How to skip optional parameters in Scala?

Question

Given the following function with optional parameters:

def foo(a:Int = 1, b:Int = 2, c:Int = 3) ...

I want to keep the default value of a

Answer 1

A solution (far from pretty) could be Currying

You would need to change the method signature a little bit:

// Just for "a" parameter

def foo(a: Int = 1)(b: Int = 2, c: Int = 3)

foo()(2,3)   // 6
foo(1)(2,3)  // 6
foo(2)(2,3)  // 7

For all the parameters:

def foo(a: Int = 1)(b: Int = 2)(c: Int = 3) = a + b + c

foo()()(3)   // 6
foo()(2)(3)  // 6
foo(2)()(3)  // 7
foo(3)()(3)  // 8