def x = 5

def clos = {println "Hello World!"}
println "Executing the Closure:"
clos()

def sum = {a, b -> println a+b}
sum(4, 5)

def multiplyBy = {num -> num * x}
println multiplyBy(10)

// If you have a Closure that takes a single argument, you may omit the
// parameter definition of the Closure
def printMessage = {println it}
printMessage("hi")

/*
 Groovy can memoize closure results [1][2][3]
*/
def cl = { a, b ->
    sleep(3000)
    a + b
    }
mem = cl.memoize()

def callClosure(a,b) {
    def start = System.currentTimeMillis()
    mem(a,b)
    println "Inputs(a = $a, b = $b)-took ${System.currentTimeMillis() - start}msecs."
}

callClosure(1,2)
callClosure(1,2)
callClosure(1,2)
callClosure(1,2)
callClosure(1,2)
callClosure(1,2)
callClosure(1,2)
callClosure(1,2)
callClosure(1,2)