[Haskell-beginners] Looking for alternative practices suggestions

[Michael Litchard]

Thanks Brent. I just may use a Reader monad in version 2 for the sake
of learning how to do it.

On Fri, Aug 5, 2011 at 6:51 AM, Brent Yorgey <byorgey at seas.upenn.edu> wrote:
> On Thu, Aug 04, 2011 at 02:53:34PM -0700, Michael Litchard wrote:
>> I'm finding that in more than one instance I pass a data structure to
>> a function, simply so that I can pass it to it's helper function. It
>> bugs me that I'm passing a value that isn't being used directly. This
>> seems wrong. Example: I have a "data URLSequence" that contains a way
>> to calculate the ip address of a URL. This gets passed to a helper
>> function that generates a particular URL, which then populates the
>> URLSequence. Is there a standard practice to avoid what I am talking
>> about? Or is this normal and I should accept it?
>
> Others have answered the question in a way that seems to address your
> situation well.  However, I thought I would also mention that in the
> case where there is a single piece of read-only data that needs to be
> annoyingly threaded through large parts of your code, you can use the
> Reader monad to make the threading implicit.  But this solution is too
> heavyweight for some situations since it does require changing the
> code to use a monadic style.
>
> -Brent
>
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