// Written in the D programming language.
/*
Helper functions for formatting floating point numbers.
Copyright: Copyright The D Language Foundation 2019 -
License: $(HTTP boost.org/LICENSE_1_0.txt, Boost License 1.0).
Authors: Bernhard Seckinger
Source: $(PHOBOSSRC std/format/internal/floats.d)
*/
module std.format.internal.floats;
import std.format.spec : FormatSpec;
// wrapper for unittests
private auto printFloat(T, Char)(const(T) val, FormatSpec!Char f)
if (is(T == float) || is(T == double)
|| (is(T == real) && (T.mant_dig == double.mant_dig || T.mant_dig == 64)))
{
import std.array : appender;
auto w = appender!string();
printFloat(w, val, f);
return w.data;
}
package(std.format) void printFloat(Writer, T, Char)(auto ref Writer w, const(T) val, FormatSpec!Char f)
if (is(T == float) || is(T == double)
|| (is(T == real) && (T.mant_dig == double.mant_dig || T.mant_dig == 64)))
{
import std.math.operations : extractBitpattern, FloatingPointBitpattern;
auto bp = extractBitpattern(val);
ulong mnt = bp.mantissa;
int exp = bp.exponent;
string sgn = bp.negative ? "-" : "";
if (sgn == "" && f.flPlus) sgn = "+";
if (sgn == "" && f.flSpace) sgn = " ";
assert(f.spec == 'a' || f.spec == 'A'
|| f.spec == 'e' || f.spec == 'E'
|| f.spec == 'f' || f.spec == 'F'
|| f.spec == 'g' || f.spec == 'G', "unsupported format specifier");
bool is_upper = f.spec == 'A' || f.spec == 'E' || f.spec=='F' || f.spec=='G';
// special treatment for nan and inf
if (exp == T.max_exp)
{
import std.format.internal.write : writeAligned;
f.flZero = false;
writeAligned(w, sgn, "", (mnt == 0) ? ( is_upper ? "INF" : "inf" ) : ( is_upper ? "NAN" : "nan" ), f);
return;
}
final switch (f.spec)
{
case 'a': case 'A':
printFloatA(w, val, f, sgn, exp, mnt, is_upper);
break;
case 'e': case 'E':
printFloatE!false(w, val, f, sgn, exp, mnt, is_upper);
break;
case 'f': case 'F':
printFloatF!false(w, val, f, sgn, exp, mnt, is_upper);
break;
case 'g': case 'G':
printFloatG(w, val, f, sgn, exp, mnt, is_upper);
break;
}
}
private void printFloatA(Writer, T, Char)(auto ref Writer w, const(T) val,
FormatSpec!Char f, string sgn, int exp, ulong mnt, bool is_upper)
if (is(T == float) || is(T == double)
|| (is(T == real) && (T.mant_dig == double.mant_dig || T.mant_dig == 64)))
{
import std.algorithm.comparison : max;
import std.format.internal.write : writeAligned, PrecisionType;
char[3] prefix;
if (sgn != "") prefix[0] = sgn[0];
prefix[1] = '0';
prefix[2] = is_upper ? 'X' : 'x';
// print exponent
if (mnt == 0)
{
if (f.precision == f.UNSPECIFIED)
f.precision = 0;
writeAligned(w, prefix[1 - sgn.length .. $], "0", ".", is_upper ? "P+0" : "p+0",
f, PrecisionType.fractionalDigits);
return;
}
// save integer part
char first = '0' + ((mnt >> (T.mant_dig - 1)) & 1);
mnt &= (1L << (T.mant_dig - 1)) - 1;
static if (is(T == float) || (is(T == real) && T.mant_dig == 64))
{
mnt <<= 1; // make mnt dividable by 4
enum mant_len = T.mant_dig;
}
else
enum mant_len = T.mant_dig - 1;
static assert(mant_len % 4 == 0, "mantissa with wrong length");
// print full mantissa
char[(mant_len - 1) / 4 + 3] hex_mant;
size_t hex_mant_pos = 2;
size_t pos = mant_len;
auto gap = 39 - 32 * is_upper;
while (pos >= 4 && (mnt & (((1L << (pos - 1)) - 1) << 1) + 1) != 0)
{
pos -= 4;
size_t tmp = (mnt >> pos) & 15;
// For speed reasons the better readable
// ... = tmp < 10 ? ('0' + tmp) : ((is_upper ? 'A' : 'a') + tmp - 10))
// has been replaced with an expression without branches, doing the same
hex_mant[hex_mant_pos++] = cast(char) (tmp + gap * ((tmp + 6) >> 4) + '0');
}
hex_mant[0] = first;
hex_mant[1] = '.';
if (f.precision == f.UNSPECIFIED)
f.precision = cast(int) hex_mant_pos - 2;
auto exp_sgn = exp >= 0 ? '+' : '-';
if (exp < 0) exp = -exp;
static if (is(T == real) && real.mant_dig == 64)
enum max_exp_digits = 8;
else static if (is(T == float))
enum max_exp_digits = 5;
else
enum max_exp_digits = 6;
char[max_exp_digits] exp_str;
size_t exp_pos = max_exp_digits;
do
{
exp_str[--exp_pos] = '0' + exp % 10;
exp /= 10;
} while (exp > 0);
exp_str[--exp_pos] = exp_sgn;
exp_str[--exp_pos] = is_upper ? 'P' : 'p';
if (f.precision < hex_mant_pos - 2)
{
import std.format.internal.write : RoundingClass, round;
RoundingClass rc;
if (hex_mant[f.precision + 2] == '0')
rc = RoundingClass.ZERO;
else if (hex_mant[f.precision + 2] < '8')
rc = RoundingClass.LOWER;
else if (hex_mant[f.precision + 2] > '8')
rc = RoundingClass.UPPER;
else
rc = RoundingClass.FIVE;
if (rc == RoundingClass.ZERO || rc == RoundingClass.FIVE)
{
foreach (i;f.precision + 3 .. hex_mant_pos)
{
if (hex_mant[i] > '0')
{
rc = rc == RoundingClass.ZERO ? RoundingClass.LOWER : RoundingClass.UPPER;
break;
}
}
}
hex_mant_pos = f.precision + 2;
round(hex_mant, 0, hex_mant_pos, rc, sgn == "-", is_upper ? 'F' : 'f');
}
writeAligned(w, prefix[1 - sgn.length .. $], hex_mant[0 .. 1], hex_mant[1 .. hex_mant_pos],
exp_str[exp_pos .. $], f, PrecisionType.fractionalDigits);
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
assert(printFloat(float.nan, f) == "nan");
assert(printFloat(-float.nan, f) == "-nan");
assert(printFloat(float.infinity, f) == "inf");
assert(printFloat(-float.infinity, f) == "-inf");
assert(printFloat(0.0f, f) == "0x0p+0");
assert(printFloat(-0.0f, f) == "-0x0p+0");
assert(printFloat(double.nan, f) == "nan");
assert(printFloat(-double.nan, f) == "-nan");
assert(printFloat(double.infinity, f) == "inf");
assert(printFloat(-double.infinity, f) == "-inf");
assert(printFloat(0.0, f) == "0x0p+0");
assert(printFloat(-0.0, f) == "-0x0p+0");
static if (real.mant_dig > 64)
{
pragma(msg, "printFloat tests disabled because of unsupported `real` format");
}
else
{
assert(printFloat(real.nan, f) == "nan");
assert(printFloat(-real.nan, f) == "-nan");
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(-real.infinity, f) == "-inf");
assert(printFloat(0.0L, f) == "0x0p+0");
assert(printFloat(-0.0L, f) == "-0x0p+0");
}
import std.math.operations : nextUp;
assert(printFloat(nextUp(0.0f), f) == "0x0.000002p-126");
assert(printFloat(float.epsilon, f) == "0x1p-23");
assert(printFloat(float.min_normal, f) == "0x1p-126");
assert(printFloat(float.max, f) == "0x1.fffffep+127");
assert(printFloat(nextUp(0.0), f) == "0x0.0000000000001p-1022");
assert(printFloat(double.epsilon, f) == "0x1p-52");
assert(printFloat(double.min_normal, f) == "0x1p-1022");
assert(printFloat(double.max, f) == "0x1.fffffffffffffp+1023");
static if (real.mant_dig == 64)
{
assert(printFloat(nextUp(0.0L), f) == "0x0.0000000000000002p-16382");
assert(printFloat(real.epsilon, f) == "0x1p-63");
assert(printFloat(real.min_normal, f) == "0x1p-16382");
assert(printFloat(real.max, f) == "0x1.fffffffffffffffep+16383");
}
import std.math.constants : E, PI, PI_2, PI_4, M_1_PI, M_2_PI, M_2_SQRTPI,
LN10, LN2, LOG2, LOG2E, LOG2T, LOG10E, SQRT2, SQRT1_2;
assert(printFloat(cast(float) E, f) == "0x1.5bf0a8p+1");
assert(printFloat(cast(float) PI, f) == "0x1.921fb6p+1");
assert(printFloat(cast(float) PI_2, f) == "0x1.921fb6p+0");
assert(printFloat(cast(float) PI_4, f) == "0x1.921fb6p-1");
assert(printFloat(cast(float) M_1_PI, f) == "0x1.45f306p-2");
assert(printFloat(cast(float) M_2_PI, f) == "0x1.45f306p-1");
assert(printFloat(cast(float) M_2_SQRTPI, f) == "0x1.20dd76p+0");
assert(printFloat(cast(float) LN10, f) == "0x1.26bb1cp+1");
assert(printFloat(cast(float) LN2, f) == "0x1.62e43p-1");
assert(printFloat(cast(float) LOG2, f) == "0x1.344136p-2");
assert(printFloat(cast(float) LOG2E, f) == "0x1.715476p+0");
assert(printFloat(cast(float) LOG2T, f) == "0x1.a934fp+1");
assert(printFloat(cast(float) LOG10E, f) == "0x1.bcb7b2p-2");
assert(printFloat(cast(float) SQRT2, f) == "0x1.6a09e6p+0");
assert(printFloat(cast(float) SQRT1_2, f) == "0x1.6a09e6p-1");
assert(printFloat(cast(double) E, f) == "0x1.5bf0a8b145769p+1");
assert(printFloat(cast(double) PI, f) == "0x1.921fb54442d18p+1");
assert(printFloat(cast(double) PI_2, f) == "0x1.921fb54442d18p+0");
assert(printFloat(cast(double) PI_4, f) == "0x1.921fb54442d18p-1");
assert(printFloat(cast(double) M_1_PI, f) == "0x1.45f306dc9c883p-2");
assert(printFloat(cast(double) M_2_PI, f) == "0x1.45f306dc9c883p-1");
assert(printFloat(cast(double) M_2_SQRTPI, f) == "0x1.20dd750429b6dp+0");
assert(printFloat(cast(double) LN10, f) == "0x1.26bb1bbb55516p+1");
assert(printFloat(cast(double) LN2, f) == "0x1.62e42fefa39efp-1");
assert(printFloat(cast(double) LOG2, f) == "0x1.34413509f79ffp-2");
assert(printFloat(cast(double) LOG2E, f) == "0x1.71547652b82fep+0");
assert(printFloat(cast(double) LOG2T, f) == "0x1.a934f0979a371p+1");
assert(printFloat(cast(double) LOG10E, f) == "0x1.bcb7b1526e50ep-2");
assert(printFloat(cast(double) SQRT2, f) == "0x1.6a09e667f3bcdp+0");
assert(printFloat(cast(double) SQRT1_2, f) == "0x1.6a09e667f3bcdp-1");
static if (real.mant_dig == 64)
{
assert(printFloat(E, f) == "0x1.5bf0a8b145769536p+1");
assert(printFloat(PI, f) == "0x1.921fb54442d1846ap+1");
assert(printFloat(PI_2, f) == "0x1.921fb54442d1846ap+0");
assert(printFloat(PI_4, f) == "0x1.921fb54442d1846ap-1");
assert(printFloat(M_1_PI, f) == "0x1.45f306dc9c882a54p-2");
assert(printFloat(M_2_PI, f) == "0x1.45f306dc9c882a54p-1");
assert(printFloat(M_2_SQRTPI, f) == "0x1.20dd750429b6d11ap+0");
assert(printFloat(LN10, f) == "0x1.26bb1bbb5551582ep+1");
assert(printFloat(LN2, f) == "0x1.62e42fefa39ef358p-1");
assert(printFloat(LOG2, f) == "0x1.34413509f79fef32p-2");
assert(printFloat(LOG2E, f) == "0x1.71547652b82fe178p+0");
assert(printFloat(LOG2T, f) == "0x1.a934f0979a3715fcp+1");
assert(printFloat(LOG10E, f) == "0x1.bcb7b1526e50e32ap-2");
assert(printFloat(SQRT2, f) == "0x1.6a09e667f3bcc908p+0");
assert(printFloat(SQRT1_2, f) == "0x1.6a09e667f3bcc908p-1");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.precision = 3;
assert(printFloat(1.0f, f) == "0x1.000p+0");
assert(printFloat(3.3f, f) == "0x1.a66p+1");
assert(printFloat(2.9f, f) == "0x1.733p+1");
assert(printFloat(1.0, f) == "0x1.000p+0");
assert(printFloat(3.3, f) == "0x1.a66p+1");
assert(printFloat(2.9, f) == "0x1.733p+1");
static if (real.mant_dig == 64)
{
assert(printFloat(1.0L, f) == "0x1.000p+0");
assert(printFloat(3.3L, f) == "0x1.a66p+1");
assert(printFloat(2.9L, f) == "0x1.733p+1");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.precision = 0;
assert(printFloat(1.0f, f) == "0x1p+0");
assert(printFloat(3.3f, f) == "0x2p+1");
assert(printFloat(2.9f, f) == "0x1p+1");
assert(printFloat(1.0, f) == "0x1p+0");
assert(printFloat(3.3, f) == "0x2p+1");
assert(printFloat(2.9, f) == "0x1p+1");
static if (real.mant_dig == 64)
{
assert(printFloat(1.0L, f) == "0x1p+0");
assert(printFloat(3.3L, f) == "0x2p+1");
assert(printFloat(2.9L, f) == "0x1p+1");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.precision = 0;
f.flHash = true;
assert(printFloat(1.0f, f) == "0x1.p+0");
assert(printFloat(3.3f, f) == "0x2.p+1");
assert(printFloat(2.9f, f) == "0x1.p+1");
