README
¶
Small gophers that help you write Go programs
Functional-style utilities. You can think of this as the missing toplevel builtins, things you can find e.g. in Python.
Requires Go 1.18 (generics).
All functions have short, familiar names, like Assert or Filter,
and you are encouraged to dot-import the module for easy access.
Handling errors
package main
import (
. "github.com/rollcat/gophers"
)
Now instead of writing this:
x, err := GetX()
if err != nil {
panic(err)
}
You can write this:
x := Must(GetX())
It will crash just the same.
Functional style
For those, who do not believe that Go has a Lisp nature,
I present the familiar repertoire of Map, Filter, and Reduce.
There is also a handful of other small utilities such as GroupBy
(which classifies elements from a list into a map, according to a
function), or SortBy (duh).
These are all made possible because of the introduction of generics.
Documentation
¶
Index ¶
- func Assert(err error)
- func BContains[T comparable](xs []T, x T) bool
- func BSearch[T comparable](xs []T, x T) int
- func Compose[A, B, C any](f func(A) B, g func(B) C) func(A) C
- func Compose3[A, B, C, D any](f func(A) B, g func(B) C, h func(C) D) func(A) D
- func Contains[T comparable](xs []T, x T) bool
- func Filter[T any](f func(T) bool, xs []T) []T
- func GroupBy[T any, K comparable](f func(T) K, xs []T) map[K][]T
- func Map[A, B any](f func(A) B, xs []A) []B
- func MapKeys[K comparable, V any](m map[K]V) (keys []K)
- func MapValues[K comparable, V any](m map[K]V) (values []V)
- func Must[T any](x T, err error) T
- func Must2[T1, T2 any](x1 T1, x2 T2, err error) (T1, T2)
- func Reduce[A, V any](f func(A, V) A, acc A, xs []V) A
- func SlicePop[T any](xs []T, idx int) ([]T, T)
- func Sort[T constraints.Ordered](xs []T)
- func SortBy[T any, K constraints.Ordered](xs []T, f func(T) K)
- func Sorted[T constraints.Ordered](xs []T) []T
- func Uniq[T comparable](xs []T) []T
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func BContains ¶
func BContains[T comparable](xs []T, x T) bool
Check if xs (which must be sorted) contains x, using binary search.
func BSearch ¶
func BSearch[T comparable](xs []T, x T) int
Search for the position of x in xs, using binary search. The input slice xs must be sorted. Return len(xs) if no match is found.
func Compose ¶
func Compose[A, B, C any](f func(A) B, g func(B) C) func(A) C
Create a function that composes f and g into a single function n, such that n(x) = g(f(x)).
func Compose3 ¶
func Compose3[A, B, C, D any](f func(A) B, g func(B) C, h func(C) D) func(A) D
Create a function that composes f, g and h into a single function n, such that n(x) = h(g(f(x))).
func Contains ¶
func Contains[T comparable](xs []T, x T) bool
Check if x exists in xs (linear time).
func GroupBy ¶
func GroupBy[T any, K comparable](f func(T) K, xs []T) map[K][]T
Group xs by key function f into a map of arrays. Relative order of xs in map values is preserved.
func Map ¶
func Map[A, B any](f func(A) B, xs []A) []B
Apply f to each element in xs and return an array with the results.
func MapValues ¶
func MapValues[K comparable, V any](m map[K]V) (values []V)
Return the values in the map.
func Reduce ¶
func Reduce[A, V any](f func(A, V) A, acc A, xs []V) A
Reduce the array of xs into an accumulator value using reducer f.
func SortBy ¶
func SortBy[T any, K constraints.Ordered](xs []T, f func(T) K)
Sort xs in place, comparing elements using keyfunc f.
func Uniq ¶
func Uniq[T comparable](xs []T) []T
Return only unique values in xs, disregarding order.
Types ¶
This section is empty.
Source Files