【GoLang】函数作为 类型 和 值

package test

import (
    "fmt"
    "testing"
)

type testInt func(int) bool

func isOdd(integer int) bool {
    if integer%2 == 0 {
        return false
    }
    return true
}

func isEven(integer int) bool {
    if integer%2 == 0 {
        return true
    }
    return false
}

func filter(slice []int, f testInt) []int {
    var result []int
    for _, value := range slice {
        if f(value) {
            result = append(result, value)
        }
    }
    return result
}

func Test_Func(t *testing.T) {
    slice := []int{1, 2, 3, 4, 5, 7}
    fmt.Println("slice = ", slice)
    odd := filter(slice, isOdd)
    fmt.Println("Odd elements of slice are: ", odd)
    even := filter(slice, isEven)
    fmt.Println("Even elements of slice are: ", even)
}

slice =  [1 2 3 4 5 7]
Odd elements of slice are:  [1 3 5 7]
Even elements of slice are:  [2 4]