- update

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 李光春
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,36 @@
+<h1>
+<a href="https://www.dtapp.net/">Golang Decimal</a>
+</h1>
+
+📦 Golang 小数点处理
+
+[comment]: <> (go)
+[![godoc](https://pkg.go.dev/badge/go.dtapp.net/godecimal?status.svg)](https://pkg.go.dev/go.dtapp.net/godecimal)
+[![goproxy.cn](https://goproxy.cn/stats/go.dtapp.net/godecimal/badges/download-count.svg)](https://goproxy.cn/stats/go.dtapp.net/godecimal)
+[![goreportcard.com](https://goreportcard.com/badge/go.dtapp.net/godecimal)](https://goreportcard.com/report/go.dtapp.net/godecimal)
+[![deps.dev](https://img.shields.io/badge/deps-go-red.svg)](https://deps.dev/go/go.dtapp.net%2Fgodecimal)
+
+#### 安装
+
+```go
+go get -v -u go.dtapp.net/godecimal
+```
+
+#### 使用
+
+```go
+package main
+
+import (
+	"go.dtapp.net/godecimal"
+	"log"
+	"reflect"
+)
+
+func main() {
+	log.Println("加：", godecimal.Float64Add(10, 3), reflect.TypeOf(godecimal.Float64Add(10, 3)))
+	log.Println("减", godecimal.Float64Sub(10, 3), reflect.TypeOf(godecimal.Float64Sub(10, 3)))
+	log.Println("乘：", godecimal.Float64Mul(10, 3), reflect.TypeOf(godecimal.Float64Mul(10, 3)))
+	log.Println("除：", godecimal.Float64Quo(10, 3), reflect.TypeOf(godecimal.Float64Quo(10, 3)))
+}
+```

big.go

@@ -0,0 +1,15 @@
+package godecimal
+
+import (
+	"math/big"
+)
+
+type Decimal struct {
+	floatValue *big.Float
+}
+
+func New() Decimal {
+	return Decimal{
+		floatValue: new(big.Float),
+	}
+}

big_new.go

@@ -0,0 +1,29 @@
+package godecimal
+
+// NewString 从字符串创建
+func NewString(s string) Decimal {
+	d := New()
+	d.floatValue.SetString(s)
+	return d
+}
+
+// NewFloat 从浮点数创建
+func NewFloat(f float64) Decimal {
+	d := New()
+	d.floatValue.SetFloat64(f)
+	return d
+}
+
+// NewInt 从整数创建
+func NewInt(i int64) Decimal {
+	d := New()
+	d.floatValue.SetInt64(i)
+	return d
+}
+
+// NewUint 从无符合整数创建
+func NewUint(i uint64) Decimal {
+	d := New()
+	d.floatValue.SetUint64(i)
+	return d
+}

big_operation.go

@@ -0,0 +1,29 @@
+package godecimal
+
+// Add 加 (d+d2)
+func (d Decimal) Add(d2 Decimal) Decimal {
+	mul := New()
+	mul.floatValue.Add(d.floatValue, d2.floatValue)
+	return mul
+}
+
+// Sub 减 (d-d2)
+func (d Decimal) Sub(d2 Decimal) Decimal {
+	mul := New()
+	mul.floatValue.Sub(d.floatValue, d2.floatValue)
+	return mul
+}
+
+// Mul 乘 (d*d2)
+func (d Decimal) Mul(d2 Decimal) Decimal {
+	mul := New()
+	mul.floatValue.Mul(d.floatValue, d2.floatValue)
+	return mul
+}
+
+// Quo 除 (d/d2)
+func (d Decimal) Quo(d2 Decimal) Decimal {
+	mul := New()
+	mul.floatValue.Quo(d.floatValue, d2.floatValue)
+	return mul
+}

big_output.go

@@ -0,0 +1,24 @@
+package godecimal
+
+import (
+	"math/big"
+)
+
+// String 输出 string
+func (d Decimal) String() string {
+	return d.floatValue.String()
+}
+
+// Float64 输出 float64
+func (d Decimal) Float64() float64 {
+	rat, _ := new(big.Rat).SetString(d.String())
+	f, _ := rat.Float64()
+	return f
+}
+
+// MoneyFloat64 货币 float64
+func (d Decimal) MoneyFloat64() float64 {
+	rat, _ := new(big.Rat).SetString(d.floatValue.Text('f', 2))
+	f, _ := rat.Float64()
+	return f
+}

