/*
 * Copyright Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags and
 * the COPYRIGHT.txt file distributed with this work.
 *
 * Licensed 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.teiid.query.sql.symbol;

import org.teiid.query.sql.LanguageObject;

/**
 * This is the interface for an expression in a SQL string.  Expressions can be of several
 * types (see subclasses), but all expressions have a type.  These types are used for
 * type checking.
 */
public interface Expression extends LanguageObject {

    /**
     * Get the return type of this expression.
     * @return Java class may be null prior to being resolved
     */
    Class<?> getType();

}
