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    
015    package org.apache.tapestry5.plastic;
016    
017    /**
018     * Callback used with {@link InstructionBuilder#doWhile(Condition, WhileCallback)}.
019     */
020    public 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    }