How to compose to methods, without duplicate input arguments

Question

Suppose I have two methods

scala> def a(a: Int, b: Int, c: Int) : Int = …
a: (a: Int, b: Int, c: Int)Int

scala> def b(i: Int) : Int = …
b: (i: Int)Int         


        

Answer 1

Scalaz defines Functor instances for higher-arity functions, so you can just write

(a _).map(b)