Unexpected list non-fusion

wren ng thornton wren at freegeek.org
Mon Dec 19 23:06:18 CET 2011

On 12/15/11 12:38 PM, Simon Peyton-Jones wrote:
> | Am Montag, den 12.12.2011, 15:37 -0500 schrieb wren ng thornton:
> |>  I've noticed that take and filter are good producers (and consumers)
> |>  for list fusion, but takeWhile, drop, and dropWhile are not. Is there
> |>  any reason for this discrepancy?
> |>
> |>  If not, would I need to go through the libraries@ process for fixing
> |>  it, or should I just submit a patch?
> Please just submit a patch.

Will do.

> The latter approach is probably safer.  Follow the pattern for (++).

That's what I was planning on. Replacing unfused calls by non-fusable 
implementations seems to be a performance win in the general case.

Live well,

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