assert(printFloat(1.0, f) == "0x1.p+0");
assert(printFloat(3.3, f) == "0x2.p+1");
assert(printFloat(2.9, f) == "0x1.p+1");
static if (real.mant_dig == 64)
{
assert(printFloat(1.0L, f) == "0x1.p+0");
assert(printFloat(3.3L, f) == "0x2.p+1");
assert(printFloat(2.9L, f) == "0x1.p+1");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.width = 22;
assert(printFloat(1.0f, f) == " 0x1p+0");
assert(printFloat(3.3f, f) == " 0x1.a66666p+1");
assert(printFloat(2.9f, f) == " 0x1.733334p+1");
assert(printFloat(1.0, f) == " 0x1p+0");
assert(printFloat(3.3, f) == " 0x1.a666666666666p+1");
assert(printFloat(2.9, f) == " 0x1.7333333333333p+1");
static if (real.mant_dig == 64)
{
f.width = 25;
assert(printFloat(1.0L, f) == " 0x1p+0");
assert(printFloat(3.3L, f) == " 0x1.a666666666666666p+1");
assert(printFloat(2.9L, f) == " 0x1.7333333333333334p+1");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.width = 22;
f.flDash = true;
assert(printFloat(1.0f, f) == "0x1p+0 ");
assert(printFloat(3.3f, f) == "0x1.a66666p+1 ");
assert(printFloat(2.9f, f) == "0x1.733334p+1 ");
assert(printFloat(1.0, f) == "0x1p+0 ");
assert(printFloat(3.3, f) == "0x1.a666666666666p+1 ");
assert(printFloat(2.9, f) == "0x1.7333333333333p+1 ");
static if (real.mant_dig == 64)
{
f.width = 25;
assert(printFloat(1.0L, f) == "0x1p+0 ");
assert(printFloat(3.3L, f) == "0x1.a666666666666666p+1 ");
assert(printFloat(2.9L, f) == "0x1.7333333333333334p+1 ");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.width = 22;
f.flZero = true;
assert(printFloat(1.0f, f) == "0x00000000000000001p+0");
assert(printFloat(3.3f, f) == "0x0000000001.a66666p+1");
assert(printFloat(2.9f, f) == "0x0000000001.733334p+1");
assert(printFloat(1.0, f) == "0x00000000000000001p+0");
assert(printFloat(3.3, f) == "0x001.a666666666666p+1");
assert(printFloat(2.9, f) == "0x001.7333333333333p+1");
static if (real.mant_dig == 64)
{
f.width = 25;
assert(printFloat(1.0L, f) == "0x00000000000000000001p+0");
assert(printFloat(3.3L, f) == "0x001.a666666666666666p+1");
assert(printFloat(2.9L, f) == "0x001.7333333333333334p+1");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.width = 22;
f.flPlus = true;
assert(printFloat(1.0f, f) == " +0x1p+0");
assert(printFloat(3.3f, f) == " +0x1.a66666p+1");
assert(printFloat(2.9f, f) == " +0x1.733334p+1");
assert(printFloat(1.0, f) == " +0x1p+0");
assert(printFloat(3.3, f) == " +0x1.a666666666666p+1");
assert(printFloat(2.9, f) == " +0x1.7333333333333p+1");
static if (real.mant_dig == 64)
{
f.width = 25;
assert(printFloat(1.0L, f) == " +0x1p+0");
assert(printFloat(3.3L, f) == " +0x1.a666666666666666p+1");
assert(printFloat(2.9L, f) == " +0x1.7333333333333334p+1");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.width = 22;
f.flDash = true;
f.flSpace = true;
assert(printFloat(1.0f, f) == " 0x1p+0 ");
assert(printFloat(3.3f, f) == " 0x1.a66666p+1 ");
assert(printFloat(2.9f, f) == " 0x1.733334p+1 ");
assert(printFloat(1.0, f) == " 0x1p+0 ");
assert(printFloat(3.3, f) == " 0x1.a666666666666p+1 ");
assert(printFloat(2.9, f) == " 0x1.7333333333333p+1 ");
static if (real.mant_dig == 64)
{
f.width = 25;
assert(printFloat(1.0L, f) == " 0x1p+0 ");
assert(printFloat(3.3L, f) == " 0x1.a666666666666666p+1 ");
assert(printFloat(2.9L, f) == " 0x1.7333333333333334p+1 ");
}
}
@safe unittest
{
import std.math.hardware; // cannot be selective, because FloatingPointControl might not be defined
// std.math's FloatingPointControl isn't available on all target platforms
static if (is(FloatingPointControl))
{
FloatingPointControl fpctrl;
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.precision = 1;
fpctrl.rounding = FloatingPointControl.roundToNearest;
/* tiesAwayFromZero currently not supported
assert(printFloat(0x1.18p0, f) == "0x1.2p+0");
assert(printFloat(0x1.28p0, f) == "0x1.3p+0");
assert(printFloat(0x1.1ap0, f) == "0x1.2p+0");
assert(printFloat(0x1.16p0, f) == "0x1.1p+0");
assert(printFloat(0x1.10p0, f) == "0x1.1p+0");
assert(printFloat(-0x1.18p0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.28p0, f) == "-0x1.3p+0");
assert(printFloat(-0x1.1ap0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.16p0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.10p0, f) == "-0x1.1p+0");
*/
assert(printFloat(0x1.18p0, f) == "0x1.2p+0");
assert(printFloat(0x1.28p0, f) == "0x1.2p+0");
assert(printFloat(0x1.1ap0, f) == "0x1.2p+0");
assert(printFloat(0x1.16p0, f) == "0x1.1p+0");
assert(printFloat(0x1.10p0, f) == "0x1.1p+0");
assert(printFloat(-0x1.18p0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.28p0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.1ap0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.16p0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.10p0, f) == "-0x1.1p+0");
fpctrl.rounding = FloatingPointControl.roundToZero;
assert(printFloat(0x1.18p0, f) == "0x1.1p+0");
assert(printFloat(0x1.28p0, f) == "0x1.2p+0");
assert(printFloat(0x1.1ap0, f) == "0x1.1p+0");
assert(printFloat(0x1.16p0, f) == "0x1.1p+0");
assert(printFloat(0x1.10p0, f) == "0x1.1p+0");
assert(printFloat(-0x1.18p0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.28p0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.1ap0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.16p0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.10p0, f) == "-0x1.1p+0");
fpctrl.rounding = FloatingPointControl.roundUp;
assert(printFloat(0x1.18p0, f) == "0x1.2p+0");
assert(printFloat(0x1.28p0, f) == "0x1.3p+0");
assert(printFloat(0x1.1ap0, f) == "0x1.2p+0");
assert(printFloat(0x1.16p0, f) == "0x1.2p+0");
assert(printFloat(0x1.10p0, f) == "0x1.1p+0");
assert(printFloat(-0x1.18p0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.28p0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.1ap0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.16p0, f) == "-0x1.1p+0");
assert(printFloat(-0x1.10p0, f) == "-0x1.1p+0");
fpctrl.rounding = FloatingPointControl.roundDown;
assert(printFloat(0x1.18p0, f) == "0x1.1p+0");
assert(printFloat(0x1.28p0, f) == "0x1.2p+0");
assert(printFloat(0x1.1ap0, f) == "0x1.1p+0");
assert(printFloat(0x1.16p0, f) == "0x1.1p+0");
assert(printFloat(0x1.10p0, f) == "0x1.1p+0");
assert(printFloat(-0x1.18p0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.28p0, f) == "-0x1.3p+0");
assert(printFloat(-0x1.1ap0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.16p0, f) == "-0x1.2p+0");
assert(printFloat(-0x1.10p0, f) == "-0x1.1p+0");
}
}
// for 100% coverage
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'a';
f.precision = 3;
assert(printFloat(0x1.19f81p0, f) == "0x1.1a0p+0");
assert(printFloat(0x1.19f01p0, f) == "0x1.19fp+0");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'A';
f.precision = 3;
assert(printFloat(0x1.19f81p0, f) == "0X1.1A0P+0");
assert(printFloat(0x1.19f01p0, f) == "0X1.19FP+0");
}
private void printFloatE(bool g, Writer, T, Char)(auto ref Writer w, const(T) val,
FormatSpec!Char f, string sgn, int exp, ulong mnt, bool is_upper)
if (is(T == float) || is(T == double)
|| (is(T == real) && (T.mant_dig == double.mant_dig || T.mant_dig == 64)))
{
import std.format.internal.write : writeAligned, PrecisionType, RoundingClass, round;
static if (!g)
{
if (f.precision == f.UNSPECIFIED)
f.precision = 6;
}
// special treatment for 0.0
if (mnt == 0)
{
static if (g)
writeAligned(w, sgn, "0", ".", "", f, PrecisionType.allDigits);
else
writeAligned(w, sgn, "0", ".", is_upper ? "E+00" : "e+00", f, PrecisionType.fractionalDigits);
return;
}
char[T.mant_dig + T.max_exp] dec_buf;
char[T.max_10_exp.stringof.length + 2] exp_buf;
int final_exp = 0;
RoundingClass rc;
// Depending on exp, we will use one of three algorithms:
//
// Algorithm A: For large exponents (exp >= T.mant_dig)
// Algorithm B: For small exponents (exp < T.mant_dig - 61)
// Algorithm C: For exponents close to 0.
//
// Algorithm A:
// The number to print looks like this: mantissa followed by several zeros.
//
// We know, that there is no fractional part, so we can just use integer division,
// consecutivly dividing by 10 and writing down the remainder from right to left.
// Unfortunately the integer is too large to fit in an ulong, so we use something
// like BigInt: An array of ulongs. We only use 60 bits of that ulongs, because
// this simplifies (and speeds up) the division to come.
//
// For the division we use integer division with reminder for each ulong and put
// the reminder of each step in the first 4 bits of ulong of the next step (think of
// long division for the rationale behind this). The final reminder is the next
// digit (from right to left).
//
// This results in the output we would have for the %f specifier. We now adjust this
// for %e: First we calculate the place, where the exponent should be printed, filling
// up with zeros if needed and second we move the leftmost digit one to the left
// and inserting a dot.
//
// After that we decide on the rounding type, using the digits right of the position,
// where the exponent will be printed (currently they are still there, but will be
// overwritten later).
//
// Algorithm B:
// The number to print looks like this: zero dot several zeros followed by the mantissa
//
// We know, that the number has no integer part. The algorithm consecutivly multiplies
// by 10. The integer part (rounded down) after the multiplication is the next digit
// (from left to right). This integer part is removed after each step.
// Again, the number is represented as an array of ulongs, with only 60 bits used of
// every ulong.
//
// For the multiplication we use normal integer multiplication, which can result in digits
// in the uppermost 4 bits. These 4 digits are the carry which is added to the result
// of the next multiplication and finally the last carry is the next digit.
//
// Other than for the %f specifier, this multiplication is splitted into two almost
// identical parts. The first part lasts as long as we find zeros. We need to do this
// to calculate the correct exponent.
//
// The second part will stop, when only zeros remain or when we've got enough digits
// for the requested precision. In the second case, we have to find out, which rounding
// we have. Aside from special cases we do this by calculating one more digit.
//
// Algorithm C:
// This time, we know, that the integral part and the fractional part each fit into a
// ulong. The mantissa might be partially in both parts or completely in the fractional
// part.
//
// We first calculate the integral part by consecutive division by 10. Depending on the
// precision this might result in more digits, than we need. In that case we calculate
// the position of the exponent and the rounding type.
//
// If there is no integral part, we need to find the first non zero digit. We do this by
// consecutive multiplication by 10, saving the first non zero digit followed by a dot.
