lancet/docs/formatter.md

Formatter

formatter contains some functions for data formatting.

Source:

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

Usage:

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

Index

• Comma
• Pretty
• PrettyToWriter

Documentation

Comma

Add comma to a number value by every 3 numbers from right to left. ahead by symbol char. if value is a invalid number string like "aa", return empty string.

Signature:

func Comma[T constraints.Float | constraints.Integer | string](value T, symbol string) string

Example:

package main

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

func main() {
    result1 := formatter.Comma("123", "")
    result2 := formatter.Comma("12345", "$")
    result3 := formatter.Comma(1234567, "￥")

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

    // Output:
    // 123
    // $12,345
    // ￥1,234,567
}

Pretty

Pretty data to JSON string.

Signature:

func Pretty(v any) (string, error)

Example:

package main

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

func main() {
    result1, _ := formatter.Pretty([]string{"a", "b", "c"})
    result2, _ := formatter.Pretty(map[string]int{"a": 1})

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

    // Output:
    // [
    //     "a",
    //     "b",
    //     "c"
    // ]
    // {
    //     "a": 1
    // }
}

PrettyToWriter

Pretty encode data to writer.

Signature:

func PrettyToWriter(v any, out io.Writer) error

Example:

package main

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

func main() {
    type User struct {
        Name string `json:"name"`
        Aage uint   `json:"age"`
    }
    user := User{Name: "King", Aage: 10000}

    buf := &bytes.Buffer{}
    err := formatter.PrettyToWriter(user, buf)

    fmt.Println(buf)
    fmt.Println(err)

    // Output:
    // {
    //     "name": "King",
    //     "age": 10000
    // }
    //
    // <nil>
}