geode-core/src/main/java/org/apache/geode/cache/query/internal/parse/ASTPostfix.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License. You may obtain a
 * copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */


package org.apache.geode.cache.query.internal.parse;

import antlr.Token;
import antlr.collections.AST;

import org.apache.geode.cache.query.internal.QCompiler;

/**
 * This handles paths, method invocations, and index operators that post-fix to a receiver
 * expression.
 */
public class ASTPostfix extends GemFireAST {
  private static final long serialVersionUID = 1100525641797867500L;

  public ASTPostfix() {}

  public ASTPostfix(Token t) {
    super(t);
  }

  @Override
  public void compile(QCompiler compiler) {
    AST child = getFirstChild();
    // push receiver, which is any CompiledValue
    ((GemFireAST) child).compile(compiler);
    child = child.getNextSibling();
    while (child != null) {
      switch (child.getType()) {
        case OQLLexerTokenTypes.METHOD_INV:
          // defer to method inv
          ((GemFireAST) child).compile(compiler);
          break;
        case OQLLexerTokenTypes.Identifier:
          compiler.appendPathComponent(child.getText());
          break;
        case OQLLexerTokenTypes.TOK_LBRACK:
          // push the indexExpr List on the stack
          // If the sibling is TOKEN_STAR, push null
          if (child.getFirstChild().getType() == OQLLexerTokenTypes.TOK_STAR) {
            compiler.pushNull();
          } else {
            ((GemFireAST) child).compile(compiler);
          }
          compiler.indexOp();
          break;
        default:
          throw new Error("unexpected node type:" + child.getType());
      }
      child = child.getNextSibling();
    }
  }

}