// GPars - Groovy Parallel Systems
//
// Copyright © 2008-11  The original author or authors
//
// 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 groovyx.gpars.samples.dataflow.thenChaining

import groovyx.gpars.dataflow.DataflowVariable

/**
 * Uses the Promise.then() method to chain multiple functions.
 * Multiple handlers can be hooked on the same promise.
 */

final DataflowVariable variable = new DataflowVariable()

final doubler = {it * 2}
final inc = {it + 1}
final dec = {it - 1}

final doubled = variable.then doubler
doubled.then inc then this.&println
doubled.then dec then this.&println

Thread.start {variable << 4}

sleep 1000
