com.github.chrisbrenton.grappa.parsetree.visitors

Class VisitorRunner

java.lang.Object

com.github.chrisbrenton.grappa.parsetree.visitors.VisitorRunner

public final class VisitorRunner
extends java.lang.Object

Run one or more visitor(s) on a given parse tree

The scenario to visit a parse tree is as follows:

• create an instance of this class;
• register one or more Visitors;
• call one of the run methods.

The order in which the nodes of a parse tree are visited depend on the visit order that you define. By default, this will be a postorder traversal.

Implementation details

When you run() the visitors, you determine an order to traverse the node; the order is an instance of VisitOrder which, given the root node, will generate an Iterable over all the nodes using its visit() method.

The nodes are then fed to an EventBus, to which the visitors you will have registered in the runner will subscribe to. When a node is posted on the bus (see EventBus.post(Object)), the appropriate methods will be invoked with this node as an argument.

See Also:

Visitor, VisitOrder

Constructor Summary

Constructors

Constructor and Description
VisitorRunner(ParseNode node) Constructor

Method Summary

Modifier and Type	Method and Description
void	registerVisitor(Visitor visitor) Add one visitor to this runner
void	run() Visit all nodes of the parse tree using a postorder traversal
void	run(VisitOrder visitOrder) Visit all nodes of the parse tree in a given visit order

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VisitorRunner

public VisitorRunner(ParseNode node)

Constructor

Parameters:

node - the node at the root of the parse tree

Method Detail

registerVisitor

public void registerVisitor(Visitor visitor)

Add one visitor to this runner

Parameters:

visitor - the visitor

run

public void run(VisitOrder visitOrder)

Visit all nodes of the parse tree in a given visit order

Parameters:

visitOrder - the order

run

public void run()

Visit all nodes of the parse tree using a postorder traversal