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 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package com.sun.tools.javac.tree;

import com.sun.tools.javac.util.*;
import com.sun.tools.javac.tree.JCTree.*;

A subclass of Tree.Visitor, this class defines
 a general tree scanner pattern. Translation proceeds recursively in
 left-to-right order down a tree. There is one visitor method in this class
 for every possible kind of tree node.  To obtain a specific
 scanner, it suffices to override those visitor methods which
 do some interesting work. The scanner class itself takes care of all
 navigational aspects.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/** A subclass of Tree.Visitor, this class defines
 *  a general tree scanner pattern. Translation proceeds recursively in
 *  left-to-right order down a tree. There is one visitor method in this class
 *  for every possible kind of tree node.  To obtain a specific
 *  scanner, it suffices to override those visitor methods which
 *  do some interesting work. The scanner class itself takes care of all
 *  navigational aspects.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class TreeScanner extends Visitor {

    
Visitor method: Scan a single node.
/** Visitor method: Scan a single node.
     */
    public void scan(JCTree tree) {
        if(tree!=null) tree.accept(this);
    }

    
Visitor method: scan a list of nodes.
/** Visitor method: scan a list of nodes.
     */
    public void scan(List<? extends JCTree> trees) {
        if (trees != null)
        for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
            scan(l.head);
    }


/* ***************************************************************************
 * Visitor methods
 ****************************************************************************/

    public void visitTopLevel(JCCompilationUnit tree) {
        scan(tree.defs);
    }

    public void visitPackageDef(JCPackageDecl tree) {
        scan(tree.annotations);
        scan(tree.pid);
    }

    @Override
    public void visitModuleDef(JCModuleDecl tree) {
        scan(tree.mods);
        scan(tree.qualId);
        scan(tree.directives);
    }

    @Override
    public void visitExports(JCExports tree) {
        scan(tree.qualid);
        scan(tree.moduleNames);
    }

    @Override
    public void visitOpens(JCOpens tree) {
        scan(tree.qualid);
        scan(tree.moduleNames);
    }

    @Override
    public void visitProvides(JCProvides tree) {
        scan(tree.serviceName);
        scan(tree.implNames);
    }

    @Override
    public void visitRequires(JCRequires tree) {
        scan(tree.moduleName);
    }

    @Override
    public void visitUses(JCUses tree) {
        scan(tree.qualid);
    }

    public void visitImport(JCImport tree) {
        scan(tree.qualid);
    }

    public void visitClassDef(JCClassDecl tree) {
        scan(tree.mods);
        scan(tree.typarams);
        scan(tree.extending);
        scan(tree.implementing);
        scan(tree.defs);
    }

    public void visitMethodDef(JCMethodDecl tree) {
        scan(tree.mods);
        scan(tree.restype);
        scan(tree.typarams);
        scan(tree.recvparam);
        scan(tree.params);
        scan(tree.thrown);
        scan(tree.defaultValue);
        scan(tree.body);
    }

    public void visitVarDef(JCVariableDecl tree) {
        scan(tree.mods);
        scan(tree.vartype);
        scan(tree.nameexpr);
        scan(tree.init);
    }

    public void visitSkip(JCSkip tree) {
    }

    public void visitBlock(JCBlock tree) {
        scan(tree.stats);
    }

    public void visitDoLoop(JCDoWhileLoop tree) {
        scan(tree.body);
        scan(tree.cond);
    }

    public void visitWhileLoop(JCWhileLoop tree) {
        scan(tree.cond);
        scan(tree.body);
    }

    public void visitForLoop(JCForLoop tree) {
        scan(tree.init);
        scan(tree.cond);
        scan(tree.step);
        scan(tree.body);
    }

    public void visitForeachLoop(JCEnhancedForLoop tree) {
        scan(tree.var);
        scan(tree.expr);
        scan(tree.body);
    }

    public void visitLabelled(JCLabeledStatement tree) {
        scan(tree.body);
    }

    public void visitSwitch(JCSwitch tree) {
        scan(tree.selector);
        scan(tree.cases);
    }

    public void visitCase(JCCase tree) {
        scan(tree.pats);
        scan(tree.stats);
    }

    public void visitSwitchExpression(JCSwitchExpression tree) {
        scan(tree.selector);
        scan(tree.cases);
    }

    public void visitSynchronized(JCSynchronized tree) {
        scan(tree.lock);
        scan(tree.body);
    }

