v0.0.543

dataext/ringBuffer.go

@@ -26,6 +26,20 @@ func (rb *RingBuffer[T]) Push(item T) {
 	rb.head = (rb.head + 1) % rb.capacity
 }
 
+func (rb *RingBuffer[T]) PushPop(item T) *T {
+	if rb.size < rb.capacity {
+		rb.size++
+		rb.items[rb.head] = item
+		rb.head = (rb.head + 1) % rb.capacity
+		return nil
+	} else {
+		prev := rb.items[rb.head]
+		rb.items[rb.head] = item
+		rb.head = (rb.head + 1) % rb.capacity
+		return &prev
+	}
+}
+
 func (rb *RingBuffer[T]) Peek() (T, bool) {
 	if rb.size == 0 {
 		return *new(T), false
@@ -96,3 +110,35 @@ func (rb *RingBuffer[T]) Iter2() iter.Seq2[int, T] {
 		}
 	}
 }
+
+func (rb *RingBuffer[T]) Remove(fnEqual func(v T) bool) int {
+	// Mike [2024-11-13]: I *really* tried to write an in-place algorithm to remove elements
+	//                    But after carful consideration, I left that as an exercise for future readers
+	//                    It is, suprisingly, non-trivial, especially because the head-ptr must be weirdly updated
+	//                    And out At() method does not work correctly with {head<>0 && size<capacity}
+
+	dc := 0
+	b := make([]T, rb.capacity)
+	bsize := 0
+
+	for i := 0; i < rb.size; i++ {
+		comp := rb.At(i)
+		if fnEqual(comp) {
+			dc++
+		} else {
+			b[bsize] = comp
+			bsize++
+		}
+	}
+
+	if dc == 0 {
+		return 0
+	}
+
+	rb.items = b
+	rb.size = bsize
+	rb.head = bsize % rb.capacity
+
+	return dc
+
+}