| // Copyright 2010 The Apache Software Foundation |
| // |
| // 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://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License 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 org.apache.tapestry5.func; |
| |
| @SuppressWarnings("unchecked") |
| class LazyConcat<T> implements LazyFunction<T> |
| { |
| private final Flow<T> left, right; |
| |
| public LazyConcat(Flow<T> first, Flow<? extends T> second) |
| { |
| this.left = first; |
| this.right = (Flow<T>) second; |
| } |
| |
| @Override |
| public LazyContinuation<T> next() |
| { |
| if (left.isEmpty()) |
| { |
| if (right.isEmpty()) |
| return null; |
| |
| return new LazyContinuation<T>(new LazyFirst<T>(right), new LazyWalk<T>(right.rest())); |
| } |
| |
| return new LazyContinuation<T>(new LazyFirst<T>(left), new LazyConcat<T>(left.rest(), right)); |
| } |
| |
| } |