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Documentation

Index

• func All[T any](collection []T, f func(T) bool) bool
• func KeyBy[T any, K comparable](collection []T, keygen func(T) K) map[K]T
• func Map[T any, R any](collection []T, mapper func(T) R) []R
• func Reduce[T, R any](collection []T, reducer func(T, R) R, initial R) R
• func Reject[T any](collection []T, rejecter func(T) bool) []T
• func Select[T any](collection []T, selecter func(T) bool) []T

Examples

• All
• KeyBy
• Map
• Reduce
• Reject
• Select

Functions

func All

func All[T any](collection []T, f func(T) bool) bool

All returns true if all elements in collection return true when passed to f, otherwise it returns false.

Example

collection := []int{1, 2, 3}

res := All(collection, func(i int) bool {
	return i > 0
})

fmt.Println(res)

Output:

true

func KeyBy

func KeyBy[T any, K comparable](collection []T, keygen func(T) K) map[K]T

KeyBy calls keygen on each element of collection, setting the result of f as the key in the returned map, and the element as the value.

Example

collection := []string{"first", "second", "last"}

res := KeyBy(collection, func(s string) int {
	return len(s)
})

fmt.Println(res)

Output:

map[4:last 5:first 6:second]

func Map

func Map[T any, R any](collection []T, mapper func(T) R) []R

Map calls mapper on each element on collection, returning a new collection with the results of each call to mapper.

Example

collection := []int{1, 2, 3}

res := Map(collection, func(i int) int {
	return i * 2
})

fmt.Println(res)

Output:

[2 4 6]

func Reduce

func Reduce[T, R any](collection []T, reducer func(T, R) R, initial R) R

Reduce accepts a slice of values, a function that accepts an element of the slice and an accumulater, and an initial value for the accumulator. The result of each call to reducer is passed as the value to the next iteration.

Example

collection := []int{1, 2, 3}

res := Reduce(collection, func(i, acc int) int {
	return acc + i
}, 0)

fmt.Println(res)

Output:

6

func Reject

func Reject[T any](collection []T, rejecter func(T) bool) []T

Reject calls rejecter on each element of collection, returning a new slice for all elements where f returns false.

Example

collection := []int{1, 2, 3, 4}

res := Reject(collection, func(i int) bool {
	return i%2 == 0
})

fmt.Println(res)

Output:

[1 3]

func Select

func Select[T any](collection []T, selecter func(T) bool) []T

Select calls selecter on each element of collection, returning a new slice for all elements where f returns true.

Example

collection := []int{1, 2, 3, 4}

res := Select(collection, func(i int) bool {
	return i%2 == 0
})

fmt.Println(res)

Output:

[2 4]