Re: [Haskell-cafe] Contributing to http-conduit

Thanks, looks great! I've merged it into the Github tree. On Sat, Jan 28, 2012 at 8:36 PM, Myles C. Maxfield wrote:

Ah, yes, you're completely right. I completely agree that moving the function into the Maybe monad increases readability. This kind of function is what the Maybe monad was designed for.

Here is a revised patch.

On Sat, Jan 28, 2012 at 8:28 AM, Michael Snoyman wrote:

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On Sat, Jan 28, 2012 at 1:20 AM, Myles C. Maxfield wrote:

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the fromJust should never fail, beceause of the guard statement:

    | 300 <= code && code < 400 && isJust l'' && isJust l' = Just $ req

Because of the order of the && operators, it will only evaluate fromJust after it makes sure that the argument isJust. That function in particular shouldn't throw any exceptions - it should only return Nothing.

Knowing that, I don't quite think I understand what your concern is. Can you elaborate?

You're right, but I had to squint really hard to prove to myself that you're right. That's the kind of code that could easily be broken in future updates by an unwitting maintainer (e.g., me). To protect the world from me, I'd prefer if the code didn't have the fromJust. This might be a good place to leverage the Monad instance of Maybe.

Michael