content: /*
   * 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.ambari.server.api.predicate;
  
  import java.util.Collection;
  
  import org.apache.ambari.server.controller.spi.Predicate;
  
  /**
   * Compiler which takes a query expression as input and produces a predicate instance as output.
   */
  public class PredicateCompiler {
  
    /**
     * Lexer instance used to translate expressions into stream of tokens.
     */
    private QueryLexer lexer = new QueryLexer();
  
    /**
     * Parser instance used to produce a predicate instance from a stream of tokens.
     */
    private QueryParser parser = new QueryParser();
  
    /**
     * Generate a predicate from a query expression.
     *
     * @param exp  query expression
     *
     * @return a predicate instance
     * @throws InvalidQueryException if unable to compile the expression
     */
    public Predicate compile(String exp) throws InvalidQueryException {
      return parser.parse(lexer.tokens(exp));
    }
  
    /**
     * Generate a predicate from a query expression.
     *
     * @param exp               query expression
     * @param ignoredProperties  collection of property names to ignore
     *
     * @return a predicate instance
     * @throws InvalidQueryException if unable to compile the expression
     */
    public Predicate compile(String exp, Collection<String> ignoredProperties) throws InvalidQueryException {
      return parser.parse(lexer.tokens(exp, ignoredProperties));
    }
  }
  