Updates and small unit test

Library/Operators/Other/EmptyOperator.php

@@ -35,13 +35,7 @@ public function compile($expression, CompilationContext $compilationContext)
 	{
 		$compilationContext->headersManager->add('kernel/operators');
 
-		if (isset($expression['left']['type'])
-			&& $expression['left']['type'] == 'variable'
-		) {
-			return $this->evaluateVariableExpression($expression, $compilationContext);
-		}
-
-		return new CompiledExpression('int', '(0 == 0)', $expression);
+        return $this->evaluateVariableExpression($expression, $compilationContext);
 	}
 
     /**
@@ -61,10 +55,25 @@ protected function evaluateVariableExpression(
 		CompilationContext $compilationContext
 	) {
 
+        switch (true) {
+            case isset($expression['left']['left']['value'])
+                && isset($expression['left']['left']['type'])
+                && $expression['left']['left']['type'] == 'variable':
+
+                $name = $expression['left']['left']['value'];
+
+                break;
+
+            default:
+                throw new Exception(
+                    'Empty syntax not supported'
+                );
+        }
+
 		$variable = $compilationContext->symbolTable->getVariableForWrite(
-			$expression['left']['value'],
+			$name,
 			$compilationContext,
-			$expression['left']
+			$expression['left']['left']
 		);
 
 		return new CompiledExpression(

Library/SymbolTable.php

@@ -189,11 +189,11 @@ public function getVariableForRead($name, CompilationContext $compilationContext
 
 	/**
 	 * Return a variable in the symbol table, it will be used for a write operation
-	 * Some variables aren't writables themselves but their members do
+	 * Some variables aren't writable themselves but their members do
 	 *
 	 * @param string $name
-	 * @param array $statement
 	 * @param CompilationContext $compilationContext
+     * @param array $statement
 	 * @return \Variable
 	 */
 	public function getVariableForWrite($name, $compilationContext, $statement=null)

test/flow.zep

@@ -119,15 +119,15 @@ class Flow
 			if b {
 				let c = 1;
 				if c {
-					return 1;
+					return 654;
 				} else {
-					return 0;
+					return -1;
 				}
 			} else {
-				return 0;
+				return -2;
 			}
 		} else {
-			return 0;
+			return -3;
 		}
 	}
 
@@ -142,7 +142,7 @@ class Flow
 			if b {
 				let c = 1;
 				if c {
-					return 1;
+					return 987;
 				} else {
 					return 0;
 				}
@@ -158,26 +158,32 @@ class Flow
 	{
 		int a, b;
 		let a = 1, b = 2;
-		if a + b { return 1; }
+		if a + b { return -12; }
 		return 0;
 	}
 
 	public function testIf14()
 	{
 		var a, b;
 		let a = 1, b = 2;
-		if a + b { return 1; }
+		if a + b { return 74; }
 		return 0;
 	}
 
 	public function testIf15()
 	{
 		var a, b, c;
 		let a = 1, b = 2, c = 3;
-		if a + b + c { return 1; }
+		if a + b + c { return 89; }
 		return 0;
 	}
 
+	public function testIf16(var a)
+	{
+		if empty(a) { return true; }
+		return false;
+	}
+
 	public function testLoop1()
 	{
 		var a;

unit-tests/flow.php

@@ -11,7 +11,15 @@
 assert($t->testIf7() === 1);
 assert($t->testIf8() === 0);
 assert($t->testIf9() === 1);
-assert($t->testIf10() === 1);
+assert($t->testIf10() === 654);
+assert($t->testIf12() === 987);
+assert($t->testIf13() === -12);
+assert($t->testIf14() === 74);
+assert($t->testIf15() === 89);
+assert($t->testIf16(array()) === false);
+assert($t->testIf16('') === true);
+assert($t->testIf16(null) === true);
+assert($t->testIf16(' ') === false);
 
 assert($t->testLoop1() === true);
 assert($t->testLoop2() === 5);