def from_prototype(prototype)
      prototype.split(/, */).each do |arg|
        if arg =~ /:/
          arg = arg.split(":")
          name, sig = arg
        else
          sig = arg
        end
        add_fparam(name, sig)
      end
      self
    end
def from_prototype(prototype)
      prototype.split(/, */).each do |arg|
        if arg =~ /:/
          arg = arg.split(":")
          name, sig = arg
        else
          sig = arg
        end
        add_fparam(name, sig)
      end
      self
    end
Add parameter types based on the given _prototype_.