adventofcode/helpers/queue.go

package aoc

import "fmt"

type Queue[T any] struct {
	items []T
}

func NewQueue[T any](items []T) *Queue[T] {
	return &Queue[T]{
		items: items,
	}
}

func (q *Queue[T]) Len() int {
	return len(q.items)
}

func (q *Queue[T]) Push(item T) {
	q.items = append(q.items, item)
}
func (q *Queue[T]) Pop() T {
	var x T
	x, q.items = q.items[len(q.items)-1], q.items[:len(q.items)-1]
	return x
}
func (q *Queue[T]) Unshift(item T) {
	q.items = append([]T{item}, q.items...)
}
func (q *Queue[T]) Shift() T {
	var x T
	x, q.items = q.items[0], q.items[1:]
	return x
}

func (q *Queue[T]) Append(items []T) {
	q.items = append(q.items, items...)
}
func (q *Queue[T]) Copy() *Queue[T] {
	ret := &Queue[T]{
		items: make([]T, len(q.items)),
	}
	copy(ret.items, q.items)
	return ret
}
func (q *Queue[T]) Cut(at, count int) []T {
	ret := q.items[at : at+count]
	q.items = append(q.items[:at], q.items[at+count:]...)
	return ret
}
func (q *Queue[T]) DeleteAt(idx int) {
	q.items = append(q.items[:idx], q.items[idx+1:]...)
}

//	func (q *Queue[T]) Delete(item T) {
//		for i := range q.items {
//			if q.items[i] == item {
//				q.items = append(q.items[:i], q.items[i+1:]...)
//				return
//			}
//		}
//	}
func (q *Queue[T]) Expand(at, by int) {
	q.items = append(q.items[:at], append(make([]T, by), q.items[at:]...)...)
}
func (q *Queue[T]) Extend(by int) {
	q.items = append(q.items, make([]T, by)...)
}
func (q *Queue[T]) FilterInPlace(keep func(item T) bool) {
	n := 0
	for _, x := range q.items {
		if keep(x) {
			q.items[n] = x
			n++
		}
	}
	q.items = q.items[:n]
}
func (q *Queue[T]) Insert(item T, location int) {
	q.InsertVector([]T{item}, location)
}
func (q *Queue[T]) InsertVector(items []T, location int) {
	q.items = append(q.items[:location], append(items, q.items[location:]...)...)
}

func (q Queue[T]) String() string {
	res := "[ "
	for i := range q.items {
		res = fmt.Sprintf("%s %v", res, q.items[i])
	}
	return fmt.Sprintf("%s ]", res)
}