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 * Copyright (c) 1999, 2011, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

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 translator pattern. Translation proceeds recursively in

 *  left-to-right order down a tree, constructing translated nodes by

 *  overwriting existing ones. There is one visitor method in this class

 *  for every possible kind of tree node.  To obtain a specific

 *  translator, it suffices to override those visitor methods which

 *  do some interesting work. The translator 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 TreeTranslator extends JCTree.Visitor {

    /** Visitor result field: a tree

     */

    protected JCTree result;

    /** Visitor method: Translate a single node.

     */

    @SuppressWarnings("unchecked")

    public <T extends JCTree> T translate(T tree) {

        if (tree == null) {

            return null;

        } else {

            tree.accept(this);

            JCTree result = this.result;

            this.result = null;

            return (T)result; // XXX cast

        }

    }

    /** Visitor method: translate a list of nodes.

     */

    public <T extends JCTree> List<T> translate(List<T> trees) {

        if (trees == null) return null;

        for (List<T> l = trees; l.nonEmpty(); l = l.tail)

            l.head = translate(l.head);

        return trees;

    }

    /**  Visitor method: translate a list of variable definitions.

     */

    public List<JCVariableDecl> translateVarDefs(List<JCVariableDecl> trees) {

        for (List<JCVariableDecl> l = trees; l.nonEmpty(); l = l.tail)

            l.head = translate(l.head);

        return trees;

    }

    /**  Visitor method: translate a list of type parameters.

     */

    public List<JCTypeParameter> translateTypeParams(List<JCTypeParameter> trees) {

        for (List<JCTypeParameter> l = trees; l.nonEmpty(); l = l.tail)

            l.head = translate(l.head);

        return trees;

    }

    /**  Visitor method: translate a list of case parts of switch statements.

     */

    public List<JCCase> translateCases(List<JCCase> trees) {

        for (List<JCCase> l = trees; l.nonEmpty(); l = l.tail)

            l.head = translate(l.head);

        return trees;

    }

    /**  Visitor method: translate a list of catch clauses in try statements.

     */

    public List<JCCatch> translateCatchers(List<JCCatch> trees) {

        for (List<JCCatch> l = trees; l.nonEmpty(); l = l.tail)

            l.head = translate(l.head);

        return trees;

    }

    /**  Visitor method: translate a list of catch clauses in try statements.

     */

    public List<JCAnnotation> translateAnnotations(List<JCAnnotation> trees) {

        for (List<JCAnnotation> l = trees; l.nonEmpty(); l = l.tail)

            l.head = translate(l.head);

        return trees;

    }

/* ***************************************************************************

 * Visitor methods

 ****************************************************************************/

    public void visitTopLevel(JCCompilationUnit tree) {

        tree.pid = translate(tree.pid);

        tree.defs = translate(tree.defs);

        result = tree;

    }

    public void visitImport(JCImport tree) {

        tree.qualid = translate(tree.qualid);

        result = tree;

    }

    public void visitClassDef(JCClassDecl tree) {

        tree.mods = translate(tree.mods);

        tree.typarams = translateTypeParams(tree.typarams);

        tree.extending = translate(tree.extending);

        tree.implementing = translate(tree.implementing);

        tree.defs = translate(tree.defs);

        result = tree;

    }

    public void visitMethodDef(JCMethodDecl tree) {

        tree.mods = translate(tree.mods);

        tree.restype = translate(tree.restype);

        tree.typarams = translateTypeParams(tree.typarams);

        tree.params = translateVarDefs(tree.params);

        tree.thrown = translate(tree.thrown);

        tree.body = translate(tree.body);

        result = tree;

    }

    public void visitVarDef(JCVariableDecl tree) {

        tree.mods = translate(tree.mods);

        tree.vartype = translate(tree.vartype);

        tree.init = translate(tree.init);

        result = tree;

    }

    public void visitSkip(JCSkip tree) {

        result = tree;

    }

    public void visitBlock(JCBlock tree) {

        tree.stats = translate(tree.stats);

        result = tree;

    }

    public void visitDoLoop(JCDoWhileLoop tree) {

        tree.body = translate(tree.body);

        tree.cond = translate(tree.cond);

        result = tree;

    }

    public void visitWhileLoop(JCWhileLoop tree) {

        tree.cond = translate(tree.cond);

        tree.body = translate(tree.body);

        result = tree;

    }

    public void visitForLoop(JCForLoop tree) {

        tree.init = translate(tree.init);

        tree.cond = translate(tree.cond);

        tree.step = translate(tree.step);

        tree.body = translate(tree.body);

        result = tree;

    }

    public void visitForeachLoop(JCEnhancedForLoop tree) {

        tree.var = translate(tree.var);

        tree.expr = translate(tree.expr);

        tree.body = translate(tree.body);

        result = tree;

    }

    public void visitLabelled(JCLabeledStatement tree) {

        tree.body = translate(tree.body);

        result = tree;

    }

    public void visitSwitch(JCSwitch tree) {

        tree.selector = translate(tree.selector);

        tree.cases = translateCases(tree.cases);

        result = tree;

    }

    public void visitCase(JCCase tree) {

        tree.pat = translate(tree.pat);

        tree.stats = translate(tree.stats);

        result = tree;

