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@akhikhl
Created September 4, 2013 10:32
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switch statement and closure comprehension
def isGreaterThan(a, b) { a > b }
def isGreaterThan(b) {
return { a -> isGreaterThan(a, b) }
}
def isLessThan(a, b) { a < b }
def isLessThan(b) {
return { a -> isLessThan(a, b) }
}
def x = 5
def y = 6
switch(x) {
case isGreaterThan(y):
println "$x is greater than $y"
break
case isLessThan(y):
println "$x is less than $y"
break
default:
println "$x equals $y"
}
@akhikhl
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akhikhl commented Sep 4, 2013

The trick here is that single-argument versions of IsGreaterThan, IsLessThan return closures. Switch-statement “understands” closures: it passes it’s argument (x in our case) as a parameter to the closure and expects boolean result being returned from the closure.Same thing can be done via function currying, but it looks not so nice, as with function overload.

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