x

README

Extra

Collection of extra packages that implement some useful features that are missing in the standard library.

Installation

go get github.com/gravitton/x

Usage

Heap

Generic Heap backed by slice implementation using container/heap package from existing proposal.

package main

import (
	"cmp"
	"fmt"

	"github.com/gravitton/x/container/heap"
)

type priorityItem struct {
	value    string
	priority int
	index    int
}

func (i *priorityItem) Compare(item *priorityItem) int {
	return cmp.Compare(i.priority, item.priority)
}

func (i *priorityItem) setIndex(index int) {
	i.index = index
}

func main() {
	pq := heap.NewComparable[priorityItem]()
	pq.SetIndex((*priorityItem).setIndex)

	pq.Push(&priorityItem{value: "banana", priority: 3})
	pq.Push(&priorityItem{value: "apple", priority: 2})
	pq.Push(&priorityItem{value: "pear", priority: 4})

	orange := &priorityItem{value: "orange", priority: 1}
	pq.Push(orange)
	orange.priority = 5
	pq.Fix(orange.index)

	for pq.Len() > 0 {
		item := pq.Pop()
		fmt.Printf("%.2d:%s\n", item.priority, item.value)
	}

	// 02:apple 03:banana 04:pear 05:orange
}

Queue

Generic queue implementation. It is just a wrapper around []T with some extra methods.

package main

import (
	"fmt"

	"github.com/gravitton/x/container/queue"
)

func main() {
	q := queue.New[int]()
	q.Push(2)
	q.Push(3)
	q.Push(1)

	for q.Len() > 0 {
		val := q.Pop()
		fmt.Println(val)
	}

	// 2 3 1
}

Map

Generic Map method for slices.

package main

import (
	"fmt"
	"math"

	"github.com/gravitton/x/slices"
)

func main() {
	sf := slices.Map([]float64{1.1, 2.6, 3.4}, math.Round)
	si := slices.Map(sf, func(x float64) int {
		return 10 + int(x)
	})

	fmt.Println(si)

	// [11, 13, 13]
}

Credits

• Tomáš Novotný
• All Contributors

License

The MIT License (MIT). Please see License File for more information.