = 52 + prec
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If prec=0 the effective precision is 1 (the leading digit is
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always given), therefore increase the length by one.
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*/
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if (((type == 'g' || type == 'G') &&
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buflen <= (size_t)10 + (size_t)prec) ||
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(type == 'f' && buflen <= (size_t)53 + (size_t)prec)) {
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((type == 'f' || type == 'F') &&
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buflen <= (size_t)53 + (size_t)prec)) {
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PyErr_SetString(PyExc_OverflowError,
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"formatted float is too long (precision too large?)");
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return -1;
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goto done;
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}
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PyOS_snprintf(fmt, sizeof(fmt), "%%%s.%d%c",
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(flags&F_ALT) ? "#" : "",
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prec, type);
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return doubletounicode(buf, buflen, fmt, x);
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p = PyOS_double_to_string(x, type, prec,
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(flags & F_ALT) ? Py_DTSF_ALT : 0, NULL);
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len = strlen(p);
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if (len+1 >= buflen) {
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/* Caller supplied buffer is not large enough. */
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PyErr_NoMemory();
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goto done;
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}
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strtounicode(buf, p, len);
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result = Py_SAFE_DOWNCAST(len, Py_ssize_t, int);
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done:
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PyMem_Free(p);
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return result;
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}
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static PyObject*
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@ -8903,84 +8879,6 @@ formatlong(PyObject *val, int flags, int prec, int type)
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return result;
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}
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#if 0
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static int
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formatint(Py_UNICODE *buf,
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size_t buflen,
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int flags,
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int prec,
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int type,
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PyObject *v)
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{
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/* fmt = '%#.' + `prec` + 'l' + `type`
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* worst case length = 3 + 19 (worst len of INT_MAX on 64-bit machine)
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* + 1 + 1
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* = 24
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*/
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char fmt[64]; /* plenty big enough! */
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char *sign;
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long x;
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x = PyLong_AsLong(v);
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if (x == -1 && PyErr_Occurred())
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return -1;
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if (x < 0 && type == 'u') {
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type = 'd';
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}
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if (x < 0 && (type == 'x' || type == 'X' || type == 'o'))
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sign = "-";
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else
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sign = "";
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if (prec < 0)
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prec = 1;
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/* buf = '+'/'-'/'' + '0'/'0x'/'' + '[0-9]'*max(prec, len(x in octal))
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* worst case buf = '-0x' + [0-9]*prec, where prec >= 11
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*/
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if (buflen <= 14 || buflen <= (size_t)3 + (size_t)prec) {
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PyErr_SetString(PyExc_OverflowError,
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"formatted integer is too long (precision too large?)");
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return -1;
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}
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if ((flags & F_ALT) &&
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(type == 'x' || type == 'X' || type == 'o')) {
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/* When converting under %#o, %#x or %#X, there are a number
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* of issues that cause pain:
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* - for %#o, we want a different base marker than C
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* - when 0 is being converted, the C standard leaves off
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* the '0x' or '0X', which is inconsistent with other
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* %#x/%#X conversions and inconsistent with Python's
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* hex() function
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* - there are platforms that violate the standard and
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* convert 0 with the '0x' or '0X'
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* (Metrowerks, Compaq Tru64)
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* - there are platforms that give '0x' when converting
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* under %#X, but convert 0 in accordance with the
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* standard (OS/2 EMX)
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*
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* We can achieve the desired consistency by inserting our
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* own '0x' or '0X' prefix, and substituting %x/%X in place
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* of %#x/%#X.
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*
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* Note that this is the same approach as used in
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* formatint() in stringobject.c
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*/
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PyOS_snprintf(fmt, sizeof(fmt), "%s0%c%%.%dl%c",
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sign, type, prec, type);
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}
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else {
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PyOS_snprintf(fmt, sizeof(fmt), "%s%%%s.%dl%c",
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sign, (flags&F_ALT) ? "#" : "",
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prec, type);
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}
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if (sign[0])
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return longtounicode(buf, buflen, fmt, -x);
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else
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return longtounicode(buf, buflen, fmt, x);
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}
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#endif
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static int
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formatchar(Py_UNICODE *buf,
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size_t buflen,
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@ -9359,8 +9257,6 @@ PyObject *PyUnicode_Format(PyObject *format,
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case 'F':
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case 'g':
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case 'G':
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if (c == 'F')
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c = 'f';
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pbuf = formatbuf;
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len = formatfloat(pbuf, sizeof(formatbuf)/sizeof(Py_UNICODE),
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flags, prec, c, v);
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