Adding Map method to List class

list_map.go

package main

import "container/list"

type MyList struct {
    *list.List
}

func (l *MyList) Map(f func(interface{}) interface{}) *MyList {
    nl := &MyList {list.New()}
    for e := l.Front(); e != nil; e = e.Next() {
        nl.PushBack(f(e.Value))
    }
    return nl
}