GoMap

map-example.go

package main

import (
	"fmt"
	"reflect"
)

type mapf func(interface{}) interface{}

func Map(in interface{}, fn mapf) interface{} {
	val := reflect.ValueOf(in)
	out := make([]interface{}, val.Len())
	for i := 0; i < val.Len(); i++ {
		out[i] = fn(val.Index(i).Interface())
	}
	return out
}

func main() {
	a := []int{1, 2, 3, 4}
	b := Map(a, func(val interface{}) interface{} {
		return val.(int) * 2
	})
 	fmt.Printf("Mapped %v to %v\n", a, b)
}