specialization using RULES

Simon Peyton-Jones simonpj at microsoft.com
Tue Jun 5 03:49:39 EDT 2007

| The rules do not fire. They only seem to fire if the specialized
| function is called directly, such as
| > doSomethingWith ( zipWith (-) (u :: Vec Three Double) v )

That's probably because to fire
        distance must be inlined
        but sumV and mapV must not
which is obviously a bit delicate.

To do that you need fairly fine grain control over exactly when inlining takes place. That's what the [n] part of an INLINE pragma is for.  Look in GHC.Base for examples.  Don and Duncan are experts.

I wish there was a more robust way to do this.


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