go-filter-map.go

package main

import "fmt"

type Language struct {
	ID     int
	Name   string
	Rating int
}

func Filter(vs []Language, f func(Language) bool) []Language {
	vsf := make([]Language, 0)
	for _, v := range vs {
		if f(v) {
			vsf = append(vsf, v)
		}
	}
	return vsf
}

func Map(vs []Language, f func(Language) string) []string {
	vsm := make([]string, len(vs))
	for i, v := range vs {
		vsm[i] = f(v)
	}
	return vsm
}

func main() {
	languages := []Language{
		Language{ID: 1, Name: "Javascript", Rating: 9},
		Language{ID: 2, Name: "Golang", Rating: 9},
		Language{ID: 3, Name: "Python", Rating: 8},
		Language{ID: 4, Name: "Rust", Rating: 8},
		Language{ID: 5, Name: "C#", Rating: 7},
		Language{ID: 5, Name: "Java", Rating: 5},
	}

	filtered := Filter(languages, func(lang Language) bool {
		return lang.Rating > 8
	})

	bestLanguages := Map(filtered, func(lang Language) string {
		return lang.Name
	})

	fmt.Println(bestLanguages)
}