    }

    public void visitSynchronized(JCSynchronized tree) {

        tree.lock = translate(tree.lock);

        tree.body = translate(tree.body);

        result = tree;

    }

    public void visitTry(JCTry tree) {

        tree.resources = translate(tree.resources);

        tree.body = translate(tree.body);

        tree.catchers = translateCatchers(tree.catchers);

        tree.finalizer = translate(tree.finalizer);

        result = tree;

    }

    public void visitCatch(JCCatch tree) {

        tree.param = translate(tree.param);

        tree.body = translate(tree.body);

        result = tree;

    }

    public void visitConditional(JCConditional tree) {

        tree.cond = translate(tree.cond);

        tree.truepart = translate(tree.truepart);

        tree.falsepart = translate(tree.falsepart);

        result = tree;

    }

    public void visitIf(JCIf tree) {

        tree.cond = translate(tree.cond);

        tree.thenpart = translate(tree.thenpart);

        tree.elsepart = translate(tree.elsepart);

        result = tree;

    }

    public void visitExec(JCExpressionStatement tree) {

        tree.expr = translate(tree.expr);

        result = tree;

    }

    public void visitBreak(JCBreak tree) {

        result = tree;

    }

    public void visitContinue(JCContinue tree) {

        result = tree;

    }

    public void visitReturn(JCReturn tree) {

        tree.expr = translate(tree.expr);

        result = tree;

    }

    public void visitThrow(JCThrow tree) {

        tree.expr = translate(tree.expr);

        result = tree;

    }

    public void visitAssert(JCAssert tree) {

        tree.cond = translate(tree.cond);

        tree.detail = translate(tree.detail);

        result = tree;

    }

    public void visitApply(JCMethodInvocation tree) {

        tree.meth = translate(tree.meth);

        tree.args = translate(tree.args);

        result = tree;

    }

    public void visitNewClass(JCNewClass tree) {

        tree.encl = translate(tree.encl);

        tree.clazz = translate(tree.clazz);

        tree.args = translate(tree.args);

        tree.def = translate(tree.def);

        result = tree;

    }

    public void visitNewArray(JCNewArray tree) {

        tree.elemtype = translate(tree.elemtype);

        tree.dims = translate(tree.dims);

        tree.elems = translate(tree.elems);

        result = tree;

    }

    public void visitParens(JCParens tree) {

        tree.expr = translate(tree.expr);

        result = tree;

    }

    public void visitAssign(JCAssign tree) {

        tree.lhs = translate(tree.lhs);

        tree.rhs = translate(tree.rhs);

        result = tree;

    }

    public void visitAssignop(JCAssignOp tree) {

        tree.lhs = translate(tree.lhs);

        tree.rhs = translate(tree.rhs);

        result = tree;

    }

    public void visitUnary(JCUnary tree) {

        tree.arg = translate(tree.arg);

        result = tree;

    }

    public void visitBinary(JCBinary tree) {

        tree.lhs = translate(tree.lhs);

        tree.rhs = translate(tree.rhs);

        result = tree;

    }

    public void visitTypeCast(JCTypeCast tree) {

        tree.clazz = translate(tree.clazz);

        tree.expr = translate(tree.expr);

        result = tree;

    }

    public void visitTypeTest(JCInstanceOf tree) {

        tree.expr = translate(tree.expr);

        tree.clazz = translate(tree.clazz);

        result = tree;

    }

    public void visitIndexed(JCArrayAccess tree) {

        tree.indexed = translate(tree.indexed);

        tree.index = translate(tree.index);

        result = tree;

    }

    public void visitSelect(JCFieldAccess tree) {

        tree.selected = translate(tree.selected);

        result = tree;

    }

    public void visitIdent(JCIdent tree) {

        result = tree;

    }

    public void visitLiteral(JCLiteral tree) {

        result = tree;

    }

    public void visitTypeIdent(JCPrimitiveTypeTree tree) {

        result = tree;

    }

    public void visitTypeArray(JCArrayTypeTree tree) {

        tree.elemtype = translate(tree.elemtype);

        result = tree;

    }

    public void visitTypeApply(JCTypeApply tree) {

        tree.clazz = translate(tree.clazz);

        tree.arguments = translate(tree.arguments);

        result = tree;

    }

        tree.alternatives = translate(tree.alternatives);

        result = tree;

    }

    public void visitTypeParameter(JCTypeParameter tree) {

        tree.bounds = translate(tree.bounds);

        result = tree;

    }

    @Override

    public void visitWildcard(JCWildcard tree) {

        tree.kind = translate(tree.kind);

        tree.inner = translate(tree.inner);

        result = tree;

    }

    @Override

    public void visitTypeBoundKind(TypeBoundKind tree) {

        result = tree;

    }

    public void visitErroneous(JCErroneous tree) {

        result = tree;

    }

    public void visitLetExpr(LetExpr tree) {

        tree.defs = translateVarDefs(tree.defs);

        tree.expr = translate(tree.expr);

        result = tree;

    }

    public void visitModifiers(JCModifiers tree) {

        tree.annotations = translateAnnotations(tree.annotations);

        result = tree;

    }

    public void visitAnnotation(JCAnnotation tree) {

        tree.annotationType = translate(tree.annotationType);

        tree.args = translate(tree.args);

        result = tree;

    }

    public void visitTree(JCTree tree) {

        throw new AssertionError(tree);

    }

}