//
// In either case, we continue filling up with the fractional part until we have enough
// digits. If still necessary, we decide the rounding type, mainly by looking at the
// next digit.
size_t right = 1;
size_t start = 1;
size_t left = 1;
static if (is(T == real) && real.mant_dig == 64)
{
enum small_bound = 0;
enum max_buf = 275;
}
else
{
enum small_bound = T.mant_dig - 61;
static if (is(T == float))
enum max_buf = 4;
else
enum max_buf = 18;
}
ulong[max_buf] bigbuf;
if (exp >= T.mant_dig)
{
start = left = right = dec_buf.length;
// large number without fractional digits
//
// As this number does not fit in a ulong, we use an array of ulongs. We only use 60 of the 64 bits,
// because this makes it much more easy to implement the division by 10.
int count = exp / 60 + 1;
// only the first few ulongs contain the mantiassa. The rest are zeros.
int lower = 60 - (exp - T.mant_dig + 1) % 60;
static if (is(T == real) && real.mant_dig == 64)
{
// for x87 reals, the lowest ulong may contain more than 60 bits,
// because the mantissa is 63 (>60) bits long
// therefore we need one ulong less
if (lower <= 3) count--;
}
// saved in big endian format
ulong[] mybig = bigbuf[0 .. count];
if (lower < T.mant_dig)
{
mybig[0] = mnt >> lower;
mybig[1] = (mnt & ((1L << lower) - 1)) << 60 - lower;
}
else
mybig[0] = (mnt & ((1L << lower) - 1)) << 60 - lower;
// Generation of digits by consecutive division with reminder by 10.
int msu = 0; // Most significant ulong; when it get's zero, we can ignore it further on
while (msu < count - 1 || mybig[$ - 1] != 0)
{
ulong mod = 0;
foreach (i;msu .. count)
{
mybig[i] |= mod << 60;
mod = mybig[i] % 10;
mybig[i] /= 10;
}
if (mybig[msu] == 0)
++msu;
dec_buf[--left] = cast(byte) ('0' + mod);
++final_exp;
}
--final_exp;
static if (g)
start = left + f.precision;
else
start = left + f.precision + 1;
// move leftmost digit one more left and add dot between
dec_buf[left - 1] = dec_buf[left];
dec_buf[left] = '.';
--left;
// rounding type
if (start >= right)
rc = RoundingClass.ZERO;
else if (dec_buf[start] != '0' && dec_buf[start] != '5')
rc = dec_buf[start] > '5' ? RoundingClass.UPPER : RoundingClass.LOWER;
else
{
rc = dec_buf[start] == '5' ? RoundingClass.FIVE : RoundingClass.ZERO;
foreach (i; start + 1 .. right)
if (dec_buf[i] > '0')
{
rc = rc == RoundingClass.FIVE ? RoundingClass.UPPER : RoundingClass.LOWER;
break;
}
}
if (start < right) right = start;
}
else if (exp < small_bound)
{
// small number without integer digits
//
// Again this number does not fit in a ulong and we use an array of ulongs. And again we
// only use 60 bits, because this simplifies the multiplication by 10.
int count = (T.mant_dig - exp - 2) / 60 + 1;
// saved in little endian format
ulong[] mybig = bigbuf[0 .. count];
// only the last few ulongs contain the mantiassa. Because of little endian
// format these are the ulongs at index 0 and 1 (and 2 in case of x87 reals).
// The rest are zeros.
int upper = 60 - (-exp - 1) % 60;
static if (is(T == real) && real.mant_dig == 64)
{
if (upper < 4)
{
mybig[0] = (mnt & ((1L << (4 - upper)) - 1)) << 56 + upper;
mybig[1] = (mnt >> (4 - upper)) & ((1L << 60) - 1);
mybig[2] = mnt >> 64 - upper;
}
else
{
mybig[0] = (mnt & ((1L << (T.mant_dig - upper)) - 1)) << 60 - (T.mant_dig - upper);
mybig[1] = mnt >> (T.mant_dig - upper);
}
}
else
{
if (upper < T.mant_dig)
{
mybig[0] = (mnt & ((1L << (T.mant_dig - upper)) - 1)) << 60 - (T.mant_dig - upper);
mybig[1] = mnt >> (T.mant_dig - upper);
}
else
mybig[0] = mnt << (upper - T.mant_dig);
}
int lsu = 0; // Least significant ulong; when it get's zero, we can ignore it further on
// adding zeros, until we reach first nonzero
while (lsu < count - 1 || mybig[$ - 1]!=0)
{
ulong over = 0;
foreach (i; lsu .. count)
{
mybig[i] = mybig[i] * 10 + over;
over = mybig[i] >> 60;
mybig[i] &= (1L << 60) - 1;
}
if (mybig[lsu] == 0)
++lsu;
--final_exp;
if (over != 0)
{
dec_buf[right++] = cast(byte) ('0' + over);
dec_buf[right++] = '.';
break;
}
}
// adding more digits
static if (g)
start = right - 1;
else
start = right;
while ((lsu < count - 1 || mybig[$ - 1] != 0) && right - start < f.precision)
{
ulong over = 0;
foreach (i;lsu .. count)
{
mybig[i] = mybig[i] * 10 + over;
over = mybig[i] >> 60;
mybig[i] &= (1L << 60) - 1;
}
if (mybig[lsu] == 0)
++lsu;
dec_buf[right++] = cast(byte) ('0' + over);
}
// rounding type
if (lsu >= count - 1 && mybig[count - 1] == 0)
rc = RoundingClass.ZERO;
else if (lsu == count - 1 && mybig[lsu] == 1L << 59)
rc = RoundingClass.FIVE;
else
{
ulong over = 0;
foreach (i;lsu .. count)
{
mybig[i] = mybig[i] * 10 + over;
over = mybig[i] >> 60;
mybig[i] &= (1L << 60) - 1;
}
rc = over >= 5 ? RoundingClass.UPPER : RoundingClass.LOWER;
}
}
else
{
// medium sized number, probably with integer and fractional digits
// this is fastest, because both parts fit into a ulong each
ulong int_part = mnt >> (T.mant_dig - 1 - exp);
ulong frac_part = mnt & ((1L << (T.mant_dig - 1 - exp)) - 1);
// for x87 reals the mantiassa might be up to 3 bits too long
// we need to save these bits as a tail and handle this separately
static if (is(T == real) && real.mant_dig == 64)
{
ulong tail = 0;
ulong tail_length = 0;
if (exp < 3)
{
tail = frac_part & ((1L << (3 - exp)) - 1);
tail_length = 3 - exp;
frac_part >>= 3 - exp;
exp = 3;
}
}
start = 0;
// could we already decide on the rounding mode in the integer part?
bool found = false;
if (int_part > 0)
{
import core.bitop : bsr;
left = right = int_part.bsr * 100 / 332 + 4;
// integer part, if there is something to print
while (int_part >= 10)
{
dec_buf[--left] = '0' + (int_part % 10);
int_part /= 10;
++final_exp;
++start;
}
dec_buf[--left] = '.';
dec_buf[--left] = cast(byte) ('0' + int_part);
static if (g)
auto limit = f.precision + 1;
else
auto limit = f.precision + 2;
if (right - left > limit)
{
auto old_right = right;
right = left + limit;
if (dec_buf[right] == '5' || dec_buf[right] == '0')
{
rc = dec_buf[right] == '5' ? RoundingClass.FIVE : RoundingClass.ZERO;
if (frac_part != 0)
rc = rc == RoundingClass.FIVE ? RoundingClass.UPPER : RoundingClass.LOWER;
else
foreach (i;right + 1 .. old_right)
if (dec_buf[i] > '0')
{
rc = rc == RoundingClass.FIVE ? RoundingClass.UPPER : RoundingClass.LOWER;
break;
}
}
else
rc = dec_buf[right] > '5' ? RoundingClass.UPPER : RoundingClass.LOWER;
found = true;
}
}
else
{
// fractional part, skipping leading zeros
while (frac_part != 0)
{
--final_exp;
frac_part *= 10;
static if (is(T == real) && real.mant_dig == 64)
{
if (tail_length > 0)
{
// together this is *= 10;
tail *= 5;
tail_length--;
frac_part += tail >> tail_length;
if (tail_length > 0)
tail &= (1L << tail_length) - 1;
}
}
auto tmp = frac_part >> (T.mant_dig - 1 - exp);
frac_part &= ((1L << (T.mant_dig - 1 - exp)) - 1);
if (tmp > 0)
{
dec_buf[right++] = cast(byte) ('0' + tmp);
dec_buf[right++] = '.';
break;
}
}
rc = RoundingClass.ZERO;
}
static if (g)
size_t limit = f.precision - 1;
else
size_t limit = f.precision;
// the fractional part after the zeros
while (frac_part != 0 && start < limit)
{
frac_part *= 10;
static if (is(T == real) && real.mant_dig == 64)
{
if (tail_length > 0)
{
// together this is *= 10;
tail *= 5;
tail_length--;
frac_part += tail >> tail_length;
if (tail_length > 0)
tail &= (1L << tail_length) - 1;
}
}
dec_buf[right++] = cast(byte) ('0' + (frac_part >> (T.mant_dig - 1 - exp)));
frac_part &= ((1L << (T.mant_dig - 1 - exp)) - 1);
++start;
}
static if (g)
limit = right - left - 1;
else
limit = start;
// rounding mode, if not allready known
if (frac_part != 0 && !found)
{
frac_part *= 10;
auto nextDigit = frac_part >> (T.mant_dig - 1 - exp);
frac_part &= ((1L << (T.mant_dig - 1 - exp)) - 1);
if (nextDigit == 5 && frac_part == 0)
rc = RoundingClass.FIVE;
else if (nextDigit >= 5)
rc = RoundingClass.UPPER;
else
rc = RoundingClass.LOWER;
}
}
if (round(dec_buf, left, right, rc, sgn == "-"))
{
left--;
right--;
dec_buf[left + 2] = dec_buf[left + 1];
dec_buf[left + 1] = '.';
final_exp++;
}
// printing exponent
auto neg = final_exp < 0;
if (neg) final_exp = -final_exp;
size_t exp_pos = exp_buf.length;
do
{
exp_buf[--exp_pos] = '0' + final_exp%10;
final_exp /= 10;
} while (final_exp > 0);
if (exp_buf.length - exp_pos == 1)
exp_buf[--exp_pos] = '0';
exp_buf[--exp_pos] = neg ? '-' : '+';
exp_buf[--exp_pos] = is_upper ? 'E' : 'e';
while (right > left + 1 && dec_buf[right - 1] == '0') right--;
if (right == left + 1)
dec_buf[right++] = '.';
static if (g)
writeAligned(w, sgn, dec_buf[left .. left + 1], dec_buf[left + 1 .. right],
exp_buf[exp_pos .. $], f, PrecisionType.allDigits);
else
writeAligned(w, sgn, dec_buf[left .. left + 1], dec_buf[left + 1 .. right],
exp_buf[exp_pos .. $], f, PrecisionType.fractionalDigits);
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
assert(printFloat(float.nan, f) == "nan");
assert(printFloat(-float.nan, f) == "-nan");
assert(printFloat(float.infinity, f) == "inf");
assert(printFloat(-float.infinity, f) == "-inf");
assert(printFloat(0.0f, f) == "0.000000e+00");
assert(printFloat(-0.0f, f) == "-0.000000e+00");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "9.999946e-41");
assert(printFloat(cast(float) -1e-40, f) == "-9.999946e-41");
assert(printFloat(1e-30f, f) == "1.000000e-30");
assert(printFloat(-1e-30f, f) == "-1.000000e-30");
assert(printFloat(1e-10f, f) == "1.000000e-10");
assert(printFloat(-1e-10f, f) == "-1.000000e-10");
assert(printFloat(0.1f, f) == "1.000000e-01");
assert(printFloat(-0.1f, f) == "-1.000000e-01");
assert(printFloat(10.0f, f) == "1.000000e+01");
assert(printFloat(-10.0f, f) == "-1.000000e+01");
assert(printFloat(1e30f, f) == "1.000000e+30");
assert(printFloat(-1e30f, f) == "-1.000000e+30");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "1.401298e-45");
assert(printFloat(nextDown(-0.0f), f) == "-1.401298e-45");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
f.width = 20;
f.precision = 10;
assert(printFloat(float.nan, f) == " nan");
assert(printFloat(-float.nan, f) == " -nan");
assert(printFloat(float.infinity, f) == " inf");
assert(printFloat(-float.infinity, f) == " -inf");
assert(printFloat(0.0f, f) == " 0.0000000000e+00");
assert(printFloat(-0.0f, f) == " -0.0000000000e+00");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == " 9.9999461011e-41");
assert(printFloat(cast(float) -1e-40, f) == " -9.9999461011e-41");
assert(printFloat(1e-30f, f) == " 1.0000000032e-30");
assert(printFloat(-1e-30f, f) == " -1.0000000032e-30");
assert(printFloat(1e-10f, f) == " 1.0000000134e-10");
assert(printFloat(-1e-10f, f) == " -1.0000000134e-10");
assert(printFloat(0.1f, f) == " 1.0000000149e-01");
assert(printFloat(-0.1f, f) == " -1.0000000149e-01");
assert(printFloat(10.0f, f) == " 1.0000000000e+01");
assert(printFloat(-10.0f, f) == " -1.0000000000e+01");
assert(printFloat(1e30f, f) == " 1.0000000150e+30");
assert(printFloat(-1e30f, f) == " -1.0000000150e+30");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == " 1.4012984643e-45");
assert(printFloat(nextDown(-0.0f), f) == " -1.4012984643e-45");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
f.width = 20;
f.precision = 10;
f.flDash = true;
assert(printFloat(float.nan, f) == "nan ");
assert(printFloat(-float.nan, f) == "-nan ");
assert(printFloat(float.infinity, f) == "inf ");
assert(printFloat(-float.infinity, f) == "-inf ");
assert(printFloat(0.0f, f) == "0.0000000000e+00 ");
assert(printFloat(-0.0f, f) == "-0.0000000000e+00 ");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "9.9999461011e-41 ");
assert(printFloat(cast(float) -1e-40, f) == "-9.9999461011e-41 ");
assert(printFloat(1e-30f, f) == "1.0000000032e-30 ");
assert(printFloat(-1e-30f, f) == "-1.0000000032e-30 ");
assert(printFloat(1e-10f, f) == "1.0000000134e-10 ");
assert(printFloat(-1e-10f, f) == "-1.0000000134e-10 ");
assert(printFloat(0.1f, f) == "1.0000000149e-01 ");
assert(printFloat(-0.1f, f) == "-1.0000000149e-01 ");
assert(printFloat(10.0f, f) == "1.0000000000e+01 ");
assert(printFloat(-10.0f, f) == "-1.0000000000e+01 ");
assert(printFloat(1e30f, f) == "1.0000000150e+30 ");
assert(printFloat(-1e30f, f) == "-1.0000000150e+30 ");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "1.4012984643e-45 ");
assert(printFloat(nextDown(-0.0f), f) == "-1.4012984643e-45 ");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
f.width = 20;
f.precision = 10;
f.flZero = true;
assert(printFloat(float.nan, f) == " nan");
