yield can retun null

src/Latte/Compiler/Node.php

@@ -22,7 +22,6 @@ abstract public function print(PrintContext $context): string;
 
 	public function &getIterator(): \Generator
 	{
-		return;
 		yield;
 	}
 }

src/Latte/Compiler/NodeTraverser.php

@@ -56,6 +56,9 @@ private function traverseNode(Node $node): Node
 
 		if ($children) {
 			foreach ($node as &$subnode) {
+				if ($subnode === null) {
+					continue;
+				}
 				$subnode = $this->traverseNode($subnode);
 				if ($this->stop) {
 					break;

src/Latte/Compiler/Nodes/AuxiliaryNode.php

@@ -28,6 +28,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Compiler/Nodes/Html/AttributeNode.php

@@ -41,8 +41,6 @@ public function print(PrintContext $context): string
 	public function &getIterator(): \Generator
 	{
 		yield $this->name;
-		if ($this->value) {
-			yield $this->value;
-		}
+		yield $this->value;
 	}
 }

src/Latte/Compiler/Nodes/Html/ElementNode.php

@@ -116,14 +116,8 @@ private function printStartTag(PrintContext $context): string
 	public function &getIterator(): \Generator
 	{
 		yield $this->tagNode;
-		if ($this->customName) {
-			yield $this->customName;
-		}
-		if ($this->attributes) {
-			yield $this->attributes;
-		}
-		if ($this->content) {
-			yield $this->content;
-		}
+		yield $this->customName;
+		yield $this->attributes;
+		yield $this->content;
 	}
 }

src/Latte/Compiler/Nodes/NopNode.php

@@ -22,6 +22,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Compiler/Nodes/Php/ArgumentNode.php

@@ -37,9 +37,7 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		if ($this->name) {
-			yield $this->name;
-		}
+		yield $this->name;
 		yield $this->value;
 	}
 }

src/Latte/Compiler/Nodes/Php/Expression/ArrayAccessNode.php

@@ -34,8 +34,6 @@ public function print(PrintContext $context): string
 	public function &getIterator(): \Generator
 	{
 		yield $this->expr;
-		if ($this->index) {
-			yield $this->index;
-		}
+		yield $this->index;
 	}
 }

src/Latte/Compiler/Nodes/Php/Expression/ArrayItemNode.php

@@ -44,9 +44,7 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		if ($this->key) {
-			yield $this->key;
-		}
+		yield $this->key;
 		yield $this->value;
 	}
 }

src/Latte/Compiler/Nodes/Php/Expression/ArrayNode.php

@@ -86,9 +86,7 @@ public function print(PrintContext $context): string
 	public function &getIterator(): \Generator
 	{
 		foreach ($this->items as &$item) {
-			if ($item) {
-				yield $item;
-			}
+			yield $item;
 		}
 	}
 }

src/Latte/Compiler/Nodes/Php/Expression/ClosureNode.php

@@ -63,11 +63,7 @@ public function &getIterator(): \Generator
 			yield $item;
 		}
 
-		if ($this->returnType) {
-			yield $this->returnType;
-		}
-		if ($this->expr) {
-			yield $this->expr;
-		}
+		yield $this->returnType;
+		yield $this->expr;
 	}
 }

src/Latte/Compiler/Nodes/Php/Expression/TernaryNode.php

@@ -40,11 +40,7 @@ public function print(PrintContext $context): string
 	public function &getIterator(): \Generator
 	{
 		yield $this->cond;
-		if ($this->if) {
-			yield $this->if;
-		}
-		if ($this->else) {
-			yield $this->else;
-		}
+		yield $this->if;
+		yield $this->else;
 	}
 }

src/Latte/Compiler/Nodes/Php/IdentifierNode.php

@@ -37,6 +37,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Compiler/Nodes/Php/NameNode.php

@@ -90,6 +90,6 @@ public function toCodeString(): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Compiler/Nodes/Php/ParameterNode.php

@@ -43,12 +43,8 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		if ($this->type) {
-			yield $this->type;
-		}
+		yield $this->type;
 		yield $this->var;
-		if ($this->default) {
-			yield $this->default;
-		}
+		yield $this->default;
 	}
 }

src/Latte/Compiler/Nodes/Php/ScalarNode.php

@@ -14,6 +14,6 @@ abstract class ScalarNode extends ExpressionNode
 {
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Compiler/Nodes/Php/SuperiorTypeNode.php

@@ -30,6 +30,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Compiler/Nodes/TextNode.php