big_test.go

@@ -0,0 +1,97 @@
+package godecimal
+
+import (
+	"fmt"
+	"github.com/shopspring/decimal"
+	"math/big"
+	"reflect"
+	"testing"
+)
+
+func TestNew(t *testing.T) {
+
+	priceString := NewString("100")
+	t.Log("从字符串创建：", priceString)
+
+	priceFloat := NewFloat(0.20)
+	t.Log("从浮点数创建：", priceFloat)
+
+	priceInt := NewInt(300)
+	t.Log("从整数创建：", priceInt)
+
+	priceUint := NewUint(400)
+	t.Log("从无符合整数创建：", priceUint)
+
+	t.Log("加：", priceString.Add(priceFloat), reflect.TypeOf(priceString))
+	t.Log("减", priceString.Sub(priceFloat), reflect.TypeOf(priceString))
+	t.Log("乘：", priceString.Mul(priceFloat), reflect.TypeOf(priceString))
+	t.Log("除：", priceString.Quo(priceFloat), reflect.TypeOf(priceString))
+}
+
+// https://www.itranslater.com/qa/details/2582643503239005184
+// https://stackoverflow.com/questions/18390266/how-can-we-truncate-float64-type-to-a-particular-precision
+func TestOperation(t *testing.T) {
+
+	a1 := NewFloat(0.1890)
+	t.Log("a1：", a1)
+
+	a2 := NewFloat(0.50)
+	t.Log("a2：", a2)
+
+	t.Log("a1+a2：", a1.Add(a2), a1.Add(a2).String(), a1.Add(a2).Float64(), reflect.TypeOf(a1.Add(a2).Float64()), a1.Add(a2).MoneyFloat64(), reflect.TypeOf(a1.Add(a2).MoneyFloat64()))
+	t.Log("a1-a2：", a1.Sub(a2), a1.Sub(a2).String(), a1.Sub(a2).Float64(), reflect.TypeOf(a1.Sub(a2).Float64()), a1.Sub(a2).MoneyFloat64(), reflect.TypeOf(a1.Sub(a2).MoneyFloat64()))
+	t.Log("a1*a2：", a1.Mul(a2), a1.Mul(a2).String(), a1.Mul(a2).Float64(), reflect.TypeOf(a1.Mul(a2).Float64()), a1.Mul(a2).MoneyFloat64(), reflect.TypeOf(a1.Mul(a2).MoneyFloat64()))
+	t.Log("a1/a2：", a1.Quo(a2), a1.Quo(a2).String(), a1.Quo(a2).Float64(), reflect.TypeOf(a1.Quo(a2).Float64()), a1.Quo(a2).MoneyFloat64(), reflect.TypeOf(a1.Quo(a2).MoneyFloat64()))
+
+	a3 := NewFloat(.035)
+	t.Log("a3：", a3)
+
+	a4 := NewFloat(.08875)
+	t.Log("a4：", a4)
+
+	t.Log("a3+a4：", a3.Add(a4), a3.Add(a4).String(), a3.Add(a4).Float64(), reflect.TypeOf(a3.Add(a4).Float64()), a3.Add(a4).MoneyFloat64(), reflect.TypeOf(a3.Add(a4).MoneyFloat64()))
+	t.Log("a3-a4：", a3.Sub(a4), a3.Sub(a4).String(), a3.Sub(a4).Float64(), reflect.TypeOf(a3.Sub(a4).Float64()), a3.Sub(a4).MoneyFloat64(), reflect.TypeOf(a3.Sub(a4).MoneyFloat64()))
+	t.Log("a3*a4：", a3.Mul(a4), a3.Mul(a4).String(), a3.Mul(a4).Float64(), reflect.TypeOf(a3.Mul(a4).Float64()), a3.Mul(a4).MoneyFloat64(), reflect.TypeOf(a3.Mul(a4).MoneyFloat64()))
+	t.Log("a3/a4：", a3.Quo(a4), a3.Quo(a4).String(), a3.Quo(a4).Float64(), reflect.TypeOf(a3.Quo(a4).Float64()), a3.Quo(a4).MoneyFloat64(), reflect.TypeOf(a3.Quo(a4).MoneyFloat64()))
+}
+
+func TestDecimal1(t *testing.T) {
+	price, err := decimal.NewFromString("136.02")
+	if err != nil {
+		panic(err)
+	}
+
+	quantity := decimal.NewFromInt(3)
+
+	fee, _ := decimal.NewFromString(".035")
+	taxRate, _ := decimal.NewFromString(".08875")
+
+	subtotal := price.Mul(quantity)
+
+	preTax := subtotal.Mul(fee.Add(decimal.NewFromFloat(1)))
+
+	total := preTax.Mul(taxRate.Add(decimal.NewFromFloat(1)))
+
+	fmt.Println("Subtotal:", subtotal, reflect.TypeOf(subtotal)) // Subtotal: 408.06
+	fmt.Println("Pre-tax:", preTax, reflect.TypeOf(preTax))      // Pre-tax: 422.3421
+	fmt.Println("Taxes:", total.Sub(preTax))                     // Taxes: 37.482861375
+	fmt.Println("Total:", total)                                 // Total: 459.824961375
+	fmt.Println("Tax rate:", total.Sub(preTax).Div(preTax))      // Tax rate: 0.08875
+
+	t.Log(total.String())
+	t.Log(total.Float64())
+	t.Log(total.Floor())
+
+}
+
+func Test3(t *testing.T) {
+
+	var x1, y1 float64 = 10, 3
+	z1 := x1 / y1
+	t.Log(x1, y1, z1)
+
+	x2, y2 := big.NewFloat(10), big.NewFloat(3)
+	z2 := new(big.Float).Quo(x2, y2)
+	t.Log(x2, y2, z2)
+
+}

