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// Copyright 2015 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 big
import (
"fmt"
"testing"
)
func TestDecimalString(t *testing.T) {
for _, test := range []struct {
x decimal
want string
}{
{want: "0"},
{decimal{nil, 1000}, "0"}, // exponent of 0 is ignored
{decimal{[]byte("12345"), 0}, "0.12345"},
{decimal{[]byte("12345"), -3}, "0.00012345"},
{decimal{[]byte("12345"), +3}, "123.45"},
{decimal{[]byte("12345"), +10}, "1234500000"},
} {
if got := test.x.String(); got != test.want {
t.Errorf("%v == %s; want %s", test.x, got, test.want)
}
}
}
func TestDecimalInit(t *testing.T) {
for _, test := range []struct {
x Word
shift int
want string
}{
{0, 0, "0"},
{0, -100, "0"},
{0, 100, "0"},
{1, 0, "1"},
{1, 10, "1024"},
{1, 100, "1267650600228229401496703205376"},
{1, -100, "0.0000000000000000000000000000007888609052210118054117285652827862296732064351090230047702789306640625"},
{12345678, 8, "3160493568"},
{12345678, -8, "48225.3046875"},
{195312, 9, "99999744"},
{1953125, 9, "1000000000"},
} {
var d decimal
d.init(nat{test.x}.norm(), test.shift)
if got := d.String(); got != test.want {
t.Errorf("%d << %d == %s; want %s", test.x, test.shift, got, test.want)
}
}
}
func TestDecimalRounding(t *testing.T) {
for _, test := range []struct {
x uint64
n int
down, even, up string
}{
{0, 0, "0", "0", "0"},
{0, 1, "0", "0", "0"},
{1, 0, "0", "0", "10"},
{5, 0, "0", "0", "10"},
{9, 0, "0", "10", "10"},
{15, 1, "10", "20", "20"},
{45, 1, "40", "40", "50"},
{95, 1, "90", "100", "100"},
{12344999, 4, "12340000", "12340000", "12350000"},
{12345000, 4, "12340000", "12340000", "12350000"},
{12345001, 4, "12340000", "12350000", "12350000"},
{23454999, 4, "23450000", "23450000", "23460000"},
{23455000, 4, "23450000", "23460000", "23460000"},
{23455001, 4, "23450000", "23460000", "23460000"},
{99994999, 4, "99990000", "99990000", "100000000"},
{99995000, 4, "99990000", "100000000", "100000000"},
{99999999, 4, "99990000", "100000000", "100000000"},
{12994999, 4, "12990000", "12990000", "13000000"},
{12995000, 4, "12990000", "13000000", "13000000"},
{12999999, 4, "12990000", "13000000", "13000000"},
} {
x := nat(nil).setUint64(test.x)
var d decimal
d.init(x, 0)
d.roundDown(test.n)
if got := d.String(); got != test.down {
t.Errorf("roundDown(%d, %d) = %s; want %s", test.x, test.n, got, test.down)
}
d.init(x, 0)
d.round(test.n)
if got := d.String(); got != test.even {
t.Errorf("round(%d, %d) = %s; want %s", test.x, test.n, got, test.even)
}
d.init(x, 0)
d.roundUp(test.n)
if got := d.String(); got != test.up {
t.Errorf("roundUp(%d, %d) = %s; want %s", test.x, test.n, got, test.up)
}
}
}
var sink string
func BenchmarkDecimalConversion(b *testing.B) {
for i := 0; i < b.N; i++ {
for shift := -100; shift <= +100; shift++ {
var d decimal
d.init(natOne, shift)
sink = d.String()
}
}
}
func BenchmarkFloatString(b *testing.B) {
x := new(Float)
for _, prec := range []uint{1e2, 1e3, 1e4, 1e5} {
x.SetPrec(prec).SetRat(NewRat(1, 3))
b.Run(fmt.Sprintf("%v", prec), func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
sink = x.String()
}
})
}
}