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 * Callback used with {@link InstructionBuilder#doWhile(Condition, WhileCallback)}.
019 */
020public interface WhileCallback
021{
022    /**
023     * Creates the code to be evaluated by the {@link Condition}; often this involves
024     * loading a value from a variable or argument, or {@link InstructionBuilder#dupe()}'ing the
025     * top value on the stack.
026     */
027    void buildTest(InstructionBuilder builder);
028
029    /**
030     * Provides the main code executed inside the loop.
031     */
032    void buildBody(InstructionBuilder builder);
033}