new file: linear/queue.go

linear/queue.go

@@ -0,0 +1,71 @@
+package linear
+
+import (
+	"errors"
+)
+
+// Queue []Type{} -> creates a Queue with no fixed size
+// Implemented as slice
+type Queue[T any] struct {
+	capacity  uint8
+	container []T
+}
+
+// QueueFixed -> QueueFixed[Type](size) creates a Queue with no fixed size
+func QueueFixed[T any](value uint8) *Queue[T] {
+	return &Queue[T]{
+		capacity:  value,
+		container: make([]T, 0, value),
+	}
+}
+
+// Add() -> enqeues an item, returns err if queue if full
+func (q *Queue[T]) Add(item T) error {
+	if q.capacity > 0 && q.capacity <= uint8(len(q.container)) {
+		return errors.New("Queue full")
+	}
+
+	q.container = append(q.container, item)
+	return nil
+}
+
+// Peek() -> returns the upcoming item
+func (q *Queue[T]) Peek() (T, bool) {
+	if len(q.container) <= 0 {
+		var zero T
+		return zero, false
+	}
+
+	return q.container[0], true
+}
+
+// Pull() -> returns the upcoming item and removes it from Queue
+func (q *Queue[T]) Pull() (T, error) {
+	if len(q.container) <= 0 {
+		var zero T
+		return zero, errors.New("Queue is empty")
+	}
+
+	upcoming := q.container[0]
+	q.container = q.container[1:]
+
+	return upcoming, nil
+}
+
+// Cull() -> removes the last item , returns it and err
+func (q *Queue[T]) Cull() (T, error) {
+	if len(q.container) <= 0 {
+		var zero T
+		return zero, errors.New("Queue is empty")
+	}
+
+	last := q.container[len(q.container)-1]
+	q.container = q.container[0 : len(q.container)-1]
+
+	return last, nil
+}
+
+// Size() -> returns size of queue
+func (q *Queue[T]) Size() int {
+	return len(q.container)
+}