// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package strconv_test
import (
"math"
"math/rand"
. "strconv"
"testing"
)
type ftoaTest struct {
f float64
fmt byte
prec int
s string
}
func fdiv(a, b float64) float64 { return a / b } // keep compiler in the dark
const (
below1e23 = 99999999999999974834176
above1e23 = 100000000000000008388608
)
var ftoatests = []ftoaTest{
{1, 'e', 5, "1.00000e+00"},
{1, 'f', 5, "1.00000"},
{1, 'g', 5, "1"},
{1, 'g', -1, "1"},
{20, 'g', -1, "20"},
{1234567.8, 'g', -1, "1.2345678e+06"},
{200000, 'g', -1, "200000"},
{2000000, 'g', -1, "2e+06"},
// g conversion and zero suppression
{400, 'g', 2, "4e+02"},
{40, 'g', 2, "40"},
{4, 'g', 2, "4"},
{.4, 'g', 2, "0.4"},
{.04, 'g', 2, "0.04"},
{.004, 'g', 2, "0.004"},
{.0004, 'g', 2, "0.0004"},
{.00004, 'g', 2, "4e-05"},
{.000004, 'g', 2, "4e-06"},
{0, 'e', 5, "0.00000e+00"},
{0, 'f', 5, "0.00000"},
{0, 'g', 5, "0"},
{0, 'g', -1, "0"},
{-1, 'e', 5, "-1.00000e+00"},
{-1, 'f', 5, "-1.00000"},
{-1, 'g', 5, "-1"},
{-1, 'g', -1, "-1"},
{12, 'e', 5, "1.20000e+01"},
{12, 'f', 5, "12.00000"},
{12, 'g', 5, "12"},
{12, 'g', -1, "12"},
{123456700, 'e', 5, "1.23457e+08"},
{123456700, 'f', 5, "123456700.00000"},
{123456700, 'g', 5, "1.2346e+08"},
{123456700, 'g', -1, "1.234567e+08"},
{1.2345e6, 'e', 5, "1.23450e+06"},
{1.2345e6, 'f', 5, "1234500.00000"},
{1.2345e6, 'g', 5, "1.2345e+06"},
{1e23, 'e', 17, "9.99999999999999916e+22"},
{1e23, 'f', 17, "99999999999999991611392.00000000000000000"},
{1e23, 'g', 17, "9.9999999999999992e+22"},
{1e23, 'e', -1, "1e+23"},
{1e23, 'f', -1, "100000000000000000000000"},
{1e23, 'g', -1, "1e+23"},
{below1e23, 'e', 17, "9.99999999999999748e+22"},
{below1e23, 'f', 17, "99999999999999974834176.00000000000000000"},
{below1e23, 'g', 17, "9.9999999999999975e+22"},
{below1e23, 'e', -1, "9.999999999999997e+22"},
{below1e23, 'f', -1, "99999999999999970000000"},
{below1e23, 'g', -1, "9.999999999999997e+22"},
{above1e23, 'e', 17, "1.00000000000000008e+23"},
{above1e23, 'f', 17, "100000000000000008388608.00000000000000000"},
{above1e23, 'g', 17, "1.0000000000000001e+23"},
{above1e23, 'e', -1, "1.0000000000000001e+23"},
{above1e23, 'f', -1, "100000000000000010000000"},
{above1e23, 'g', -1, "1.0000000000000001e+23"},
{fdiv(5e-304, 1e20), 'g', -1, "5e-324"},
{fdiv(-5e-304, 1e20), 'g', -1, "-5e-324"},
{32, 'g', -1, "32"},
{32, 'g', 0, "3e+01"},
{100, 'x', -1, "%x"},
{math.NaN(), 'g', -1, "NaN"},
{-math.NaN(), 'g', -1, "NaN"},
{math.Inf(0), 'g', -1, "+Inf"},
{math.Inf(-1), 'g', -1, "-Inf"},
{-math.Inf(0), 'g', -1, "-Inf"},
{-1, 'b', -1, "-4503599627370496p-52"},
// fixed bugs
{0.9, 'f', 1, "0.9"},
{0.09, 'f', 1, "0.1"},
{0.0999, 'f', 1, "0.1"},
{0.05, 'f', 1, "0.1"},
{0.05, 'f', 0, "0"},
{0.5, 'f', 1, "0.5"},
{0.5, 'f', 0, "0"},
{1.5, 'f', 0, "2"},
// http://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/
{2.2250738585072012e-308, 'g', -1, "2.2250738585072014e-308"},
// http://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/
{2.2250738585072011e-308, 'g', -1, "2.225073858507201e-308"},
// Issue 2625.
