// Using strings makes this a little harder, but it makes
// a lot of the rest of the code easier. This will all go away
// when we can use go/typechecker directly.

// splitFunc splits "func(x,y,z) (a,b,c)" into ["x", "y", "z"] and ["a", "b", "c"].
func splitFunc(s string) (in, out []string) {
	if !strings.HasPrefix(s, "func(") {
		return nil, nil
	}

	i := len("func(") // index of beginning of 'in' arguments
	nparen := 0