assert(printFloat(-float.nan, f) == " -nan");
assert(printFloat(float.infinity, f) == " inf");
assert(printFloat(-float.infinity, f) == " -inf");
assert(printFloat(0.0f, f) == "00000.0000000000e+00");
assert(printFloat(-0.0f, f) == "-0000.0000000000e+00");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "00009.9999461011e-41");
assert(printFloat(cast(float) -1e-40, f) == "-0009.9999461011e-41");
assert(printFloat(1e-30f, f) == "00001.0000000032e-30");
assert(printFloat(-1e-30f, f) == "-0001.0000000032e-30");
assert(printFloat(1e-10f, f) == "00001.0000000134e-10");
assert(printFloat(-1e-10f, f) == "-0001.0000000134e-10");
assert(printFloat(0.1f, f) == "00001.0000000149e-01");
assert(printFloat(-0.1f, f) == "-0001.0000000149e-01");
assert(printFloat(10.0f, f) == "00001.0000000000e+01");
assert(printFloat(-10.0f, f) == "-0001.0000000000e+01");
assert(printFloat(1e30f, f) == "00001.0000000150e+30");
assert(printFloat(-1e30f, f) == "-0001.0000000150e+30");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "00001.4012984643e-45");
assert(printFloat(nextDown(-0.0f), f) == "-0001.4012984643e-45");
}
@safe unittest
{
import std.math.hardware; // cannot be selective, because FloatingPointControl might not be defined
// std.math's FloatingPointControl isn't available on all target platforms
static if (is(FloatingPointControl))
{
FloatingPointControl fpctrl;
auto f = FormatSpec!dchar("");
f.spec = 'e';
f.precision = 1;
fpctrl.rounding = FloatingPointControl.roundToNearest;
/*
assert(printFloat(11.5f, f) == "1.2e+01");
assert(printFloat(12.5f, f) == "1.3e+01");
assert(printFloat(11.7f, f) == "1.2e+01");
assert(printFloat(11.3f, f) == "1.1e+01");
assert(printFloat(11.0f, f) == "1.1e+01");
assert(printFloat(-11.5f, f) == "-1.2e+01");
assert(printFloat(-12.5f, f) == "-1.3e+01");
assert(printFloat(-11.7f, f) == "-1.2e+01");
assert(printFloat(-11.3f, f) == "-1.1e+01");
assert(printFloat(-11.0f, f) == "-1.1e+01");
*/
assert(printFloat(11.5f, f) == "1.2e+01");
assert(printFloat(12.5f, f) == "1.2e+01");
assert(printFloat(11.7f, f) == "1.2e+01");
assert(printFloat(11.3f, f) == "1.1e+01");
assert(printFloat(11.0f, f) == "1.1e+01");
assert(printFloat(-11.5f, f) == "-1.2e+01");
assert(printFloat(-12.5f, f) == "-1.2e+01");
assert(printFloat(-11.7f, f) == "-1.2e+01");
assert(printFloat(-11.3f, f) == "-1.1e+01");
assert(printFloat(-11.0f, f) == "-1.1e+01");
fpctrl.rounding = FloatingPointControl.roundToZero;
assert(printFloat(11.5f, f) == "1.1e+01");
assert(printFloat(12.5f, f) == "1.2e+01");
assert(printFloat(11.7f, f) == "1.1e+01");
assert(printFloat(11.3f, f) == "1.1e+01");
assert(printFloat(11.0f, f) == "1.1e+01");
assert(printFloat(-11.5f, f) == "-1.1e+01");
assert(printFloat(-12.5f, f) == "-1.2e+01");
assert(printFloat(-11.7f, f) == "-1.1e+01");
assert(printFloat(-11.3f, f) == "-1.1e+01");
assert(printFloat(-11.0f, f) == "-1.1e+01");
fpctrl.rounding = FloatingPointControl.roundUp;
assert(printFloat(11.5f, f) == "1.2e+01");
assert(printFloat(12.5f, f) == "1.3e+01");
assert(printFloat(11.7f, f) == "1.2e+01");
assert(printFloat(11.3f, f) == "1.2e+01");
assert(printFloat(11.0f, f) == "1.1e+01");
assert(printFloat(-11.5f, f) == "-1.1e+01");
assert(printFloat(-12.5f, f) == "-1.2e+01");
assert(printFloat(-11.7f, f) == "-1.1e+01");
assert(printFloat(-11.3f, f) == "-1.1e+01");
assert(printFloat(-11.0f, f) == "-1.1e+01");
fpctrl.rounding = FloatingPointControl.roundDown;
assert(printFloat(11.5f, f) == "1.1e+01");
assert(printFloat(12.5f, f) == "1.2e+01");
assert(printFloat(11.7f, f) == "1.1e+01");
assert(printFloat(11.3f, f) == "1.1e+01");
assert(printFloat(11.0f, f) == "1.1e+01");
assert(printFloat(-11.5f, f) == "-1.2e+01");
assert(printFloat(-12.5f, f) == "-1.3e+01");
assert(printFloat(-11.7f, f) == "-1.2e+01");
assert(printFloat(-11.3f, f) == "-1.2e+01");
assert(printFloat(-11.0f, f) == "-1.1e+01");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
assert(printFloat(double.nan, f) == "nan");
assert(printFloat(-double.nan, f) == "-nan");
assert(printFloat(double.infinity, f) == "inf");
assert(printFloat(-double.infinity, f) == "-inf");
assert(printFloat(0.0, f) == "0.000000e+00");
assert(printFloat(-0.0, f) == "-0.000000e+00");
// / 1000 needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(1e-307 / 1000, f) == "1.000000e-310");
assert(printFloat(-1e-307 / 1000, f) == "-1.000000e-310");
assert(printFloat(1e-30, f) == "1.000000e-30");
assert(printFloat(-1e-30, f) == "-1.000000e-30");
assert(printFloat(1e-10, f) == "1.000000e-10");
assert(printFloat(-1e-10, f) == "-1.000000e-10");
assert(printFloat(0.1, f) == "1.000000e-01");
assert(printFloat(-0.1, f) == "-1.000000e-01");
assert(printFloat(10.0, f) == "1.000000e+01");
assert(printFloat(-10.0, f) == "-1.000000e+01");
assert(printFloat(1e300, f) == "1.000000e+300");
assert(printFloat(-1e300, f) == "-1.000000e+300");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0), f) == "4.940656e-324");
assert(printFloat(nextDown(-0.0), f) == "-4.940656e-324");
}
@safe unittest
{
static if (real.mant_dig > 64)
{
pragma(msg, "printFloat tests disabled because of unsupported `real` format");
}
else
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
assert(printFloat(real.nan, f) == "nan");
assert(printFloat(-real.nan, f) == "-nan");
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(-real.infinity, f) == "-inf");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
import std.math.operations : nextUp;
double eps = nextUp(0.0);
f.precision = 1000;
assert(printFloat(eps, f) ==
"4.9406564584124654417656879286822137236505980261432476442558568250067550727020875186529983636163599"
~"23797965646954457177309266567103559397963987747960107818781263007131903114045278458171678489821036"
~"88718636056998730723050006387409153564984387312473397273169615140031715385398074126238565591171026"
~"65855668676818703956031062493194527159149245532930545654440112748012970999954193198940908041656332"
~"45247571478690147267801593552386115501348035264934720193790268107107491703332226844753335720832431"
~"93609238289345836806010601150616980975307834227731832924790498252473077637592724787465608477820373"
~"44696995336470179726777175851256605511991315048911014510378627381672509558373897335989936648099411"
~"64205702637090279242767544565229087538682506419718265533447265625000000000000000000000000000000000"
~"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
~"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
~"000000000000000000000e-324");
f.precision = 50;
assert(printFloat(double.max, f) ==
"1.79769313486231570814527423731704356798070567525845e+308");
assert(printFloat(double.epsilon, f) ==
"2.22044604925031308084726333618164062500000000000000e-16");
f.precision = 10;
assert(printFloat(1.0/3.0, f) == "3.3333333333e-01");
assert(printFloat(1.0/7.0, f) == "1.4285714286e-01");
assert(printFloat(1.0/9.0, f) == "1.1111111111e-01");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
f.precision = 15;
import std.math.constants : E, PI, PI_2, PI_4, M_1_PI, M_2_PI, M_2_SQRTPI,
LN10, LN2, LOG2, LOG2E, LOG2T, LOG10E, SQRT2, SQRT1_2;
assert(printFloat(cast(double) E, f) == "2.718281828459045e+00");
assert(printFloat(cast(double) PI, f) == "3.141592653589793e+00");
assert(printFloat(cast(double) PI_2, f) == "1.570796326794897e+00");
assert(printFloat(cast(double) PI_4, f) == "7.853981633974483e-01");
assert(printFloat(cast(double) M_1_PI, f) == "3.183098861837907e-01");
assert(printFloat(cast(double) M_2_PI, f) == "6.366197723675814e-01");
assert(printFloat(cast(double) M_2_SQRTPI, f) == "1.128379167095513e+00");
assert(printFloat(cast(double) LN10, f) == "2.302585092994046e+00");
assert(printFloat(cast(double) LN2, f) == "6.931471805599453e-01");
assert(printFloat(cast(double) LOG2, f) == "3.010299956639812e-01");
assert(printFloat(cast(double) LOG2E, f) == "1.442695040888963e+00");
assert(printFloat(cast(double) LOG2T, f) == "3.321928094887362e+00");
assert(printFloat(cast(double) LOG10E, f) == "4.342944819032518e-01");
assert(printFloat(cast(double) SQRT2, f) == "1.414213562373095e+00");
assert(printFloat(cast(double) SQRT1_2, f) == "7.071067811865476e-01");
}
// for 100% coverage
@safe unittest
{
import std.math.hardware; // cannot be selective, because FloatingPointControl might not be defined
auto f = FormatSpec!dchar("");
f.spec = 'E';
f.precision = 80;
assert(printFloat(5.62776e+12f, f) ==
"5.62775982080000000000000000000000000000000000000000000000000000000000000000000000E+12");
f.precision = 49;
assert(printFloat(2.5997869e-12f, f) ==
"2.5997869221999758693186777236405760049819946289062E-12");
f.precision = 6;
assert(printFloat(-1.1418613e+07f, f) == "-1.141861E+07");
assert(printFloat(-1.368281e+07f, f) == "-1.368281E+07");
f.precision = 1;
assert(printFloat(-245.666f, f) == "-2.5E+02");
static if (is(FloatingPointControl))
{
FloatingPointControl fpctrl;
fpctrl.rounding = FloatingPointControl.roundUp;
f.precision = 0;
assert(printFloat(709422.0f, f) == "8E+05");
}
}
@safe unittest
{
static if (real.mant_dig > 64)
{
pragma(msg, "printFloat tests disabled because of unsupported `real` format");
}
else
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
assert(printFloat(real.nan, f) == "nan");
assert(printFloat(-real.nan, f) == "-nan");
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(-real.infinity, f) == "-inf");
assert(printFloat(0.0L, f) == "0.000000e+00");
assert(printFloat(-0.0L, f) == "-0.000000e+00");
}
static if (real.mant_dig == 64)
{
assert(printFloat(1e-4940L, f) == "1.000000e-4940");
assert(printFloat(-1e-4940L, f) == "-1.000000e-4940");
assert(printFloat(1e-30L, f) == "1.000000e-30");
assert(printFloat(-1e-30L, f) == "-1.000000e-30");
assert(printFloat(1e-10L, f) == "1.000000e-10");
assert(printFloat(-1e-10L, f) == "-1.000000e-10");
assert(printFloat(0.1L, f) == "1.000000e-01");
assert(printFloat(-0.1L, f) == "-1.000000e-01");
assert(printFloat(10.0L, f) == "1.000000e+01");
assert(printFloat(-10.0L, f) == "-1.000000e+01");
version (Windows) {} // issue 20972
else
{
assert(printFloat(1e4000L, f) == "1.000000e+4000");
assert(printFloat(-1e4000L, f) == "-1.000000e+4000");
}
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0L), f) == "3.645200e-4951");
assert(printFloat(nextDown(-0.0L), f) == "-3.645200e-4951");
}
}
@safe unittest
{
import std.exception : assertCTFEable;
import std.math.exponential : log2;
import std.math.operations : nextDown;
assertCTFEable!(
{
// log2 is broken for x87-reals on some computers in CTFE
// the following tests excludes these computers from the tests
// (issue 21757)
enum test = cast(int) log2(3.05e2312L);
static if (real.mant_dig == 64 && test == 7681)
{
auto f = FormatSpec!dchar("");
f.spec = 'e';
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(10.0L, f) == "1.000000e+01");
assert(printFloat(2.6080L, f) == "2.608000e+00");
assert(printFloat(3.05e2312L, f) == "3.050000e+2312");
f.precision = 60;
assert(printFloat(2.65e-54L, f) ==
"2.650000000000000000059009987400547013941028940935296547599415e-54");
/*
commented out, because CTFE is currently too slow for 5000 digits with extreme values
f.precision = 5000;
auto result2 = printFloat(1.2119e-4822L, f);
assert(result2.length == 5008);
assert(result2[$ - 20 .. $] == "60729486595339e-4822");
auto result3 = printFloat(real.min_normal, f);
assert(result3.length == 5008);
assert(result3[$ - 20 .. $] == "20781410082267e-4932");
auto result4 = printFloat(real.min_normal.nextDown, f);
assert(result4.length == 5008);
assert(result4[$ - 20 .. $] == "81413263331006e-4932");
*/
}
});
}
private void printFloatF(bool g, Writer, T, Char)(auto ref Writer w, const(T) val,
FormatSpec!Char f, string sgn, int exp, ulong mnt, bool is_upper)
if (is(T == float) || is(T == double)
|| (is(T == real) && (T.mant_dig == double.mant_dig || T.mant_dig == 64)))
{
import std.format.internal.write : writeAligned, PrecisionType, RoundingClass, round;
static if (!g)
{
if (f.precision == f.UNSPECIFIED)
f.precision = 6;
}
// special treatment for 0.0
if (exp == 0 && mnt == 0)
{
writeAligned(w, sgn, "0", ".", "", f, PrecisionType.fractionalDigits);
return;
}
char[T.max_exp + T.mant_dig + 1] dec_buf;
RoundingClass rc;
// Depending on exp, we will use one of three algorithms:
//
// Algorithm A: For large exponents (exp >= T.mant_dig)
// Algorithm B: For small exponents (exp < T.mant_dig - 61)
// Algorithm C: For exponents close to 0.
