lancet/docs/convertor.md

Convertor

Package convertor contains some functions for data type convertion.

Source:

• https://github.com/duke-git/lancet/blob/main/convertor/convertor.go

Usage:

import (
    "github.com/duke-git/lancet/v2/convertor"
)

Index

• ColorHexToRGB
• ColorRGBToHex
• ToBool
• ToBytes
• ToChar
• ToChannel
• ToFloat
• ToInt
• ToJson
• ToMap
• ToPointer
• ToString
• StructToMap
• MapToSlice
• EncodeByte
• DecodeByte

Documentation

ColorHexToRGB

Convert color hex to color rgb.

Signature:

func ColorHexToRGB(colorHex string) (red, green, blue int)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    colorHex := "#003366"
	r, g, b := convertor.ColorHexToRGB(colorHex)

	fmt.Println(r, g, b)

	// Output:
	// 0 51 102
}

ColorRGBToHex

Convert color rgb to color hex.

Signature:

func ColorRGBToHex(red, green, blue int) string

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    r := 0
	g := 51
	b := 102
	colorHex := ColorRGBToHex(r, g, b)

	fmt.Println(colorHex)

	// Output:
	// #003366
}

ToBool

Convert string to bool. Use strconv.ParseBool.

Signature:

func ToBool(s string) (bool, error)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    cases := []string{"1", "true", "True", "false", "False", "0", "123", "0.0", "abc"}

	for i := 0; i < len(cases); i++ {
		result, _ := convertor.ToBool(cases[i])
		fmt.Println(result)
	}

	// Output:
	// true
	// true
	// true
	// false
	// false
	// false
	// false
	// false
	// false
}

ToBytes

Convert value to byte slice.

Signature:

func ToBytes(data any) ([]byte, error)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    bytesData, err := convertor.ToBytes("abc")
    if err != nil {
        fmt.Println(err)
    }

    fmt.Println(bytesData)

    // Output:
	// [97 98 99]
}

ToChar

Convert string to char slice.

Signature:

func ToChar(s string) []string

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    result1 := convertor.ToChar("")
	result2 := convertor.ToChar("abc")
	result3 := convertor.ToChar("1 2#3")

	fmt.Println(result1)
	fmt.Println(result2)
	fmt.Println(result3)

	// Output:
	// []
	// [a b c]
	// [1   2 # 3]
}

ToChannel

Convert a collection of elements to a read-only channel.

Signature:

func ToChannel[T any](array []T) <-chan T

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    ch := convertor.ToChannel([]int{1, 2, 3})
	result1 := <-ch
	result2 := <-ch
	result3 := <-ch

	fmt.Println(result1)
	fmt.Println(result2)
	fmt.Println(result3)

	// Output:
	// 1
	// 2
	// 3
}

ToFloat

Convert value to a float64 value. If param is a invalid floatable, will return 0.0 and error.

Signature:

func ToFloat(value any) (float64, error)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    result1, _ := convertor.ToFloat("")
	result2, err := convertor.ToFloat("abc")
	result3, _ := convertor.ToFloat("-1")
	result4, _ := convertor.ToFloat("-.11")
	result5, _ := convertor.ToFloat("1.23e3")
	result6, _ := convertor.ToFloat(true)

	fmt.Println(result1)
	fmt.Println(result2, err)
	fmt.Println(result3)
	fmt.Println(result4)
	fmt.Println(result5)
	fmt.Println(result6)

	// Output:
	// 0
	// 0 strconv.ParseFloat: parsing "": invalid syntax
	// -1
	// -0.11
	// 1230
	// 0
}

ToInt

Convert value to a int64 value. If param is a invalid intable, will return 0 and error.

