Precedence.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;

import com.amazonaws.annotation.Immutable;

/**
 * <a href=
 * "http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html#ConditionExpressionReference"
 * >Precedence</a> of various Conditions.
 */
@Immutable
enum Precedence {
    Comparator(700),    // = <> < <= > >=
    IN(600),
    BETWEEN(500),
    Function(400),  // attribute_exists attribute_not_exists begins_with contains
    Parentheses(300),
    NOT(200),
    AND(100),
    OR(0),
    ;
    /**
     * The higher this value, the higher the precedence.
     */
    private final int value;

    private Precedence(int value) { this.value = value; }

    int value() {
        return value;
    }
}