//
// Algorithm A:
// The number to print looks like this: mantissa followed by several zeros.
//
// We know, that there is no fractional part, so we can just use integer division,
// consecutivly dividing by 10 and writing down the remainder from right to left.
// Unfortunately the integer is too large to fit in an ulong, so we use something
// like BigInt: An array of ulongs. We only use 60 bits of that ulongs, because
// this simplifies (and speeds up) the division to come.
//
// For the division we use integer division with reminder for each ulong and put
// the reminder of each step in the first 4 bits of ulong of the next step (think of
// long division for the rationale behind this). The final reminder is the next
// digit (from right to left).
//
// Algorithm B:
// The number to print looks like this: zero dot several zeros followed by the mantissa
//
// We know, that the number has no integer part. The algorithm consecutivly multiplies
// by 10. The integer part (rounded down) after the multiplication is the next digit
// (from left to right). This integer part is removed after each step.
// Again, the number is represented as an array of ulongs, with only 60 bits used of
// every ulong.
//
// For the multiplication we use normal integer multiplication, which can result in digits
// in the uppermost 4 bits. These 4 digits are the carry which is added to the result
// of the next multiplication and finally the last carry is the next digit.
//
// The calculation will stop, when only zeros remain or when we've got enough digits
// for the requested precision. In the second case, we have to find out, which rounding
// we have. Aside from special cases we do this by calculating one more digit.
//
// Algorithm C:
// This time, we know, that the integral part and the fractional part each fit into a
// ulong. The mantissa might be partially in both parts or completely in the fractional
// part.
//
// We first calculate the integral part by consecutive division by 10. Then we calculate
// the fractional part by consecutive multiplication by 10. Again only until we have enough
// digits. Finally, we decide the rounding type, mainly by looking at the next digit.
static if (is(T == real) && real.mant_dig == 64)
{
enum small_bound = 0;
enum max_buf = 275;
}
else
{
enum small_bound = T.mant_dig - 61;
static if (is(T == float))
enum max_buf = 4;
else
enum max_buf = 18;
}
size_t start = 2;
size_t left = 2;
size_t right = 2;
ulong[max_buf] bigbuf;
if (exp >= T.mant_dig)
{
left = start = dec_buf.length - 1;
right = dec_buf.length;
dec_buf[start] = '.';
// large number without fractional digits
//
// As this number does not fit in a ulong, we use an array of ulongs. We only use 60 of the 64 bits,
// because this makes it much more easy to implement the division by 10.
int count = exp / 60 + 1;
// only the first few ulongs contain the mantiassa. The rest are zeros.
int lower = 60 - (exp - T.mant_dig + 1) % 60;
static if (is(T == real) && real.mant_dig == 64)
{
// for x87 reals, the lowest ulong may contain more than 60 bits,
// because the mantissa is 63 (>60) bits long
// therefore we need one ulong less
if (lower <= 3) count--;
}
// saved in big endian format
ulong[] mybig = bigbuf[0 .. count];
if (lower < T.mant_dig)
{
mybig[0] = mnt >> lower;
mybig[1] = (mnt & ((1L << lower) - 1)) << 60 - lower;
}
else
mybig[0] = (mnt & ((1L << lower) - 1)) << 60 - lower;
// Generation of digits by consecutive division with reminder by 10.
int msu = 0; // Most significant ulong; when it get's zero, we can ignore it furtheron
while (msu < count - 1 || mybig[$ - 1] != 0)
{
ulong mod = 0;
foreach (i;msu .. count)
{
mybig[i] |= mod << 60;
mod = mybig[i] % 10;
mybig[i] /= 10;
}
if (mybig[msu] == 0)
++msu;
dec_buf[--left] = cast(byte) ('0' + mod);
}
rc = RoundingClass.ZERO;
}
else if (exp < small_bound)
{
// small number without integer digits
//
// Again this number does not fit in a ulong and we use an array of ulongs. And again we
// only use 60 bits, because this simplifies the multiplication by 10.
int count = (T.mant_dig - exp - 2) / 60 + 1;
// saved in little endian format
ulong[] mybig = bigbuf[0 .. count];
// only the last few ulongs contain the mantiassa. Because of little endian
// format these are the ulongs at index 0 and 1 (and 2 in case of x87 reals).
// The rest are zeros.
int upper = 60 - (-exp - 1) % 60;
static if (is(T == real) && real.mant_dig == 64)
{
if (upper < 4)
{
mybig[0] = (mnt & ((1L << (4 - upper)) - 1)) << 56 + upper;
mybig[1] = (mnt >> (4 - upper)) & ((1L << 60) - 1);
mybig[2] = mnt >> 64 - upper;
}
else
{
mybig[0] = (mnt & ((1L << (T.mant_dig - upper)) - 1)) << 60 - (T.mant_dig - upper);
mybig[1] = mnt >> (T.mant_dig - upper);
}
}
else
{
if (upper < T.mant_dig)
{
mybig[0] = (mnt & ((1L << (T.mant_dig - upper)) - 1)) << 60 - (T.mant_dig - upper);
mybig[1] = mnt >> (T.mant_dig - upper);
}
else
mybig[0] = mnt << (upper - T.mant_dig);
}
dec_buf[--left] = '0'; // 0 left of the dot
dec_buf[right++] = '.';
static if (g)
{
// precision starts at first non zero, so we move start
// to the right, until we found first non zero, thus avoiding
// a premature break of the loop
bool found = false;
start = left + 1;
}
// Generation of digits by consecutive multiplication by 10.
int lsu = 0; // Least significant ulong; when it get's zero, we can ignore it furtheron
while ((lsu < count - 1 || mybig[$ - 1] != 0) && right - start - 1 < f.precision)
{
ulong over = 0;
foreach (i;lsu .. count)
{
mybig[i] = mybig[i] * 10 + over;
over = mybig[i] >> 60;
mybig[i] &= (1L << 60) - 1;
}
if (mybig[lsu] == 0)
++lsu;
dec_buf[right++] = cast(byte) ('0' + over);
static if (g)
{
if (dec_buf[right - 1] != '0')
found = true;
else if (!found)
start++;
}
}
static if (g) start = 2;
if (lsu >= count - 1 && mybig[count - 1] == 0)
rc = RoundingClass.ZERO;
else if (lsu == count - 1 && mybig[lsu] == 1L << 59)
rc = RoundingClass.FIVE;
else
{
ulong over = 0;
foreach (i;lsu .. count)
{
mybig[i] = mybig[i] * 10 + over;
over = mybig[i] >> 60;
mybig[i] &= (1L << 60) - 1;
}
rc = over >= 5 ? RoundingClass.UPPER : RoundingClass.LOWER;
}
}
else
{
// medium sized number, probably with integer and fractional digits
// this is fastest, because both parts fit into a ulong each
ulong int_part = mnt >> (T.mant_dig - 1 - exp);
ulong frac_part = mnt & ((1L << (T.mant_dig - 1 - exp)) - 1);
// for x87 reals the mantiassa might be up to 3 bits too long
// we need to save these bits as a tail and handle this separately
static if (is(T == real) && real.mant_dig == 64)
{
ulong tail = 0;
ulong tail_length = 0;
if (exp < 3)
{
tail = frac_part & ((1L << (3 - exp)) - 1);
tail_length = 3 - exp;
frac_part >>= 3 - exp;
exp = 3;
}
}
static if (g) auto found = int_part > 0; // searching first non zero
// creating int part
if (int_part == 0)
dec_buf[--left] = '0';
else
{
import core.bitop : bsr;
left = right = start = int_part.bsr * 100 / 332 + 4;
while (int_part > 0)
{
dec_buf[--left] = '0' + (int_part % 10);
int_part /= 10;
}
}
static if (g) size_t save_start = right;
dec_buf[right++] = '.';
// creating frac part
static if (g) start = left + (found ? 0 : 1);
while (frac_part != 0 && right - start - 1 < f.precision)
{
frac_part *= 10;
static if (is(T == real) && real.mant_dig == 64)
{
if (tail_length > 0)
{
// together this is *= 10;
tail *= 5;
tail_length--;
frac_part += tail >> tail_length;
if (tail_length > 0)
tail &= (1L << tail_length) - 1;
}
}
dec_buf[right++] = cast(byte)('0' + (frac_part >> (T.mant_dig - 1 - exp)));
static if (g)
{
if (dec_buf[right - 1] != '0')
found = true;
else if (!found)
start++;
}
frac_part &= ((1L << (T.mant_dig - 1 - exp)) - 1);
}
static if (g) start = save_start;
if (frac_part == 0)
rc = RoundingClass.ZERO;
else
{
frac_part *= 10;
auto nextDigit = frac_part >> (T.mant_dig - 1 - exp);
frac_part &= ((1L << (T.mant_dig - 1 - exp)) - 1);
if (nextDigit == 5 && frac_part == 0)
rc = RoundingClass.FIVE;
else if (nextDigit >= 5)
rc = RoundingClass.UPPER;
else
rc = RoundingClass.LOWER;
}
}
if (round(dec_buf, left, right, rc, sgn == "-")) left--;
while (right > start + 1 && dec_buf[right - 1] == '0') right--;
static if (g)
writeAligned(w, sgn, dec_buf[left .. start], dec_buf[start .. right], "", f, PrecisionType.allDigits);
else
writeAligned(w, sgn, dec_buf[left .. start], dec_buf[start .. right], "", f, PrecisionType.fractionalDigits);
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
assert(printFloat(float.nan, f) == "nan");
assert(printFloat(-float.nan, f) == "-nan");
assert(printFloat(float.infinity, f) == "inf");
assert(printFloat(-float.infinity, f) == "-inf");
assert(printFloat(0.0f, f) == "0.000000");
assert(printFloat(-0.0f, f) == "-0.000000");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "0.000000");
assert(printFloat(cast(float) -1e-40, f) == "-0.000000");
assert(printFloat(1e-30f, f) == "0.000000");
assert(printFloat(-1e-30f, f) == "-0.000000");
assert(printFloat(1e-10f, f) == "0.000000");
assert(printFloat(-1e-10f, f) == "-0.000000");
assert(printFloat(0.1f, f) == "0.100000");
assert(printFloat(-0.1f, f) == "-0.100000");
assert(printFloat(10.0f, f) == "10.000000");
assert(printFloat(-10.0f, f) == "-10.000000");
assert(printFloat(1e30f, f) == "1000000015047466219876688855040.000000");
assert(printFloat(-1e30f, f) == "-1000000015047466219876688855040.000000");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "0.000000");
assert(printFloat(nextDown(-0.0f), f) == "-0.000000");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
f.width = 20;
f.precision = 10;
assert(printFloat(float.nan, f) == " nan");
assert(printFloat(-float.nan, f) == " -nan");
assert(printFloat(float.infinity, f) == " inf");
assert(printFloat(-float.infinity, f) == " -inf");
assert(printFloat(0.0f, f) == " 0.0000000000");
assert(printFloat(-0.0f, f) == " -0.0000000000");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == " 0.0000000000");
assert(printFloat(cast(float) -1e-40, f) == " -0.0000000000");
assert(printFloat(1e-30f, f) == " 0.0000000000");
assert(printFloat(-1e-30f, f) == " -0.0000000000");
assert(printFloat(1e-10f, f) == " 0.0000000001");
assert(printFloat(-1e-10f, f) == " -0.0000000001");
assert(printFloat(0.1f, f) == " 0.1000000015");
assert(printFloat(-0.1f, f) == " -0.1000000015");
assert(printFloat(10.0f, f) == " 10.0000000000");
assert(printFloat(-10.0f, f) == " -10.0000000000");
assert(printFloat(1e30f, f) == "1000000015047466219876688855040.0000000000");
assert(printFloat(-1e30f, f) == "-1000000015047466219876688855040.0000000000");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == " 0.0000000000");
assert(printFloat(nextDown(-0.0f), f) == " -0.0000000000");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
f.width = 20;
f.precision = 10;
f.flDash = true;
assert(printFloat(float.nan, f) == "nan ");
assert(printFloat(-float.nan, f) == "-nan ");
assert(printFloat(float.infinity, f) == "inf ");
assert(printFloat(-float.infinity, f) == "-inf ");