Signature:

func ToInt(value any) (int64, error)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    result1, _ := convertor.ToInt("123")
	result2, _ := convertor.ToInt("-123")
	result3, _ := convertor.ToInt(float64(12.3))
	result4, err := convertor.ToInt("abc")
	result5, _ := convertor.ToInt(true)

	fmt.Println(result1)
	fmt.Println(result2)
	fmt.Println(result3)
	fmt.Println(result4, err)
	fmt.Println(result5)

	// Output:
	// 123
	// -123
	// 12
	// 0 strconv.ParseInt: parsing "": invalid syntax
	// 0
}

ToJson

Convert interface to json string. If param can't be converted, will return "" and error.

Signature:

func ToJson(value any) (string, error)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    aMap := map[string]int{"a": 1, "b": 2, "c": 3}
	result, err := ToJson(aMap)

	if err != nil {
		fmt.Printf("%v", err)
	}

	fmt.Println(result)

	// Output:
	// {"a":1,"b":2,"c":3}
}

ToMap

Convert a slice of structs to a map based on iteratee function.

Signature:

func ToMap[T any, K comparable, V any](array []T, iteratee func(T) (K, V)) map[K]V

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    type Message struct {
        name string
        code int
    }
    messages := []Message{
        {name: "Hello", code: 100},
        {name: "Hi", code: 101},
    }

    result := convertor.ToMap(messages, func(msg Message) (int, string) {
        return msg.code, msg.name
    })

    fmt.Println(result)

    // Output:
	// map[100:Hello 101:Hi]
}

ToPointer

Returns a pointer to passed value.

Signature:

func ToPointer[T any](value T) *T

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    result := convertor.ToPointer(123)
    fmt.Println(*result) 
    
    // Output:
	// 123
}

ToString

ToString convert value to string, for number, string, []byte, will convert to string. For other type (slice, map, array, struct) will call json.Marshal

Signature:

func ToString(value any) string

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    result1 := convertor.ToString("")
	result2 := convertor.ToString(nil)
	result3 := convertor.ToString(0)
	result4 := convertor.ToString(1.23)
	result5 := convertor.ToString(true)
	result6 := convertor.ToString(false)
	result7 := convertor.ToString([]int{1, 2, 3})

	fmt.Println(result1)
	fmt.Println(result2)
	fmt.Println(result3)
	fmt.Println(result4)
	fmt.Println(result5)
	fmt.Println(result6)
	fmt.Println(result7)

	// Output:
	//
	//
	// 0
	// 1.23
	// true
	// false
	// [1,2,3]
}

StructToMap

Convert struct to map, only convert exported field, struct field tag `json` should be set.

Signature:

func StructToMap(value any) (map[string]any, error)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    type People struct {
		Name string `json:"name"`
		age  int
	}
	p := People{
		"test",
		100,
	}
	pm, _ := convertor.StructToMap(p)

	fmt.Println(pm)

	// Output:
	// map[name:test]
}

MapToSlice

Convert a map to a slice based on iteratee function.

Signature:

func MapToSlice[T any, K comparable, V any](aMap map[K]V, iteratee func(K, V) T) []T

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    aMap := map[string]int{"a": 1, "b": 2, "c": 3}
    result := MapToSlice(aMap, func(key string, value int) string {
        return key + ":" + strconv.Itoa(value)
    })

    fmt.Println(result) //[]string{"a:1", "b:2", "c:3"}
}

EncodeByte

Encode data to byte slice.

Signature:

func EncodeByte(data any) ([]byte, error)

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    byteData, _ := convertor.EncodeByte("abc")
    fmt.Println(byteData)

    // Output:
	// [6 12 0 3 97 98 99]
}

DecodeByte

Decode byte data to target object. target should be a pointer instance.

Signature:

func DecodeByte(data []byte, target any) error

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/convertor"
)

func main() {
    var result string
	byteData := []byte{6, 12, 0, 3, 97, 98, 99}
	
    err := convertor.DecodeByte(byteData, &result)
    if err != nil {
		return
	}

    fmt.Println(result)
    
    // Output:
	// abc
}