UnitOfExpression.java

/*
 * Copyright 2015-2017 Amazon Technologies, Inc.
 *
 * 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://aws.amazon.com/apache2.0
 *
 * This file 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 com.amazonaws.services.dynamodbv2.xspec;


/**
 * Unit of expression. A unit of expression is a building block for composing an
 * expression, such as update expression, condition (aka filter) expression, and
 * projection Expression.
 */
abstract class UnitOfExpression {
    /**
     * Returns this unit of expression as a string substituted if necessary with
     * tokens using the given substitution context.
     * 
     * @param context the substitution context which may get mutated as a side
     * effect upon completion of this method
     */
    abstract String asSubstituted(SubstitutionContext context);
}