assert(printFloat(0.0f, f) == "0.0000000000 ");
assert(printFloat(-0.0f, f) == "-0.0000000000 ");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "0.0000000000 ");
assert(printFloat(cast(float) -1e-40, f) == "-0.0000000000 ");
assert(printFloat(1e-30f, f) == "0.0000000000 ");
assert(printFloat(-1e-30f, f) == "-0.0000000000 ");
assert(printFloat(1e-10f, f) == "0.0000000001 ");
assert(printFloat(-1e-10f, f) == "-0.0000000001 ");
assert(printFloat(0.1f, f) == "0.1000000015 ");
assert(printFloat(-0.1f, f) == "-0.1000000015 ");
assert(printFloat(10.0f, f) == "10.0000000000 ");
assert(printFloat(-10.0f, f) == "-10.0000000000 ");
assert(printFloat(1e30f, f) == "1000000015047466219876688855040.0000000000");
assert(printFloat(-1e30f, f) == "-1000000015047466219876688855040.0000000000");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "0.0000000000 ");
assert(printFloat(nextDown(-0.0f), f) == "-0.0000000000 ");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
f.width = 20;
f.precision = 10;
f.flZero = true;
assert(printFloat(float.nan, f) == " nan");
assert(printFloat(-float.nan, f) == " -nan");
assert(printFloat(float.infinity, f) == " inf");
assert(printFloat(-float.infinity, f) == " -inf");
assert(printFloat(0.0f, f) == "000000000.0000000000");
assert(printFloat(-0.0f, f) == "-00000000.0000000000");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "000000000.0000000000");
assert(printFloat(cast(float) -1e-40, f) == "-00000000.0000000000");
assert(printFloat(1e-30f, f) == "000000000.0000000000");
assert(printFloat(-1e-30f, f) == "-00000000.0000000000");
assert(printFloat(1e-10f, f) == "000000000.0000000001");
assert(printFloat(-1e-10f, f) == "-00000000.0000000001");
assert(printFloat(0.1f, f) == "000000000.1000000015");
assert(printFloat(-0.1f, f) == "-00000000.1000000015");
assert(printFloat(10.0f, f) == "000000010.0000000000");
assert(printFloat(-10.0f, f) == "-00000010.0000000000");
assert(printFloat(1e30f, f) == "1000000015047466219876688855040.0000000000");
assert(printFloat(-1e30f, f) == "-1000000015047466219876688855040.0000000000");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "000000000.0000000000");
assert(printFloat(nextDown(-0.0f), f) == "-00000000.0000000000");
}
@safe unittest
{
import std.math.hardware; // cannot be selective, because FloatingPointControl might not be defined
// std.math's FloatingPointControl isn't available on all target platforms
static if (is(FloatingPointControl))
{
FloatingPointControl fpctrl;
auto f = FormatSpec!dchar("");
f.spec = 'f';
f.precision = 0;
fpctrl.rounding = FloatingPointControl.roundToNearest;
/*
assert(printFloat(11.5f, f) == "12");
assert(printFloat(12.5f, f) == "13");
assert(printFloat(11.7f, f) == "12");
assert(printFloat(11.3f, f) == "11");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-12");
assert(printFloat(-12.5f, f) == "-13");
assert(printFloat(-11.7f, f) == "-12");
assert(printFloat(-11.3f, f) == "-11");
assert(printFloat(-11.0f, f) == "-11");
*/
assert(printFloat(11.5f, f) == "12");
assert(printFloat(12.5f, f) == "12");
assert(printFloat(11.7f, f) == "12");
assert(printFloat(11.3f, f) == "11");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-12");
assert(printFloat(-12.5f, f) == "-12");
assert(printFloat(-11.7f, f) == "-12");
assert(printFloat(-11.3f, f) == "-11");
assert(printFloat(-11.0f, f) == "-11");
fpctrl.rounding = FloatingPointControl.roundToZero;
assert(printFloat(11.5f, f) == "11");
assert(printFloat(12.5f, f) == "12");
assert(printFloat(11.7f, f) == "11");
assert(printFloat(11.3f, f) == "11");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-11");
assert(printFloat(-12.5f, f) == "-12");
assert(printFloat(-11.7f, f) == "-11");
assert(printFloat(-11.3f, f) == "-11");
assert(printFloat(-11.0f, f) == "-11");
fpctrl.rounding = FloatingPointControl.roundUp;
assert(printFloat(11.5f, f) == "12");
assert(printFloat(12.5f, f) == "13");
assert(printFloat(11.7f, f) == "12");
assert(printFloat(11.3f, f) == "12");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-11");
assert(printFloat(-12.5f, f) == "-12");
assert(printFloat(-11.7f, f) == "-11");
assert(printFloat(-11.3f, f) == "-11");
assert(printFloat(-11.0f, f) == "-11");
fpctrl.rounding = FloatingPointControl.roundDown;
assert(printFloat(11.5f, f) == "11");
assert(printFloat(12.5f, f) == "12");
assert(printFloat(11.7f, f) == "11");
assert(printFloat(11.3f, f) == "11");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-12");
assert(printFloat(-12.5f, f) == "-13");
assert(printFloat(-11.7f, f) == "-12");
assert(printFloat(-11.3f, f) == "-12");
assert(printFloat(-11.0f, f) == "-11");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
assert(printFloat(double.nan, f) == "nan");
assert(printFloat(-double.nan, f) == "-nan");
assert(printFloat(double.infinity, f) == "inf");
assert(printFloat(-double.infinity, f) == "-inf");
assert(printFloat(0.0, f) == "0.000000");
assert(printFloat(-0.0, f) == "-0.000000");
// / 1000 needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(1e-307 / 1000, f) == "0.000000");
assert(printFloat(-1e-307 / 1000, f) == "-0.000000");
assert(printFloat(1e-30, f) == "0.000000");
assert(printFloat(-1e-30, f) == "-0.000000");
assert(printFloat(1e-10, f) == "0.000000");
assert(printFloat(-1e-10, f) == "-0.000000");
assert(printFloat(0.1, f) == "0.100000");
assert(printFloat(-0.1, f) == "-0.100000");
assert(printFloat(10.0, f) == "10.000000");
assert(printFloat(-10.0, f) == "-10.000000");
assert(printFloat(1e300, f) ==
"100000000000000005250476025520442024870446858110815915491585411551180245798890819578637137508044786"
~"404370444383288387817694252323536043057564479218478670698284838720092657580373783023379478809005936"
~"895323497079994508111903896764088007465274278014249457925878882005684283811566947219638686545940054"
~"0160.000000");
assert(printFloat(-1e300, f) ==
"-100000000000000005250476025520442024870446858110815915491585411551180245798890819578637137508044786"
~"404370444383288387817694252323536043057564479218478670698284838720092657580373783023379478809005936"
~"895323497079994508111903896764088007465274278014249457925878882005684283811566947219638686545940054"
~"0160.000000");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0), f) == "0.000000");
assert(printFloat(nextDown(-0.0), f) == "-0.000000");
}
@safe unittest
{
static if (real.mant_dig > 64)
{
pragma(msg, "printFloat tests disabled because of unsupported `real` format");
}
else
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
assert(printFloat(real.nan, f) == "nan");
assert(printFloat(-real.nan, f) == "-nan");
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(-real.infinity, f) == "-inf");
assert(printFloat(0.0L, f) == "0.000000");
assert(printFloat(-0.0L, f) == "-0.000000");
}
static if (real.mant_dig == 64)
{
assert(printFloat(1e-4940L, f) == "0.000000");
assert(printFloat(-1e-4940L, f) == "-0.000000");
assert(printFloat(1e-30L, f) == "0.000000");
assert(printFloat(-1e-30L, f) == "-0.000000");
assert(printFloat(1e-10L, f) == "0.000000");
assert(printFloat(-1e-10L, f) == "-0.000000");
assert(printFloat(0.1L, f) == "0.100000");
assert(printFloat(-0.1L, f) == "-0.100000");
assert(printFloat(10.0L, f) == "10.000000");
assert(printFloat(-10.0L, f) == "-10.000000");
version (Windows) {} // issue 20972
else
{
auto result1 = printFloat(1e4000L, f);
assert(result1.length == 4007 && result1[0 .. 40] == "9999999999999999999965463873099623784932");
auto result2 = printFloat(-1e4000L, f);
assert(result2.length == 4008 && result2[0 .. 40] == "-999999999999999999996546387309962378493");
}
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0L), f) == "0.000000");
assert(printFloat(nextDown(-0.0L), f) == "-0.000000");
}
}
@safe unittest
{
import std.exception : assertCTFEable;
import std.math.exponential : log2;
import std.math.operations : nextDown;
assertCTFEable!(
{
// log2 is broken for x87-reals on some computers in CTFE
// the following tests excludes these computers from the tests
// (issue 21757)
enum test = cast(int) log2(3.05e2312L);
static if (real.mant_dig == 64 && test == 7681)
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(10.0L, f) == "10.000000");
assert(printFloat(2.6080L, f) == "2.608000");
auto result1 = printFloat(3.05e2312L, f);
assert(result1.length == 2320);
assert(result1[0 .. 20] == "30499999999999999999");
f.precision = 60;
assert(printFloat(2.65e-54L, f) ==
"0.000000000000000000000000000000000000000000000000000002650000");
/*
commented out, because CTFE is currently too slow for 5000 digits with extreme values
f.precision = 5000;
auto result2 = printFloat(1.2119e-4822L, f);
assert(result2.length == 5002);
assert(result2[$ - 20 .. $] == "60076763752233836613");
auto result3 = printFloat(real.min_normal, f);
assert(result3.length == 5002);
assert(result3[$ - 20 .. $] == "47124010882722980874");
auto result4 = printFloat(real.min_normal.nextDown, f);
assert(result4.length == 5002);
assert(result4[$ - 20 .. $] == "52925846892214823939");
*/
}
});
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
import std.math.operations : nextUp;
double eps = nextUp(0.0);
f.precision = 1000;
assert(printFloat(eps, f) ==
"0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
~"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
~"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
~"00000000000000000000000000000049406564584124654417656879286822137236505980261432476442558568250067"
~"55072702087518652998363616359923797965646954457177309266567103559397963987747960107818781263007131"
~"90311404527845817167848982103688718636056998730723050006387409153564984387312473397273169615140031"
~"71538539807412623856559117102665855668676818703956031062493194527159149245532930545654440112748012"
~"97099995419319894090804165633245247571478690147267801593552386115501348035264934720193790268107107"
~"49170333222684475333572083243193609238289345836806010601150616980975307834227731832924790498252473"
~"07763759272478746560847782037344696995336470179726777175851256605511991315048911014510378627381672"
~"509558373897335989937");
f.precision = 0;
assert(printFloat(double.max, f) ==
"179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878"
~"17154045895351438246423432132688946418276846754670353751698604991057655128207624549009038932894407"
~"58685084551339423045832369032229481658085593321233482747978262041447231687381771809192998812504040"
~"26184124858368");
f.precision = 50;
assert(printFloat(double.epsilon, f) ==
"0.00000000000000022204460492503130808472633361816406");
f.precision = 10;
assert(printFloat(1.0/3.0, f) == "0.3333333333");
assert(printFloat(1.0/7.0, f) == "0.1428571429");
assert(printFloat(1.0/9.0, f) == "0.1111111111");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
f.precision = 15;
import std.math.constants : E, PI, PI_2, PI_4, M_1_PI, M_2_PI, M_2_SQRTPI,
LN10, LN2, LOG2, LOG2E, LOG2T, LOG10E, SQRT2, SQRT1_2;
