    001// Copyright 2011 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007// http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.plastic;
    016
    017/**
    018 * Condition used with {@link InstructionBuilder#when(Condition, WhenCallback)}. Most conditions
    019 * pop the top element off the stack; some pop two elements.
    020 */
    021public enum Condition
    022{
    023    /** Is the top element of the stack null? */
    024    NULL,
    025
    026    /** Is the top element of the stack non-null? */
    027    NON_NULL,
    028
    029    /** Is the top element of the stack the integer zero? */
    030    ZERO,
    031
    032    /** Is the top element of the stack not the integer zero? */
    033    NON_ZERO,
    034
    035    /**
    036     * Compare two integer elements on the stack; branch if the deeper
    037     * element is less than the top element.
    038     */
    039    LESS_THAN,
    040
    041    /**
    042     * Compare two integer elements on the stack; branch if the deeper
    043     * element equal to the top element.
    044     */
    045    EQUAL,
    046
    047    /**
    048     * Compare two integer elements on the stack; branch if the deeper
    049     * element is not equal to the top element.
    050     */
    051    NOT_EQUAL,
    052
    053    /**
    054     * Compare two integer elements on the stack; branch if the deeper
    055     * element is greater than the top element.
    056     */
    057    GREATER;
    058}