calculate.go

@@ -0,0 +1,21 @@
+package godecimal
+
+// Float64Add 加 (f1+f2)
+func Float64Add(f1, f2 float64) float64 {
+	return NewFloat(f1).Add(NewFloat(f2)).Float64()
+}
+
+// Float64Sub 减 (f1-f2)
+func Float64Sub(f1, f2 float64) float64 {
+	return NewFloat(f1).Sub(NewFloat(f2)).Float64()
+}
+
+// Float64Mul 乘 (f1*f2)
+func Float64Mul(f1, f2 float64) float64 {
+	return NewFloat(f1).Mul(NewFloat(f2)).Float64()
+}
+
+// Float64Quo 除 (f1/f2)
+func Float64Quo(f1, f2 float64) float64 {
+	return NewFloat(f1).Quo(NewFloat(f2)).Float64()
+}

calculate_test.go

@@ -0,0 +1,13 @@
+package godecimal
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestCalculation(t *testing.T) {
+	t.Log("加：", Float64Add(10, 3), reflect.TypeOf(Float64Add(10, 3)))
+	t.Log("减", Float64Sub(10, 3), reflect.TypeOf(Float64Sub(10, 3)))
+	t.Log("乘：", Float64Mul(10, 3), reflect.TypeOf(Float64Mul(10, 3)))
+	t.Log("除：", Float64Quo(10, 3), reflect.TypeOf(Float64Quo(10, 3)))
+}

go.mod

@@ -2,4 +2,4 @@ module go.dtapp.net/godecimal
 
 go 1.18
 
-require go.dtapp.net/gostring v1.0.3
+require github.com/shopspring/decimal v1.3.1

go.sum

@@ -1,2 +1,2 @@
-go.dtapp.net/gostring v1.0.3 h1:KSOq4D77/g5yZN/bqWfZ0kOOaPr/P1240vg03+XdENI=
-go.dtapp.net/gostring v1.0.3/go.mod h1:+ggrOvgQDQturi1QGsXEpyRN/ZPoRDaqhMujIk5lrgQ=
+github.com/shopspring/decimal v1.3.1 h1:2Usl1nmF/WZucqkFZhnfFYxxxu8LG21F6nPQBE5gKV8=
+github.com/shopspring/decimal v1.3.1/go.mod h1:DKyhrW/HYNuLGql+MJL6WCR6knT2jwCFRcu2hWCYk4o=