assert(printFloat(cast(double) E, f) == "2.718281828459045");
assert(printFloat(cast(double) PI, f) == "3.141592653589793");
assert(printFloat(cast(double) PI_2, f) == "1.570796326794897");
assert(printFloat(cast(double) PI_4, f) == "0.785398163397448");
assert(printFloat(cast(double) M_1_PI, f) == "0.318309886183791");
assert(printFloat(cast(double) M_2_PI, f) == "0.636619772367581");
assert(printFloat(cast(double) M_2_SQRTPI, f) == "1.128379167095513");
assert(printFloat(cast(double) LN10, f) == "2.302585092994046");
assert(printFloat(cast(double) LN2, f) == "0.693147180559945");
assert(printFloat(cast(double) LOG2, f) == "0.301029995663981");
assert(printFloat(cast(double) LOG2E, f) == "1.442695040888963");
assert(printFloat(cast(double) LOG2T, f) == "3.321928094887362");
assert(printFloat(cast(double) LOG10E, f) == "0.434294481903252");
assert(printFloat(cast(double) SQRT2, f) == "1.414213562373095");
assert(printFloat(cast(double) SQRT1_2, f) == "0.707106781186548");
}
// for 100% coverage
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'f';
f.precision = 1;
assert(printFloat(9.99, f) == "10.0");
import std.math.operations : nextUp;
float eps = nextUp(0.0f);
f.precision = 148;
assert(printFloat(eps, f) ==
"0.0000000000000000000000000000000000000000000014012984643248170709237295832899161312802619418765157"
~"717570682838897910826858606014866381883621215820312");
f.precision = 149;
assert(printFloat(eps, f) ==
"0.0000000000000000000000000000000000000000000014012984643248170709237295832899161312802619418765157"
~"7175706828388979108268586060148663818836212158203125");
}
private void printFloatG(Writer, T, Char)(auto ref Writer w, const(T) val,
FormatSpec!Char f, string sgn, int exp, ulong mnt, bool is_upper)
if (is(T == float) || is(T == double)
|| (is(T == real) && (T.mant_dig == double.mant_dig || T.mant_dig == 64)))
{
import core.math : abs = fabs;
if (f.precision == f.UNSPECIFIED)
f.precision = 6;
if (f.precision == 0)
f.precision = 1;
import std.math.hardware;
import std.format.internal.write : RoundingMode;
auto rm = RoundingMode.toNearestTiesToEven;
if (!__ctfe)
{
// std.math's FloatingPointControl isn't available on all target platforms
static if (is(FloatingPointControl))
{
switch (FloatingPointControl.rounding)
{
case FloatingPointControl.roundUp:
rm = RoundingMode.up;
break;
case FloatingPointControl.roundDown:
rm = RoundingMode.down;
break;
case FloatingPointControl.roundToZero:
rm = RoundingMode.toZero;
break;
case FloatingPointControl.roundToNearest:
rm = RoundingMode.toNearestTiesToEven;
break;
default: assert(false, "Unknown floating point rounding mode");
}
}
}
bool useE = false;
final switch (rm)
{
case RoundingMode.up:
useE = abs(val) >= 10.0 ^^ f.precision - (val > 0 ? 1 : 0)
|| abs(val) < 0.0001 - (val > 0 ? (10.0 ^^ (-4 - f.precision)) : 0);
break;
case RoundingMode.down:
useE = abs(val) >= 10.0 ^^ f.precision - (val < 0 ? 1 : 0)
|| abs(val) < 0.0001 - (val < 0 ? (10.0 ^^ (-4 - f.precision)) : 0);
break;
case RoundingMode.toZero:
useE = abs(val) >= 10.0 ^^ f.precision
|| abs(val) < 0.0001;
break;
case RoundingMode.toNearestTiesToEven:
case RoundingMode.toNearestTiesAwayFromZero:
useE = abs(val) >= 10.0 ^^ f.precision - 0.5
|| abs(val) < 0.0001 - 0.5 * (10.0 ^^ (-4 - f.precision));
break;
}
if (useE)
return printFloatE!true(w, val, f, sgn, exp, mnt, is_upper);
else
return printFloatF!true(w, val, f, sgn, exp, mnt, is_upper);
}
@safe unittest
{
// This one tests the switch between e-like and f-like output.
// There is a small gap left between the two, where the used
// variation is not clearly defined. This is intentional and due
// to the way, D handles floating point numbers. On different
// computers with different reals the results may vary in this gap.
import std.math.operations : nextDown, nextUp;
import std.math.hardware; // cannot be selective, because FloatingPointControl might not be defined
auto f = FormatSpec!dchar("");
f.spec = 'g';
double val = 999999.5;
assert(printFloat(val.nextUp, f) == "1e+06");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "999999");
val = 0.00009999995;
assert(printFloat(val.nextUp, f) == "0.0001");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "9.99999e-05");
static if (is(FloatingPointControl))
{
FloatingPointControl fpctrl;
fpctrl.rounding = FloatingPointControl.roundToZero;
val = 1000000;
assert(printFloat(val.nextUp, f) == "1e+06");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "999999");
val = 0.0001;
assert(printFloat(val.nextUp, f) == "0.0001");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "9.99999e-05");
fpctrl.rounding = FloatingPointControl.roundUp;
val = 999999;
assert(printFloat(val.nextUp, f) == "1e+06");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "999999");
// 0.0000999999 is actually represented as 0.0000999998999..., which is
// less than 0.0000999999, so we need to use nextUp to get the corner case here
val = nextUp(0.0000999999);
assert(printFloat(val.nextUp, f) == "0.0001");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "9.99999e-05");
fpctrl.rounding = FloatingPointControl.roundDown;
val = 1000000;
assert(printFloat(val.nextUp, f) == "1e+06");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "999999");
val = 0.0001;
assert(printFloat(val.nextUp, f) == "0.0001");
val = nextDown(val);
assert(printFloat(val.nextDown, f) == "9.99999e-05");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
assert(printFloat(float.nan, f) == "nan");
assert(printFloat(-float.nan, f) == "-nan");
assert(printFloat(float.infinity, f) == "inf");
assert(printFloat(-float.infinity, f) == "-inf");
assert(printFloat(0.0f, f) == "0");
assert(printFloat(-0.0f, f) == "-0");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "9.99995e-41");
assert(printFloat(cast(float) -1e-40, f) == "-9.99995e-41");
assert(printFloat(1e-30f, f) == "1e-30");
assert(printFloat(-1e-30f, f) == "-1e-30");
assert(printFloat(1e-10f, f) == "1e-10");
assert(printFloat(-1e-10f, f) == "-1e-10");
assert(printFloat(0.1f, f) == "0.1");
assert(printFloat(-0.1f, f) == "-0.1");
assert(printFloat(10.0f, f) == "10");
assert(printFloat(-10.0f, f) == "-10");
assert(printFloat(1e30f, f) == "1e+30");
assert(printFloat(-1e30f, f) == "-1e+30");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "1.4013e-45");
assert(printFloat(nextDown(-0.0f), f) == "-1.4013e-45");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
f.width = 20;
f.precision = 10;
assert(printFloat(float.nan, f) == " nan");
assert(printFloat(-float.nan, f) == " -nan");
assert(printFloat(float.infinity, f) == " inf");
assert(printFloat(-float.infinity, f) == " -inf");
assert(printFloat(0.0f, f) == " 0");
assert(printFloat(-0.0f, f) == " -0");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == " 9.999946101e-41");
assert(printFloat(cast(float) -1e-40, f) == " -9.999946101e-41");
assert(printFloat(1e-30f, f) == " 1.000000003e-30");
assert(printFloat(-1e-30f, f) == " -1.000000003e-30");
assert(printFloat(1e-10f, f) == " 1.000000013e-10");
assert(printFloat(-1e-10f, f) == " -1.000000013e-10");
assert(printFloat(0.1f, f) == " 0.1000000015");
assert(printFloat(-0.1f, f) == " -0.1000000015");
assert(printFloat(10.0f, f) == " 10");
assert(printFloat(-10.0f, f) == " -10");
assert(printFloat(1e30f, f) == " 1.000000015e+30");
assert(printFloat(-1e30f, f) == " -1.000000015e+30");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == " 1.401298464e-45");
assert(printFloat(nextDown(-0.0f), f) == " -1.401298464e-45");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
f.width = 20;
f.precision = 10;
f.flDash = true;
assert(printFloat(float.nan, f) == "nan ");
assert(printFloat(-float.nan, f) == "-nan ");
assert(printFloat(float.infinity, f) == "inf ");
assert(printFloat(-float.infinity, f) == "-inf ");
assert(printFloat(0.0f, f) == "0 ");
assert(printFloat(-0.0f, f) == "-0 ");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "9.999946101e-41 ");
assert(printFloat(cast(float) -1e-40, f) == "-9.999946101e-41 ");
assert(printFloat(1e-30f, f) == "1.000000003e-30 ");
assert(printFloat(-1e-30f, f) == "-1.000000003e-30 ");
assert(printFloat(1e-10f, f) == "1.000000013e-10 ");
assert(printFloat(-1e-10f, f) == "-1.000000013e-10 ");
assert(printFloat(0.1f, f) == "0.1000000015 ");
assert(printFloat(-0.1f, f) == "-0.1000000015 ");
assert(printFloat(10.0f, f) == "10 ");
assert(printFloat(-10.0f, f) == "-10 ");
assert(printFloat(1e30f, f) == "1.000000015e+30 ");
assert(printFloat(-1e30f, f) == "-1.000000015e+30 ");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "1.401298464e-45 ");
assert(printFloat(nextDown(-0.0f), f) == "-1.401298464e-45 ");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
f.width = 20;
f.precision = 10;
f.flZero = true;
assert(printFloat(float.nan, f) == " nan");
assert(printFloat(-float.nan, f) == " -nan");
assert(printFloat(float.infinity, f) == " inf");
assert(printFloat(-float.infinity, f) == " -inf");
assert(printFloat(0.0f, f) == "00000000000000000000");
assert(printFloat(-0.0f, f) == "-0000000000000000000");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "000009.999946101e-41");
assert(printFloat(cast(float) -1e-40, f) == "-00009.999946101e-41");
assert(printFloat(1e-30f, f) == "000001.000000003e-30");
assert(printFloat(-1e-30f, f) == "-00001.000000003e-30");
assert(printFloat(1e-10f, f) == "000001.000000013e-10");
assert(printFloat(-1e-10f, f) == "-00001.000000013e-10");
assert(printFloat(0.1f, f) == "000000000.1000000015");
assert(printFloat(-0.1f, f) == "-00000000.1000000015");
assert(printFloat(10.0f, f) == "00000000000000000010");
assert(printFloat(-10.0f, f) == "-0000000000000000010");
assert(printFloat(1e30f, f) == "000001.000000015e+30");
assert(printFloat(-1e30f, f) == "-00001.000000015e+30");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "000001.401298464e-45");
assert(printFloat(nextDown(-0.0f), f) == "-00001.401298464e-45");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
f.precision = 10;
f.flHash = true;
assert(printFloat(float.nan, f) == "nan");
assert(printFloat(-float.nan, f) == "-nan");
assert(printFloat(float.infinity, f) == "inf");
assert(printFloat(-float.infinity, f) == "-inf");
assert(printFloat(0.0f, f) == "0.000000000");
assert(printFloat(-0.0f, f) == "-0.000000000");
// cast needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(cast(float) 1e-40, f) == "9.999946101e-41");
assert(printFloat(cast(float) -1e-40, f) == "-9.999946101e-41");
assert(printFloat(1e-30f, f) == "1.000000003e-30");
assert(printFloat(-1e-30f, f) == "-1.000000003e-30");
assert(printFloat(1e-10f, f) == "1.000000013e-10");
assert(printFloat(-1e-10f, f) == "-1.000000013e-10");
assert(printFloat(0.1f, f) == "0.1000000015");
assert(printFloat(-0.1f, f) == "-0.1000000015");
assert(printFloat(10.0f, f) == "10.00000000");
assert(printFloat(-10.0f, f) == "-10.00000000");
assert(printFloat(1e30f, f) == "1.000000015e+30");
