content: /*
   * Copyright (c) 2001, 2020, 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 openjdk.tools.javac.tree;
  
  import openjdk.tools.javac.util.*;
  import openjdk.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.
   *
   *  <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.
       */
      public void scan(JCTree tree) {
          if(tree!=null) tree.accept(this);
      }
  
      /** 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.permitting);
          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.labels);
          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) {
      }
  
      public void visitYield(JCYield 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.pattern);
      }
  
      public void visitBindingPattern(JCBindingPattern tree) {
          scan(tree.var);
      }
  
      @Override
      public void visitDefaultCaseLabel(JCDefaultCaseLabel tree) {
      }
  
      @Override
      public void visitParenthesizedPattern(JCParenthesizedPattern that) {
          scan(that.pattern);
      }
  
      @Override
      public void visitGuardPattern(JCGuardPattern that) {
          scan(that.patt);
          scan(that.expr);
      }
  
      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();
      }
  }
  