CODEWITHSUNDEEP
scala
Pavel
Pavel

Reputation: 1539

scala: enforce immutable type in closure

Simple question one more time.

How can I specify in function/closure below that [more] should come from immutable type?

Other wise I am having this side effect as below!

Thanks

var more  = 3

def increase[T: Numeric](x: T): T = implicitly[Numeric[T]].plus(x, more.asInstanceOf[T])

val inc =  increase[Int] _

more = 10

println( inc(5) )

Upvotes: 2

Views: 79

Answers (1)

Tzach Zohar
Tzach Zohar

Reputation: 37832

Not sure that's what you're looking for, but if you want to ensure the value used by the function doesn't change after a certain point, you can add it as a separate argument list, and partially-apply the function with its value:

var more  = 3

def increase[T: Numeric](base: T)(x: T): T = implicitly[Numeric[T]].plus(x, base)

val inc =  increase[Int](more) _

more = 10

println( inc(5) ) // prints 8, as expected

Upvotes: 5

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