Groovy: Multi threaded producer consumer program

import java.util.concurrent.BlockingQueue
import java.util.concurrent.LinkedBlockingQueue

BlockingQueue queue = new LinkedBlockingQueue();

Thread.start('Producer') {
    10.times {
        println(Thread.currentThread().name + " adding $it")
        queue << it
        sleep(100)
    }
}

Thread.start('Consumer') {
    for(i in 0..9){
        sleep(200)
        print(Thread.currentThread().name)
        println("consuming ${queue.take()}")
    }
}

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Groovy: Closure Composition

Closure composition corresponds to the concept of function composition, that is to say creating a new function by composing two or more functions (chaining calls), as illustrated in this example:

def plus2  = { it + 2 }
def times3 = { it * 3 }

def times3plus2 = plus2 << times3
assert times3plus2(3) == 11
assert times3plus2(4) == plus2(times3(4))

def plus2times3 = times3 << plus2
assert plus2times3(3) == 15
assert plus2times3(5) == times3(plus2(5))

// reverse composition
assert times3plus2(3) == (times3 >> plus2)(3)