CODEWITHSUNDEEP
scala
Stephen Haberman
Stephen Haberman

Reputation: 1544

Why are parenthesis required for invoking methods with default arguments?

I have a side-effect free method with default arguments that I'd like to invoke without parenthesis, e.g.:

scala> def foo(x: Int = 1) = 42
foo: (x: Int)Int

scala> foo
<console>:9: error: missing arguments for method foo in object $iw;
follow this method with `_' if you want to treat it as a partially applied function
              foo
              ^

scala> foo()
res3: Int = 42

Is this intentional, or just a temporary limitation?

Upvotes: 5

Views: 553

Answers (1)

Rex Kerr
Rex Kerr

Reputation: 167891

This is probably intentional so you don't get parameter blocks disappearing on you:

def foo(x: Int = 2)(y: Int = 4) = x*y

foo(3)    // What does this mean???

Upvotes: 9

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