edu.mit.ai.psg.jeva.examples
Class TraceEvalHookBase

java.lang.Object
  |
  +--edu.mit.ai.psg.jeva.JevaVisitorBase
        |
        +--edu.mit.ai.psg.jeva.examples.TraceEvalHookBase

Direct Known Subclasses:

TraceAllEvalHook

public abstract class TraceEvalHookBase

extends JevaVisitorBase

TraceEvalHookBase.java provides indented printing for trace output.

Call trace(IJevaNode, Object) from the visit method of the type(s) of node you want traced (default is to trace all nodes: visit(IJevaNode, Object)). Subclasses override visit methods to specify which nodes they want traced.

trace(IJevaNode, Object) will set up a printwriter with the appropriate indenting, and calls indentedTrace(PrintWriter, IJevaNode, Object). Subclasses can override this trace method to specify how they want the node to print out.

Default output stream is System.err.

Constructor Summary

TraceEvalHookBase()

TraceEvalHookBase(PrintWriter pw)

Method Summary

abstract Object	indentedTrace(PrintWriter pw, IJevaNode node, Object data) Override this method to customize how to print out node.
Object	trace(IJevaNode node, Object data) prints out "->" on calls, and "<-" on results, and calls indentedTrace(PrintWriter, IJevaNode, Object) with an appropriately indenting printwriter.
Object	visit(IJevaNode node, Object data) default method: trace all nodes.

Methods inherited from class edu.mit.ai.psg.jeva.JevaVisitorBase

visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit

Methods inherited from class java.lang.Object

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

Constructor Detail

TraceEvalHookBase

public TraceEvalHookBase()

TraceEvalHookBase

public TraceEvalHookBase(PrintWriter pw)

Method Detail

visit

public Object visit(IJevaNode node,
                    Object data)

default method: trace all nodes. To trace less, override this method with one that simply return null;, and override the methods for the nodes you want to trace to just call return trace(node, data);

Overrides:

visit in class JevaVisitorBase

trace

public Object trace(IJevaNode node,
                    Object data)

prints out "->" on calls, and "<-" on results, and calls indentedTrace(PrintWriter, IJevaNode, Object) with an appropriately indenting printwriter.

indentedTrace

public abstract Object indentedTrace(PrintWriter pw,
                                     IJevaNode node,
                                     Object data)

Override this method to customize how to print out node.