ScopeHandler.java #2

/*
 * ScopeHandler.java
 *
 * comments here.
 *
 * @author   Michiaki Tatsubori
 * @version  %VERSION% %DATE%
 * @see      java.lang.Object
 *
 * COPYRIGHT 1998 by Michiaki Tatsubori, ALL RIGHTS RESERVED.
 */
package openjava.ptree.util;


import java.util.Stack;
import openjava.mop.*;
import openjava.ptree.*;


/**
 * The class <code>ScopeHandler</code>
 * <p>
 * For example
 * <pre>
 * </pre>
 * <p>
 *
 * @author   Michiaki Tatsubori
 * @version  1.0
 * @since    %SOFTWARE% 1.0
 * @see openjava.ptree.ParseTree
 * @see openjava.ptree.util.ParseTreeVisitor
 * @see openjava.ptree.util.EvaluationShuttle
 */
public abstract class ScopeHandler extends EvaluationShuttle
{
    private Stack env_nest = new Stack();

    public ScopeHandler( Environment base_env ) {
	super( base_env );
    }

    protected final void pushClosedEnvironment() {
	env_nest.push( getEnvironment() );
	setEnvironment( new ClosedEnvironment( getEnvironment() ) );
    }

    protected final void push( Environment env ) {
	env_nest.push( getEnvironment() );
	setEnvironment( env );
    }

    protected final void pop() {
	setEnvironment( (Environment) env_nest.pop() );
    }

    /* in walking down through parse tree */

    /* compilation unit */
    public CompilationUnit evaluateDown(CompilationUnit ptree)
        throws ParseTreeException
    {
        ClassDeclaration pubclazz = ptree.getPublicClass();
        String name = (pubclazz != null) ? pubclazz.getName()
	    : "<no public class>";
        FileEnvironment fenv
	    = new FileEnvironment(getEnvironment(), ptree, name);

        push( fenv );

        return ptree;
    }

    /* class declaration */
    public ClassDeclaration evaluateDown( ClassDeclaration ptree )
	throws ParseTreeException
    {
	ClassEnvironment env
	    = new ClassEnvironment( getEnvironment(), ptree.getName() );
	MemberDeclarationList mdecls = ptree.getBody();
	for (int i = 0; i < mdecls.size(); ++i) {
	    MemberDeclaration m = mdecls.get( i );
	    if (! (m instanceof ClassDeclaration))  continue;
	    ClassDeclaration inner = (ClassDeclaration) m;
	    env.recordMemberClass( inner.getName() );
	}
	push( env );
	return ptree;
    }

    /* class body contents */
    public MemberDeclaration evaluateDown( MethodDeclaration ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public MemberDeclaration evaluateDown( ConstructorDeclaration ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public MemberDeclaration evaluateDown( MemberInitializer ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    /* statements */
    public Statement evaluateDown( Block ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public Statement evaluateDown( SwitchStatement ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public Statement evaluateDown( IfStatement ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public Statement evaluateDown( WhileStatement ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public Statement evaluateDown( DoWhileStatement ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public Statement evaluateDown( ForStatement ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public Statement evaluateDown( TryStatement ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    public Statement evaluateDown( SynchronizedStatement ptree )
	throws ParseTreeException
    {
	pushClosedEnvironment();
	return ptree;
    }

    /* query */
    public openjava.ptree.Expression evaluateDown( QueryExpression ptree )
	throws ParseTreeException
    {
	QueryEnvironment env = new QueryEnvironment( getEnvironment(), ptree );
	push( env );
	return ptree;
    }

    /* in walking down through parse tree */

    /* class declaration */
    public CompilationUnit evaluateUp( CompilationUnit ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    /* class declaration */
    public ClassDeclaration evaluateUp( ClassDeclaration ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    /* class body contents */
    public MemberDeclaration evaluateUp( MethodDeclaration ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public MemberDeclaration evaluateUp( ConstructorDeclaration ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public MemberDeclaration evaluateUp( MemberInitializer ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    /* statements */
    public Statement evaluateUp( Block ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public Statement evaluateUp( SwitchStatement ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public Statement evaluateUp( IfStatement ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public Statement evaluateUp( WhileStatement ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public Statement evaluateUp( DoWhileStatement ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public Statement evaluateUp( ForStatement ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public Statement evaluateUp( TryStatement ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    public Statement evaluateUp( SynchronizedStatement ptree )
	throws ParseTreeException
    {
	pop();
	return ptree;
    }

    /* query */
    public Expression evaluateUp( QueryExpression ptree )
    {
	pop();
	return ptree;
    }
}