Further abstract some calls in SLL

This is a part of a rework that should make it
safer to use and properly managed.

src/sequencer/base/mml_executor.cpp

@@ -125,9 +125,7 @@ MMLEvent *MMLExecutor::on_repeat_all(MMLEvent *p_event) {
 }
 
 MMLEvent *MMLExecutor::on_repeat_begin(MMLEvent *p_event) {
-	SinglyLinkedList<int> *counter = SinglyLinkedList<int>::alloc(p_event->get_data());
-	counter->link(_repeat_counters);
-	_repeat_counters = counter;
+	_repeat_counters = _repeat_counters->prepend(p_event->get_data());
 
 	return p_event->get_next();
 }

src/sequencer/simml_envelope_table.cpp

@@ -38,17 +38,14 @@ void SiMMLEnvelopeTable::copy_from(const Ref<SiMMLEnvelopeTable> &p_source) {
 		return;
 	}
 
-	SinglyLinkedList<int> *curr_source = p_source->head;
-	SinglyLinkedList<int> *curr_destination = nullptr;
-	for (; curr_source != p_source->tail; curr_source = curr_source->next()) {
-		SinglyLinkedList<int> *sll_value = SinglyLinkedList<int>::alloc(curr_source->value);
-		if (curr_destination) {
-			curr_destination->link(sll_value);
-			curr_destination = sll_value;
-		} else {
-			head = sll_value;
-			curr_destination = head;
-		}
+	head = p_source->head->clone_element();
+
+	SinglyLinkedList<int> *target = head;
+	SinglyLinkedList<int> *current = p_source->head->next();
+
+	while (current != p_source->tail) {
+		target = target->append(current->value);
+		current = current->next();
 	}
 }
 

src/templates/singly_linked_list.h

@@ -32,7 +32,7 @@ class SinglyLinkedList {
 	// NOTE: Original code called it `i`. There is no special accessor, so we opt for a better public name.
 	T value = 0;
 
-	static SinglyLinkedList<T> *alloc(int p_value = 0) {
+	static SinglyLinkedList<T> *alloc(T p_value) {
 		SinglyLinkedList<T> *ret;
 
 		if (_free_list) {
@@ -139,6 +139,12 @@ class SinglyLinkedList {
 		return _next;
 	}
 
+	SinglyLinkedList<T> *prepend(T p_value) {
+		SinglyLinkedList<T> *head = alloc(p_value);
+		head->_next = this;
+		return head;
+	}
+
 	void link(SinglyLinkedList<T> *p_element) {
 		_next = p_element;
 	}
@@ -147,6 +153,12 @@ class SinglyLinkedList {
 		_next = nullptr;
 	}
 
+	//
+
+	SinglyLinkedList<T> *clone_element() {
+		return alloc(value);
+	}
+
 	SinglyLinkedList(T p_value) {
 		value = p_value;
 	}