assert(printFloat(-1e30f, f) == "-1.000000015e+30");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0f), f) == "1.401298464e-45");
assert(printFloat(nextDown(-0.0f), f) == "-1.401298464e-45");
}
@safe unittest
{
import std.math.hardware; // cannot be selective, because FloatingPointControl might not be defined
// std.math's FloatingPointControl isn't available on all target platforms
static if (is(FloatingPointControl))
{
FloatingPointControl fpctrl;
char[256] buf;
auto f = FormatSpec!dchar("");
f.spec = 'g';
f.precision = 2;
fpctrl.rounding = FloatingPointControl.roundToNearest;
/*
assert(printFloat(11.5f, f, RoundingMode.toNearestTiesAwayFromZero) == "12");
assert(printFloat(12.5f, f, RoundingMode.toNearestTiesAwayFromZero) == "13");
assert(printFloat(11.7f, f, RoundingMode.toNearestTiesAwayFromZero) == "12");
assert(printFloat(11.3f, f, RoundingMode.toNearestTiesAwayFromZero) == "11");
assert(printFloat(11.0f, f, RoundingMode.toNearestTiesAwayFromZero) == "11");
assert(printFloat(-11.5f, f, RoundingMode.toNearestTiesAwayFromZero) == "-12");
assert(printFloat(-12.5f, f, RoundingMode.toNearestTiesAwayFromZero) == "-13");
assert(printFloat(-11.7f, f, RoundingMode.toNearestTiesAwayFromZero) == "-12");
assert(printFloat(-11.3f, f, RoundingMode.toNearestTiesAwayFromZero) == "-11");
assert(printFloat(-11.0f, f, RoundingMode.toNearestTiesAwayFromZero) == "-11");
*/
// ties to even
assert(printFloat(11.5f, f) == "12");
assert(printFloat(12.5f, f) == "12");
assert(printFloat(11.7f, f) == "12");
assert(printFloat(11.3f, f) == "11");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-12");
assert(printFloat(-12.5f, f) == "-12");
assert(printFloat(-11.7f, f) == "-12");
assert(printFloat(-11.3f, f) == "-11");
assert(printFloat(-11.0f, f) == "-11");
fpctrl.rounding = FloatingPointControl.roundToZero;
assert(printFloat(11.5f, f) == "11");
assert(printFloat(12.5f, f) == "12");
assert(printFloat(11.7f, f) == "11");
assert(printFloat(11.3f, f) == "11");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-11");
assert(printFloat(-12.5f, f) == "-12");
assert(printFloat(-11.7f, f) == "-11");
assert(printFloat(-11.3f, f) == "-11");
assert(printFloat(-11.0f, f) == "-11");
fpctrl.rounding = FloatingPointControl.roundUp;
assert(printFloat(11.5f, f) == "12");
assert(printFloat(12.5f, f) == "13");
assert(printFloat(11.7f, f) == "12");
assert(printFloat(11.3f, f) == "12");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-11");
assert(printFloat(-12.5f, f) == "-12");
assert(printFloat(-11.7f, f) == "-11");
assert(printFloat(-11.3f, f) == "-11");
assert(printFloat(-11.0f, f) == "-11");
fpctrl.rounding = FloatingPointControl.roundDown;
assert(printFloat(11.5f, f) == "11");
assert(printFloat(12.5f, f) == "12");
assert(printFloat(11.7f, f) == "11");
assert(printFloat(11.3f, f) == "11");
assert(printFloat(11.0f, f) == "11");
assert(printFloat(-11.5f, f) == "-12");
assert(printFloat(-12.5f, f) == "-13");
assert(printFloat(-11.7f, f) == "-12");
assert(printFloat(-11.3f, f) == "-12");
assert(printFloat(-11.0f, f) == "-11");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
assert(printFloat(double.nan, f) == "nan");
assert(printFloat(-double.nan, f) == "-nan");
assert(printFloat(double.infinity, f) == "inf");
assert(printFloat(-double.infinity, f) == "-inf");
assert(printFloat(0.0, f) == "0");
assert(printFloat(-0.0, f) == "-0");
// / 1000 needed due to https://issues.dlang.org/show_bug.cgi?id=20361
assert(printFloat(1e-307 / 1000, f) == "1e-310");
assert(printFloat(-1e-307 / 1000, f) == "-1e-310");
assert(printFloat(1e-30, f) == "1e-30");
assert(printFloat(-1e-30, f) == "-1e-30");
assert(printFloat(1e-10, f) == "1e-10");
assert(printFloat(-1e-10, f) == "-1e-10");
assert(printFloat(0.1, f) == "0.1");
assert(printFloat(-0.1, f) == "-0.1");
assert(printFloat(10.0, f) == "10");
assert(printFloat(-10.0, f) == "-10");
assert(printFloat(1e300, f) == "1e+300");
assert(printFloat(-1e300, f) == "-1e+300");
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0), f) == "4.94066e-324");
assert(printFloat(nextDown(-0.0), f) == "-4.94066e-324");
}
@safe unittest
{
static if (real.mant_dig > 64)
{
pragma(msg, "printFloat tests disabled because of unsupported `real` format");
}
else
{
char[256] buf;
auto f = FormatSpec!dchar("");
f.spec = 'g';
assert(printFloat(real.nan, f) == "nan");
assert(printFloat(-real.nan, f) == "-nan");
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(-real.infinity, f) == "-inf");
}
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
import std.math.operations : nextUp;
double eps = nextUp(0.0);
f.precision = 1000;
assert(printFloat(eps, f) ==
"4.940656458412465441765687928682213723650598026143247644255856825006"
~ "755072702087518652998363616359923797965646954457177309266567103559"
~ "397963987747960107818781263007131903114045278458171678489821036887"
~ "186360569987307230500063874091535649843873124733972731696151400317"
~ "153853980741262385655911710266585566867681870395603106249319452715"
~ "914924553293054565444011274801297099995419319894090804165633245247"
~ "571478690147267801593552386115501348035264934720193790268107107491"
~ "703332226844753335720832431936092382893458368060106011506169809753"
~ "078342277318329247904982524730776375927247874656084778203734469699"
~ "533647017972677717585125660551199131504891101451037862738167250955"
~ "837389733598993664809941164205702637090279242767544565229087538682"
~ "506419718265533447265625e-324");
f.precision = 50;
assert(printFloat(double.max, f) ==
"1.7976931348623157081452742373170435679807056752584e+308");
assert(printFloat(double.epsilon, f) ==
"2.220446049250313080847263336181640625e-16");
f.precision = 10;
assert(printFloat(1.0/3.0, f) == "0.3333333333");
assert(printFloat(1.0/7.0, f) == "0.1428571429");
assert(printFloat(1.0/9.0, f) == "0.1111111111");
}
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
f.precision = 15;
import std.math.constants : E, PI, PI_2, PI_4, M_1_PI, M_2_PI, M_2_SQRTPI,
LN10, LN2, LOG2, LOG2E, LOG2T, LOG10E, SQRT2, SQRT1_2;
assert(printFloat(cast(double) E, f) == "2.71828182845905");
assert(printFloat(cast(double) PI, f) == "3.14159265358979");
assert(printFloat(cast(double) PI_2, f) == "1.5707963267949");
assert(printFloat(cast(double) PI_4, f) == "0.785398163397448");
assert(printFloat(cast(double) M_1_PI, f) == "0.318309886183791");
assert(printFloat(cast(double) M_2_PI, f) == "0.636619772367581");
assert(printFloat(cast(double) M_2_SQRTPI, f) == "1.12837916709551");
assert(printFloat(cast(double) LN10, f) == "2.30258509299405");
assert(printFloat(cast(double) LN2, f) == "0.693147180559945");
assert(printFloat(cast(double) LOG2, f) == "0.301029995663981");
assert(printFloat(cast(double) LOG2E, f) == "1.44269504088896");
assert(printFloat(cast(double) LOG2T, f) == "3.32192809488736");
assert(printFloat(cast(double) LOG10E, f) == "0.434294481903252");
assert(printFloat(cast(double) SQRT2, f) == "1.4142135623731");
assert(printFloat(cast(double) SQRT1_2, f) == "0.707106781186548");
}
// for 100% coverage
@safe unittest
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
f.precision = 0;
assert(printFloat(0.009999, f) == "0.01");
}
@safe unittest
{
static if (real.mant_dig > 64)
{
pragma(msg, "printFloat tests disabled because of unsupported `real` format");
}
else
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
assert(printFloat(real.nan, f) == "nan");
assert(printFloat(-real.nan, f) == "-nan");
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(-real.infinity, f) == "-inf");
assert(printFloat(0.0L, f) == "0");
assert(printFloat(-0.0L, f) == "-0");
}
static if (real.mant_dig == 64)
{
assert(printFloat(1e-4940L, f) == "1e-4940");
assert(printFloat(-1e-4940L, f) == "-1e-4940");
assert(printFloat(1e-30L, f) == "1e-30");
assert(printFloat(-1e-30L, f) == "-1e-30");
assert(printFloat(1e-10L, f) == "1e-10");
assert(printFloat(-1e-10L, f) == "-1e-10");
assert(printFloat(0.1L, f) == "0.1");
assert(printFloat(-0.1L, f) == "-0.1");
assert(printFloat(10.0L, f) == "10");
assert(printFloat(-10.0L, f) == "-10");
version (Windows) {} // issue 20972
else
{
assert(printFloat(1e4000L, f) == "1e+4000");
assert(printFloat(-1e4000L, f) == "-1e+4000");
}
import std.math.operations : nextUp, nextDown;
assert(printFloat(nextUp(0.0L), f) == "3.6452e-4951");
assert(printFloat(nextDown(-0.0L), f) == "-3.6452e-4951");
}
}
@safe unittest
{
import std.exception : assertCTFEable;
import std.math.exponential : log2;
import std.math.operations : nextDown;
assertCTFEable!(
{
// log2 is broken for x87-reals on some computers in CTFE
// the following tests excludes these computers from the tests
// (issue 21757)
enum test = cast(int) log2(3.05e2312L);
static if (real.mant_dig == 64 && test == 7681)
{
auto f = FormatSpec!dchar("");
f.spec = 'g';
assert(printFloat(real.infinity, f) == "inf");
assert(printFloat(10.0L, f) == "10");
assert(printFloat(2.6080L, f) == "2.608");
assert(printFloat(3.05e2312L, f) == "3.05e+2312");
f.precision = 60;
assert(printFloat(2.65e-54L, f) ==
"2.65000000000000000005900998740054701394102894093529654759941e-54");
/*
commented out, because CTFE is currently too slow for 5000 digits with extreme values
f.precision = 5000;
auto result2 = printFloat(1.2119e-4822L, f);
assert(result2.length == 5007);
assert(result2[$ - 20 .. $] == "26072948659534e-4822");
auto result3 = printFloat(real.min_normal, f);
assert(result3.length == 5007);
assert(result3[$ - 20 .. $] == "72078141008227e-4932");
auto result4 = printFloat(real.min_normal.nextDown, f);
assert(result4.length == 5007);
assert(result4[$ - 20 .. $] == "48141326333101e-4932");
*/
}
});
}
// check no allocations
@safe unittest
{
import std.format : NoOpSink;
auto w = NoOpSink();
import core.memory;
auto stats = () @trusted { return GC.stats; } ();
auto f = FormatSpec!dchar("");
f.spec = 'a';
printFloat(w, float.nan, f);
printFloat(w, -float.infinity, f);
printFloat(w, 0.0f, f);
printFloat(w, -double.nan, f);
printFloat(w, double.infinity, f);
printFloat(w, -0.0, f);
import std.math.operations : nextUp;
import std.math.constants : E;
printFloat(w, nextUp(0.0f), f);
printFloat(w, cast(float) E, f);
f.precision = 1000;
printFloat(w, float.nan, f);
printFloat(w, 0.0, f);
printFloat(w, 1.23456789e+100, f);
f.spec = 'E';
f.precision = 80;
printFloat(w, 5.62776e+12f, f);
f.precision = 6;
printFloat(w, -1.1418613e+07f, f);
f.precision = 20;
printFloat(w, double.max, f);
printFloat(w, nextUp(0.0), f);
f.precision = 1000;
printFloat(w, 1.0, f);
f.spec = 'f';
f.precision = 15;
printFloat(w, cast(double) E, f);
f.precision = 20;
printFloat(w, double.max, f);
printFloat(w, nextUp(0.0), f);
f.precision = 1000;
printFloat(w, 1.0, f);
f.spec = 'g';
f.precision = 15;
printFloat(w, cast(double) E, f);
f.precision = 20;
printFloat(w, double.max, f);
printFloat(w, nextUp(0.0), f);
f.flHash = true;
f.precision = 1000;
printFloat(w, 1.0, f);
assert(() @trusted { return GC.stats.usedSize; } () == stats.usedSize);
}