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slices ​

Generic slice utility functions.

Import ​

go
import "github.com/foomo/go/slices"

API ​

Filter ​

go
func Filter[T any](items []T, fn func(T) bool) []T

Returns a new slice containing only the elements for which the predicate returns true.

Map ​

go
func Map[T, U any](items []T, fn func(T) U) []U

Returns a new slice with each element transformed by the given function.

GroupBy ​

go
func GroupBy[T any, K comparable](items []T, keyFn func(T) K) map[K][]T

Groups elements into a map keyed by the result of the key function.

Examples ​

Filter ​

go
evens := slices.Filter([]int{1, 2, 3, 4, 5}, func(n int) bool {
	return n%2 == 0
})
fmt.Println(evens) // [2 4]

Map ​

go
doubled := slices.Map([]int{1, 2, 3}, func(n int) int {
	return n * 2
})
fmt.Println(doubled) // [2 4 6]

GroupBy ​

go
type item struct {
	name     string
	category string
}

items := []item{
	{"apple", "fruit"},
	{"carrot", "vegetable"},
	{"banana", "fruit"},
}

groups := slices.GroupBy(items, func(i item) string {
	return i.category
})

fmt.Println(len(groups))              // 2
fmt.Println(len(groups["fruit"]))     // 2
fmt.Println(len(groups["vegetable"])) // 1