[Haskell-cafe] Re: Profiling nested case

Mitar wrote:

On Fri, Jul 18, 2008 at 3:54 PM, Chaddaï Fouché wrote:

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So that I can easily change the type everywhere. But it would be much nicer to write:

data Quaternion a = Q !a !a !a !a deriving (Eq,Show)

Only the performance of Num instance functions of Quaternion is then quite worse.

You can probably use a specialization pragma to get around that.

But why is this not automatic? If I use Quaternions of only one type in the whole program then why it does not make specialized version for it? At least with -O2 switch.

You could try jhc: it does whole program optimization. Ghc compiles each module separately. Cheers Ben