@@ -38,6 +38,6 @@ public function isWhitespace(): bool
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/ContentTypeNode.php

@@ -75,6 +75,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/DebugbreakNode.php

@@ -46,8 +46,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		if ($this->condition) {
-			yield $this->condition;
-		}
+		yield $this->condition;
 	}
 }

src/Latte/Essential/Nodes/DumpNode.php

@@ -51,8 +51,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		if ($this->expression) {
-			yield $this->expression;
-		}
+		yield $this->expression;
 	}
 }

src/Latte/Essential/Nodes/FirstLastSepNode.php

@@ -70,12 +70,8 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		if ($this->width) {
-			yield $this->width;
-		}
+		yield $this->width;
 		yield $this->then;
-		if ($this->else) {
-			yield $this->else;
-		}
+		yield $this->else;
 	}
 }

src/Latte/Essential/Nodes/ForNode.php

@@ -78,9 +78,7 @@ public function &getIterator(): \Generator
 			yield $item;
 		}
 
-		if ($this->condition) {
-			yield $this->condition;
-		}
+		yield $this->condition;
 
 		foreach ($this->next as &$item) {
 			yield $item;

src/Latte/Essential/Nodes/ForeachNode.php

@@ -143,13 +143,9 @@ private function printArgs(PrintContext $context): string
 	public function &getIterator(): \Generator
 	{
 		yield $this->expression;
-		if ($this->key) {
-			yield $this->key;
-		}
+		yield $this->key;
 		yield $this->value;
 		yield $this->content;
-		if ($this->else) {
-			yield $this->else;
-		}
+		yield $this->else;
 	}
 }

src/Latte/Essential/Nodes/IfChangedNode.php

@@ -134,8 +134,6 @@ public function &getIterator(): \Generator
 	{
 		yield $this->conditions;
 		yield $this->then;
-		if ($this->else) {
-			yield $this->else;
-		}
+		yield $this->else;
 	}
 }

src/Latte/Essential/Nodes/IfNode.php

@@ -173,8 +173,6 @@ public function &getIterator(): \Generator
 	{
 		yield $this->condition;
 		yield $this->then;
-		if ($this->else) {
-			yield $this->else;
-		}
+		yield $this->else;
 	}
 }

src/Latte/Essential/Nodes/IncludeBlockNode.php

@@ -131,9 +131,7 @@ private function printBlockFrom(PrintContext $context, string $modArg): string
 	public function &getIterator(): \Generator
 	{
 		yield $this->name;
-		if ($this->from) {
-			yield $this->from;
-		}
+		yield $this->from;
 		yield $this->args;
 		yield $this->modifier;
 	}

src/Latte/Essential/Nodes/RawPhpNode.php

@@ -47,6 +47,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/RollbackNode.php

@@ -38,6 +38,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/SwitchNode.php

@@ -109,9 +109,7 @@ public function &getIterator(): \Generator
 	{
 		yield $this->expression;
 		foreach ($this->cases as [&$case, , &$stmt]) {
-			if ($case) {
-				yield $case;
-			}
+			yield $case;
 			yield $stmt;
 		}
 	}

src/Latte/Essential/Nodes/TemplatePrintNode.php

@@ -40,6 +40,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/TemplateTypeNode.php

@@ -39,6 +39,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/TraceNode.php

@@ -36,6 +36,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/TryNode.php

@@ -68,8 +68,6 @@ public function print(PrintContext $context): string
 	public function &getIterator(): \Generator
 	{
 		yield $this->try;
-		if ($this->else) {
-			yield $this->else;
-		}
+		yield $this->else;
 	}
 }

src/Latte/Essential/Nodes/VarPrintNode.php

@@ -41,6 +41,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

src/Latte/Essential/Nodes/VarTypeNode.php

@@ -37,6 +37,6 @@ public function print(PrintContext $context): string
 
 	public function &getIterator(): \Generator
 	{
-		false && yield;
+		yield;
 	}
 }

tests/helpers.php

@@ -126,7 +126,9 @@ function exportAST(Node $node)
 	};
 	$res = $prop ? $prop . "\n" : '';
 	foreach ($node as $sub) {
-		$res .= rtrim(exportAST($sub), "\n") . "\n";
+		if ($sub !== null) {
+			$res .= rtrim(exportAST($sub), "\n") . "\n";
+		}
 	}
 
 	return substr($node::class, strrpos($node::class, '\\') + 1, -4)