Add LinkedList Operators and Update Tests (#2438)

* Add LinkedList Operators and Update Tests
* add linkedlist printing and `@new` macros (single-line init and pool-capable)
* add linkedlist node and reg iterator; comparisons w/ ==
* Fix benchmarks. Drop random access to the linked list using []. Only return a direct array view.

---------

Co-authored-by: Christoffer Lerno <christoffer@aegik.com>

lib/std/collections/linkedlist.c3

@@ -2,13 +2,14 @@
 // Use of self source code is governed by the MIT license
 // a copy of which can be found in the LICENSE_STDLIB file.
 module std::collections::linkedlist{Type};
+import std::io;
 
 const ELEMENT_IS_EQUATABLE = types::is_equatable_type(Type);
 
-struct Node @private
+struct Node
 {
-	Node *next;
-	Node *prev;
+	Node* next;
+	Node* prev;
 	Type value;
 }
 
@@ -16,8 +17,31 @@ struct LinkedList
 {
 	Allocator allocator;
 	usz size;
-	Node *_first;
-	Node *_last;
+	Node* _first;
+	Node* _last;
+}
+
+fn usz? LinkedList.to_format(&self, Formatter* f) @dynamic
+{
+	usz len = f.print("{ ")!;
+	for (Node* node = self._first; node != null; node.next)
+	{
+		len += f.printf(node.next ? "%s, " : "s", node.value)!;
+	}
+	return len + f.print(" }");
+}
+
+macro LinkedList @new(Allocator allocator, Type[] #default_values = {})
+{
+	LinkedList new_list;
+	new_list.init(allocator);
+	new_list.push_all(#default_values);
+	return new_list;
+}
+
+macro LinkedList @tnew(Type[] #default_values = {})
+{
+	return @new(tmem, #default_values);
 }
 
 <*
@@ -68,6 +92,11 @@ fn void LinkedList.push_front(&self, Type value)
 	self.size++;
 }
 
+fn void LinkedList.push_front_all(&self, Type[] value)
+{
+	foreach_r (v : value) self.push_front(v);
+}
+
 fn void LinkedList.push(&self, Type value)
 {
 	Node *last = self._last;
@@ -85,6 +114,11 @@ fn void LinkedList.push(&self, Type value)
 	self.size++;
 }
 
+fn void LinkedList.push_all(&self, Type[] value)
+{
+	foreach (v : value) self.push(v);
+}
+
 fn Type? LinkedList.peek(&self) => self.first() @inline;
 fn Type? LinkedList.peek_last(&self) => self.last() @inline;
 
@@ -133,6 +167,7 @@ macro Node* LinkedList.node_at_index(&self, usz index)
 	while (index--) node = node.next;
 	return node;
 }
+
 <*
  @require index < self.size
 *>
@@ -141,6 +176,14 @@ fn Type LinkedList.get(&self, usz index)
 	return self.node_at_index(index).value;
 }
 
+<*
+ @require index < self.size
+*>
+fn Type* LinkedList.get_ref(&self, usz index)
+{
+	return &self.node_at_index(index).value;
+}
+
 <*
  @require index < self.size
 *>
@@ -149,6 +192,26 @@ fn void LinkedList.set(&self, usz index, Type element)
 	self.node_at_index(index).value = element;
 }
 
+fn usz? LinkedList.index_of(&self, Type t) @if(ELEMENT_IS_EQUATABLE)
+{
+	for (Node* node = self._first, usz i = 0; node != null; node = node.next, ++i)
+	{
+		if (node.value == t) return i;
+	}
+	return NOT_FOUND?;
+}
+
+fn usz? LinkedList.rindex_of(&self, Type t) @if(ELEMENT_IS_EQUATABLE)
+{
+	for (Node* node = self._last, usz i = self.size - 1; node != null; node = node.prev, --i)
+	{
+		if (node.value == t) return i;
+		if (i == 0) break;
+	}
+	return NOT_FOUND?;
+}
+
+
 <*
  @require index < self.size
 *>
@@ -334,3 +397,69 @@ fn void LinkedList.unlink(&self, Node* x) @private
 	self.free_node(x);
 	self.size--;
 }
+
+
+macro bool LinkedList.eq(&self, other) @operator(==) @if(ELEMENT_IS_EQUATABLE)
+{
+	Node* node1 = self._first;
+	Node* node2 = other._first;
+	while (true)
+	{
+		if (!node1) return node2 == null;
+		if (!node2) return false;
+		if (node1.value != node2.value) return false;
+		node1 = node1.next;
+		node2 = node2.next;
+	}
+	return true;
+}
+
+fn LinkedListArrayView LinkedList.array_view(&self)
+{
+	return { .list = self, .current_node = self._first };
+}
+
+
+struct LinkedListArrayView
+{
+	LinkedList* list;
+	Node* current_node;
+	usz current_index;
+}
+
+fn usz LinkedListArrayView.len(&self) @operator(len) => self.list.size;
+
+<*
+ @require index < self.list.size
+*>
+fn Type LinkedListArrayView.get(&self, usz index) @operator([])
+{
+	return *self.get_ref(index);
+}
+
+<*
+ @require index < self.list.size
+*>
+fn Type* LinkedListArrayView.get_ref(&self, usz index) @operator(&[])
+{
+	if (index == self.list.size - 1)
+	{
+		self.current_node = self.list._last;
+		self.current_index = index;
+	}
+
+	while (self.current_index != index)
+	{
+		switch
+		{
+			case index < self.current_index:   // reverse iteration
+				self.current_node = self.current_node.prev;
+				self.current_index--;
+			case index > self.current_index:
+				self.current_node = self.current_node.next;
+				self.current_index++;
+		}
+	}
+
+	return &self.current_node.value;
+}