 }
 
 
+/**
+ * Sets up to two virtual properties.  This is represented as a single node as
+ * both constraints must be known when generating SetRuntimeProp nodes.  When
+ * generating SetRuntimeProps, if only one property is given, the span
+ * (width/height) property of the target object should remain untouched unless
+ * specifically nominated.
+ */
 class SetVirtualProps implements ASTNode
 {
     public var object:Object;

}


class ArithmeticOptimizer extends ASTFilter
{
    private var _replacements:int;

}


/**
 * Rounds the value of a node to the nearest integer, with half-integer values
 * rounding towards positive infinity.
 */
class Round implements ASTNode
{
    public var child:ASTNode;
