package main
import (
"fmt"
"strings"
)
func Index(vs []string, t string) int {
for i, v := range vs {
if v == t {
return i
}
}
return -1
}
func Include(vs []string, t string) bool {
return Index(vs, t) >= 0
}
func Any(vs []string, f func(string) bool) bool {
for _, v := range vs {
if f(v) {
return true
}
}
return false
}
func All(vs []string, f func(string) bool) bool {
for _, v := range vs {
if !f(v) {
return false
}
}
return true
}
func Filter(vs []string, f func(string) bool) []string {
vsf := make([]string, 0)
for _, v := range vs {
if f(v) {
vsf = append(vsf, v)
}
}
return vsf
}
func Map(vs []string, f func(string) string) []string {
vsm := make([]string, len(vs))
for i, v := range vs {
vsm[i] = f(v)
}
return vsm
}
func main() {
var strs = []string{"peach", "apple", "pear", "plum"}
fmt.Println(Index(strs, "pear"))
fmt.Println(Include(strs, "grape"))
fmt.Println(Any(strs, func(v string) bool {
return strings.HasPrefix(v, "p")
}))
fmt.Println(All(strs, func(v string) bool {
return strings.HasPrefix(v, "p")
}))
fmt.Println(Filter(strs, func(v string) bool {
return strings.Contains(v, "e")
}))
fmt.Println(Map(strs, strings.ToUpper))
}$ go run collection-functions.go
2
false
true
false
[peach apple pear]
[PEACH APPLE PEAR PLUM]