Question

I have a method that looks like

def SomeMethod (*args)
     m = if args.length > 0 then 
            self.method(:method1) 
         else 
            self.method(:method2)
         end
     m.call ... #need to either pipe all arguments aside from the first
                #and in other cases substitute the first argument
end

The actual structure is a litle more complex where the method to be called is from different instances and in some cases I’d have to pipe all arguments lest the first and in other cases I’d have to substitute the first argument with another value

Answer 1

You can use the so called splat operator * to expand an array into an argument list:

# Call with all but the first element
m.call *args[1..-1]

# Replace first element
m.call *args[1..-1].unshift(newarg)

What does the (unary) * operator do in this Ruby code?
Weird multiplicator operator behavior in a two arrays to hash combination