    public void visitTry(JCTry tree) {
        scan(tree.resources);
        scan(tree.body);
        scan(tree.catchers);
        scan(tree.finalizer);
    }

    public void visitCatch(JCCatch tree) {
        scan(tree.param);
        scan(tree.body);
    }

    public void visitConditional(JCConditional tree) {
        scan(tree.cond);
        scan(tree.truepart);
        scan(tree.falsepart);
    }

    public void visitIf(JCIf tree) {
        scan(tree.cond);
        scan(tree.thenpart);
        scan(tree.elsepart);
    }

    public void visitExec(JCExpressionStatement tree) {
        scan(tree.expr);
    }

    public void visitBreak(JCBreak tree) {
        scan(tree.value);
    }

    public void visitContinue(JCContinue tree) {
    }

    public void visitReturn(JCReturn tree) {
        scan(tree.expr);
    }

    public void visitThrow(JCThrow tree) {
        scan(tree.expr);
    }

    public void visitAssert(JCAssert tree) {
        scan(tree.cond);
        scan(tree.detail);
    }

    public void visitApply(JCMethodInvocation tree) {
        scan(tree.typeargs);
        scan(tree.meth);
        scan(tree.args);
    }

    public void visitNewClass(JCNewClass tree) {
        scan(tree.encl);
        scan(tree.typeargs);
        scan(tree.clazz);
        scan(tree.args);
        scan(tree.def);
    }

    public void visitNewArray(JCNewArray tree) {
        scan(tree.annotations);
        scan(tree.elemtype);
        scan(tree.dims);
        for (List<JCAnnotation> annos : tree.dimAnnotations)
            scan(annos);
        scan(tree.elems);
    }

    public void visitLambda(JCLambda tree) {
        scan(tree.body);
        scan(tree.params);
    }

    public void visitParens(JCParens tree) {
        scan(tree.expr);
    }

    public void visitAssign(JCAssign tree) {
        scan(tree.lhs);
        scan(tree.rhs);
    }

    public void visitAssignop(JCAssignOp tree) {
        scan(tree.lhs);
        scan(tree.rhs);
    }

    public void visitUnary(JCUnary tree) {
        scan(tree.arg);
    }

    public void visitBinary(JCBinary tree) {
        scan(tree.lhs);
        scan(tree.rhs);
    }

    public void visitTypeCast(JCTypeCast tree) {
        scan(tree.clazz);
        scan(tree.expr);
    }

    public void visitTypeTest(JCInstanceOf tree) {
        scan(tree.expr);
        scan(tree.clazz);
    }

    public void visitIndexed(JCArrayAccess tree) {
        scan(tree.indexed);
        scan(tree.index);
    }

    public void visitSelect(JCFieldAccess tree) {
        scan(tree.selected);
    }

    public void visitReference(JCMemberReference tree) {
        scan(tree.expr);
        scan(tree.typeargs);
    }

    public void visitIdent(JCIdent tree) {
    }

    public void visitLiteral(JCLiteral tree) {
    }

    public void visitTypeIdent(JCPrimitiveTypeTree tree) {
    }

    public void visitTypeArray(JCArrayTypeTree tree) {
        scan(tree.elemtype);
    }

    public void visitTypeApply(JCTypeApply tree) {
        scan(tree.clazz);
        scan(tree.arguments);
    }

    public void visitTypeUnion(JCTypeUnion tree) {
        scan(tree.alternatives);
    }

    public void visitTypeIntersection(JCTypeIntersection tree) {
        scan(tree.bounds);
    }

    public void visitTypeParameter(JCTypeParameter tree) {
        scan(tree.annotations);
        scan(tree.bounds);
    }

    @Override
    public void visitWildcard(JCWildcard tree) {
        scan(tree.kind);
        if (tree.inner != null)
            scan(tree.inner);
    }

    @Override
    public void visitTypeBoundKind(TypeBoundKind that) {
    }

    public void visitModifiers(JCModifiers tree) {
        scan(tree.annotations);
    }

    public void visitAnnotation(JCAnnotation tree) {
        scan(tree.annotationType);
        scan(tree.args);
    }

    public void visitAnnotatedType(JCAnnotatedType tree) {
        scan(tree.annotations);
        scan(tree.underlyingType);
    }

    public void visitErroneous(JCErroneous tree) {
    }

    public void visitLetExpr(LetExpr tree) {
        scan(tree.defs);
        scan(tree.expr);
    }

    public void visitTree(JCTree tree) {
        Assert.error();
    }
}