[Haskell-cafe] Re: Type-level lambdas in Haskell? ( was Multiparameter class error)

Alfonso Acosta alfonso.acosta at gmail.com
Wed Feb 21 23:23:07 EST 2007

On 2/22/07, oleg at pobox.com <oleg at pobox.com> wrote:
> First of all, the design already exhibits the problem:


> The reason is that [..]
> the function delaySY is declared *fully* polymorphic over 'a' -- there
> are no constraints on a and no restrictions. However,
> > delaySY :: HDPrimType a => a -> HDSignal a -> HDSignal a

I didn't even notice this problem.

> I'm not certain if there is a compelling reason to place mapSY,
> delaySY and zipWithSY in the same class

There's not such a reason, I was just stupid enough to overlook that
splitting the class would do the trick.

> If not, the following is the solution to the problem.

Certainly :)

Even if your solution doesn't look really elegant, it's the perfect
workaround ... as it's the only one I have. Thanks a lot.

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