godecimal.go

@@ -1,115 +0,0 @@
-package godecimal
-
-import (
-	"fmt"
-	"go.dtapp.net/gostring"
-	"math"
-	"strconv"
-)
-
-// Decimal 四舍五入
-func Decimal(value float64) float64 {
-	value, _ = strconv.ParseFloat(fmt.Sprintf("%.2f", value), 64)
-	return value
-}
-
-// Round 四舍五入
-func Round(f float64, n int) float64 {
-	n10 := math.Pow10(n)
-	return math.Trunc((f+0.5/n10)*n10) / n10
-}
-
-// RoundYInt64 四舍五入
-func RoundYInt64(y int64, n int) float64 {
-	return Round(float64(y/100), n)
-}
-
-// RoundYString 四舍五入
-func RoundYString(y string, n int) float64 {
-	return Round(gostring.ToFloat64(y)/100, n)
-}
-
-// Multiply 相乘
-func Multiply(y, x float64) float64 {
-	return Round(y*x, 2)
-}
-
-// PddCouponAmount 优惠券金额
-func PddCouponAmount(y int64) float64 {
-	return Round(float64(y)/100, 2)
-}
-
-// PddCouponProportion 拼多多佣金比率
-func PddCouponProportion(y int64) float64 {
-	return Round(float64(y)/10, 2)
-}
-
-// PddGoodsOriginalPrice 拼多多商品原价
-func PddGoodsOriginalPrice(y int64) float64 {
-	return Round(float64(y)/100, 2)
-}
-
-// PddGoodsPrice 拼多多商品券后价
-func PddGoodsPrice(y, x float64) float64 {
-	return Round(y-x, 2)
-}
-
-// PddCommission 拼多多佣金
-func PddCommission(y, x float64) float64 {
-	return Round((y*x)/100, 2)
-}
-
-// TbCouponAmount 淘宝优惠券金额
-func TbCouponAmount(y int64) float64 {
-	return Round(float64(y), 2)
-}
-
-// TbCouponProportion 淘宝佣金比率
-func TbCouponProportion(y string) float64 {
-	return Round(gostring.ToFloat64(y)/100, 2)
-}
-
-// TbGoodsOriginalPrice 淘宝商品原价
-func TbGoodsOriginalPrice(y string) float64 {
-	return Round(gostring.ToFloat64(y), 2)
-}
-
-// TbGoodsPrice 淘宝商品券后价
-func TbGoodsPrice(y, x float64) float64 {
-	return Round(y-x, 2)
-}
-
-// TbCommission 淘宝佣金
-func TbCommission(y, x float64) float64 {
-	return Round((y*x)/100, 2)
-}
-
-// WmCouponAmount 小商店优惠券金额
-func WmCouponAmount(y string) float64 {
-	return Round(gostring.ToFloat64(y)/100, 2)
-}
-
-// WmCouponProportion 小商店佣金比率
-func WmCouponProportion(y int64) float64 {
-	return Round(float64(y)/100, 2)
-}
-
-// WmCommission 小商店佣金
-func WmCommission(y int64) float64 {
-	return Round(float64(y)/100, 2)
-}
-
-// WmGoodsOriginalPrice 小商店商品原价
-func WmGoodsOriginalPrice(y int64) float64 {
-	return Round(float64(y)/100, 2)
-}
-
-// WmGoodsPrice 小商店商品券后价
-func WmGoodsPrice(y int64) float64 {
-	return Round(float64(y)/100, 2)
-}
-
-// JdCommission 京东佣金
-func JdCommission(y, x float64) float64 {
-	return Round((y*x)/100, 2)
-}

godecimal_test.go

@@ -1,16 +0,0 @@
-package godecimal
-
-import (
-	"testing"
-)
-
-func TestDecimal(t *testing.T) {
-	t.Log(Decimal(2.3333))
-}
-
-func TestRound(t *testing.T) {
-	t.Log(Round(2.3333, 1))
-	t.Log(Round(2.3333, 2))
-	t.Log(Round(2.3333, 3))
-	t.Log(Round(2.3333, 4))
-}

math.go

@@ -0,0 +1,38 @@
+package godecimal
+
+import "math"
+
+// Abs 取绝对值
+func Abs(x float64) float64 {
+	return math.Abs(x)
+}
+
+// Floor 向下取整
+func Floor(x float64) float64 {
+	return math.Floor(x)
+}
+
+// Ceil 向上取整
+func Ceil(x float64) float64 {
+	return math.Ceil(x)
+}
+
+// Round 就近取整
+func Round(x float64) float64 {
+	return math.Round(x)
+}
+
+// RoundPoint 就近取整并保留小数点
+func RoundPoint(x float64) float64 {
+	return math.Round(x*100) / 100
+}
+
+// Max 取较大值
+func Max(x, y float64) float64 {
+	return math.Max(x, y)
+}
+
+// Min 取较小值
+func Min(x, y float64) float64 {
+	return math.Min(x, y)
+}

math_test.go

@@ -0,0 +1,26 @@
+package godecimal
+
+import "testing"
+
+func TestMath(t *testing.T) {
+	t.Log(Abs(111))
+	t.Log(Abs(-111))
+
+	t.Log(Floor(3.4))
+	t.Log(Floor(3.5))
+
+	t.Log(Ceil(3.4))
+	t.Log(Ceil(3.5))
+
+	t.Log(Round(3.4))
+	t.Log(Round(3.5))
+
+	t.Log(RoundPoint(3.4))
+	t.Log(RoundPoint(3.5))
+	t.Log(RoundPoint(3.14))
+	t.Log(RoundPoint(3.14159))
+
+	t.Log(Max(4, 3))
+
+	t.Log(Min(4, 3))
+}

version.go

@@ -1,3 +1,3 @@
 package godecimal
 
-const Version = "1.0.0"
+const Version = "1.0.3"