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.
diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index 207ecdd0..721db8f 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -14,22 +14,6 @@
#ifndef WITHOUT_COMPLEX
-/* Precisions used by repr() and str(), respectively.
-
- The repr() precision (17 significant decimal digits) is the minimal number
- that is guaranteed to have enough precision so that if the number is read
- back in the exact same binary value is recreated. This is true for IEEE
- floating point by design, and also happens to work for all other modern
- hardware.
-
- The str() precision is chosen so that in most cases, the rounding noise
- created by various operations is suppressed, while giving plenty of
- precision for practical use.
-*/
-
-#define PREC_REPR 17
-#define PREC_STR 12
-
/* elementary operations on complex numbers */
static Py_complex c_1 = {1., 0.};
@@ -345,71 +329,114 @@
}
-static void
-complex_to_buf(char *buf, int bufsz, PyComplexObject *v, int precision)
+static PyObject *
+complex_format(PyComplexObject *v, char format_code)
{
- char format[32];
- if (v->cval.real == 0.) {
- if (!Py_IS_FINITE(v->cval.imag)) {
- if (Py_IS_NAN(v->cval.imag))
- strncpy(buf, "nan*j", 6);
- else if (copysign(1, v->cval.imag) == 1)
- strncpy(buf, "inf*j", 6);
- else
- strncpy(buf, "-inf*j", 7);
- }
- else {
- PyOS_snprintf(format, sizeof(format), "%%.%ig", precision);
- PyOS_ascii_formatd(buf, bufsz - 1, format, v->cval.imag);
- strncat(buf, "j", 1);
- }
- } else {
- char re[64], im[64];
- /* Format imaginary part with sign, real part without */
- if (!Py_IS_FINITE(v->cval.real)) {
- if (Py_IS_NAN(v->cval.real))
- strncpy(re, "nan", 4);
- /* else if (copysign(1, v->cval.real) == 1) */
- else if (v->cval.real > 0)
- strncpy(re, "inf", 4);
- else
- strncpy(re, "-inf", 5);
- }
- else {
- PyOS_snprintf(format, sizeof(format), "%%.%ig", precision);
- PyOS_ascii_formatd(re, sizeof(re), format, v->cval.real);
- }
- if (!Py_IS_FINITE(v->cval.imag)) {
- if (Py_IS_NAN(v->cval.imag))
- strncpy(im, "+nan*", 6);
- /* else if (copysign(1, v->cval.imag) == 1) */
- else if (v->cval.imag > 0)
- strncpy(im, "+inf*", 6);
- else
- strncpy(im, "-inf*", 6);
- }
- else {
- PyOS_snprintf(format, sizeof(format), "%%+.%ig", precision);
- PyOS_ascii_formatd(im, sizeof(im), format, v->cval.imag);
- }
- PyOS_snprintf(buf, bufsz, "(%s%sj)", re, im);
- }
+ PyObject *result = NULL;
+ Py_ssize_t len;
+
+ /* If these are non-NULL, they'll need to be freed. */
+ char *pre = NULL;
+ char *pim = NULL;
+ char *buf = NULL;
+
+ /* These do not need to be freed. They're either aliases for pim
+ and pre, or pointers to constants. */
+ char *re = NULL;
+ char *im = NULL;
+ char *lead = "";
+ char *tail = "";
+
+
+ if (v->cval.real == 0.) {
+ re = "";
+ if (!Py_IS_FINITE(v->cval.imag)) {
+ if (Py_IS_NAN(v->cval.imag))
+ im = "nan*";
+ else if (copysign(1, v->cval.imag) == 1)
+ im = "inf*";
+ else
+ im = "-inf*";
+ }
+ else {
+ pim = PyOS_double_to_string(v->cval.imag, format_code,
+ 0, 0, NULL);
+ if (!pim) {
+ PyErr_NoMemory();
+ goto done;
+ }
+ im = pim;
+ }
+ } else {
+ /* Format imaginary part with sign, real part without */
+ if (!Py_IS_FINITE(v->cval.real)) {
+ if (Py_IS_NAN(v->cval.real))
+ re = "nan";
+ /* else if (copysign(1, v->cval.real) == 1) */
+ else if (v->cval.real > 0)
+ re = "inf";
+ else
+ re = "-inf";
+ }
+ else {
+ pre = PyOS_double_to_string(v->cval.real, format_code,
+ 0, 0, NULL);
+ if (!pre) {
+ PyErr_NoMemory();
+ goto done;
+ }
+ re = pre;
+ }
+
+ if (!Py_IS_FINITE(v->cval.imag)) {
+ if (Py_IS_NAN(v->cval.imag))
+ im = "+nan*";
+ /* else if (copysign(1, v->cval.imag) == 1) */
+ else if (v->cval.imag > 0)
+ im = "+inf*";
+ else
+ im = "-inf*";
+ }
+ else {
+ pim = PyOS_double_to_string(v->cval.imag, format_code,
+ 0, Py_DTSF_SIGN, NULL);
+ if (!pim) {
+ PyErr_NoMemory();
+ goto done;
+ }
+ im = pim;
+ }
+ lead = "(";
+ tail = ")";
+ }
+ /* Alloc the final buffer. Add one for the "j" in the format string, and
+ one for the trailing zero. */
+ len = strlen(lead) + strlen(re) + strlen(im) + strlen(tail) + 2;
+ buf = PyMem_Malloc(len);
+ if (!buf) {
+ PyErr_NoMemory();
+ goto done;
+ }
+ PyOS_snprintf(buf, len, "%s%s%sj%s", lead, re, im, tail);
+ result = PyUnicode_FromString(buf);
+done:
+ PyMem_Free(pim);
+ PyMem_Free(pre);
+ PyMem_Free(buf);
+
+ return result;
}
static PyObject *
complex_repr(PyComplexObject *v)
{
- char buf[100];
- complex_to_buf(buf, sizeof(buf), v, PREC_REPR);
- return PyUnicode_FromString(buf);
+ return complex_format(v, 'r');
}
static PyObject *
complex_str(PyComplexObject *v)
{
- char buf[100];
- complex_to_buf(buf, sizeof(buf), v, PREC_STR);
- return PyUnicode_FromString(buf);
+ return complex_format(v, 's');
}
static long