feat: progress

pkg/lifo/lifo.go

@@ -0,0 +1,35 @@
+package lifo
+
+import "fmt"
+
+type LIFO[T any] []T
+
+func New[T any](items ...T) *LIFO[T] {
+	l := LIFO[T](items)
+	return &l
+}
+
+func (l *LIFO[T]) Push(item T) {
+	*l = append(*l, item)
+}
+
+func (l *LIFO[T]) Empty() bool {
+	return len(*l) == 0
+}
+
+func (l *LIFO[T]) MustPop() T {
+	var item T
+
+	*l, item = (*l)[:len(*l)-1], (*l)[len(*l)-1]
+	return item
+}
+
+func (l *LIFO[T]) Pop() (T, error) {
+	var item T
+
+	if l.Empty() {
+		return item, fmt.Errorf("stack is exhausted")
+	}
+
+	return l.MustPop(), nil
+}