/**
* Traverses the tree of <code>root</code> via the depth first strategy and executes the
* corresponding semantic actions. If an ambiguity node is found an {@link ParseError} is thrown.
*
* @param root {@link AbstractParseNode} the root of the internal parse forest <code>currentNode
* </code> belongs to
*/
private void traverse(AbstractParseNode root) {
// check if root is an ambiguity node
if (root.isAmbNode()) {
System.out.println("\tAn ambiguity was detected...");
throw new ParseError("An ambiguity was detected.\n" + printParseForest(root));
}
// enter root
stack.enterNode(getRule(root.getLabel()), root, graphBuilder);
executeSemanticAction(root, stack.getCurrentElement().getRepresentedNode());
while (!stack.isEmpty()) {
((GraphBuilderBaseImpl) graphBuilder).addToSizeOfInternalParseForest(1);
if (stack.getCurrentElement().haveAllChildrenBeenHandeled()) {
// leave node
stack.leaveNode();
// return to parent node
stack.returnToNode();
if (stack.isEmpty()) {
break;
}
executeSemanticAction(root, stack.getCurrentElement().getRepresentedNode());
} else {
AbstractParseNode nextChild =
stack
.getCurrentElement()
.getRepresentedNode()
.getChildren()[stack.getCurrentElement().getNumberOfChildren()];
// check if nextChild is an ambiguity node
if (nextChild.isAmbNode()) {
System.out.println("\tAn ambiguity was detected...");
throw new ParseError("An ambiguity was detected.\n" + printParseForest(root));
}
stack.enterNode(getRule(nextChild.getLabel()), nextChild, graphBuilder);
executeSemanticAction(root, stack.getCurrentElement().getRepresentedNode());
}
}
}