{383260575764816448, 'f', 0, "383260575764816448"},
{383260575764816448, 'g', -1, "3.8326057576481645e+17"},
}
func TestFtoa(t *testing.T) {
for i := 0; i < len(ftoatests); i++ {
test := &ftoatests[i]
s := FormatFloat(test.f, test.fmt, test.prec, 64)
if s != test.s {
t.Error("testN=64", test.f, string(test.fmt), test.prec, "want", test.s, "got", s)
}
x := AppendFloat([]byte("abc"), test.f, test.fmt, test.prec, 64)
if string(x) != "abc"+test.s {
t.Error("AppendFloat testN=64", test.f, string(test.fmt), test.prec, "want", "abc"+test.s, "got", string(x))
}
if float64(float32(test.f)) == test.f && test.fmt != 'b' {
s := FormatFloat(test.f, test.fmt, test.prec, 32)
if s != test.s {
t.Error("testN=32", test.f, string(test.fmt), test.prec, "want", test.s, "got", s)
}
x := AppendFloat([]byte("abc"), test.f, test.fmt, test.prec, 32)
if string(x) != "abc"+test.s {
t.Error("AppendFloat testN=32", test.f, string(test.fmt), test.prec, "want", "abc"+test.s, "got", string(x))
}
}
}
}
func TestFtoaRandom(t *testing.T) {
N := int(1e4)
if testing.Short() {
N = 100
}
t.Logf("testing %d random numbers with fast and slow FormatFloat", N)
for i := 0; i < N; i++ {
bits := uint64(rand.Uint32())<<32 | uint64(rand.Uint32())
x := math.Float64frombits(bits)
shortFast := FormatFloat(x, 'g', -1, 64)
SetOptimize(false)
shortSlow := FormatFloat(x, 'g', -1, 64)
SetOptimize(true)
if shortSlow != shortFast {
t.Errorf("%b printed as %s, want %s", x, shortFast, shortSlow)
}
prec := rand.Intn(12) + 5
shortFast = FormatFloat(x, 'e', prec, 64)
SetOptimize(false)
shortSlow = FormatFloat(x, 'e', prec, 64)
SetOptimize(true)
if shortSlow != shortFast {
t.Errorf("%b printed as %s, want %s", x, shortFast, shortSlow)
}
}
}
func BenchmarkFormatFloatDecimal(b *testing.B) {
for i := 0; i < b.N; i++ {
FormatFloat(33909, 'g', -1, 64)
}
}
func BenchmarkFormatFloat(b *testing.B) {
for i := 0; i < b.N; i++ {
FormatFloat(339.7784, 'g', -1, 64)
}
}
func BenchmarkFormatFloatExp(b *testing.B) {
for i := 0; i < b.N; i++ {
FormatFloat(-5.09e75, 'g', -1, 64)
}
}
func BenchmarkFormatFloatNegExp(b *testing.B) {
for i := 0; i < b.N; i++ {
FormatFloat(-5.11e-95, 'g', -1, 64)
}
}
func BenchmarkFormatFloatBig(b *testing.B) {
for i := 0; i < b.N; i++ {
FormatFloat(123456789123456789123456789, 'g', -1, 64)
}
}
func benchmarkAppendFloat(b *testing.B, f float64, fmt byte, prec, bitSize int) {
dst := make([]byte, 30)
for i := 0; i < b.N; i++ {
AppendFloat(dst[:0], f, fmt, prec, bitSize)
}
}
func BenchmarkAppendFloatDecimal(b *testing.B) { benchmarkAppendFloat(b, 33909, 'g', -1, 64) }
func BenchmarkAppendFloat(b *testing.B) { benchmarkAppendFloat(b, 339.7784, 'g', -1, 64) }
func BenchmarkAppendFloatExp(b *testing.B) { benchmarkAppendFloat(b, -5.09e75, 'g', -1, 64) }
func BenchmarkAppendFloatNegExp(b *testing.B) { benchmarkAppendFloat(b, -5.11e-95, 'g', -1, 64) }
func BenchmarkAppendFloatBig(b *testing.B) {
benchmarkAppendFloat(b, 123456789123456789123456789, 'g', -1, 64)
}
func BenchmarkAppendFloatBinaryExp(b *testing.B) { benchmarkAppendFloat(b, -1, 'b', -1, 64) }
func BenchmarkAppendFloat32Integer(b *testing.B) { benchmarkAppendFloat(b, 33909, 'g', -1, 32) }
func BenchmarkAppendFloat32ExactFraction(b *testing.B) { benchmarkAppendFloat(b, 3.375, 'g', -1, 32) }
func BenchmarkAppendFloat32Point(b *testing.B) { benchmarkAppendFloat(b, 339.7784, 'g', -1, 32) }
func BenchmarkAppendFloat32Exp(b *testing.B) { benchmarkAppendFloat(b, -5.09e25, 'g', -1, 32) }
func BenchmarkAppendFloat32NegExp(b *testing.B) { benchmarkAppendFloat(b, -5.11e-25, 'g', -1, 32) }
func BenchmarkAppendFloat64Fixed1(b *testing.B) { benchmarkAppendFloat(b, 123456, 'e', 3, 64) }
func BenchmarkAppendFloat64Fixed2(b *testing.B) { benchmarkAppendFloat(b, 123.456, 'e', 3, 64) }
func BenchmarkAppendFloat64Fixed3(b *testing.B) { benchmarkAppendFloat(b, 1.23456e+78, 'e', 3, 64) }
func BenchmarkAppendFloat64Fixed4(b *testing.B) { benchmarkAppendFloat(b, 1.23456e-78, 'e', 3, 64) }