[Haskell-cafe] map (-2) [1..5]

[John Meacham]

On Fri, Aug 18, 2006 at 12:20:54AM +0100, Brian Hulley wrote:
>    data Integer = ... | -1 | 0 | 1 | ...
> 
> tells me that the negative and positive integers are on an equal footing.
> 
> Ie the language is sending out a "mixed message" about the integers, which 
> is confusing.

Not only that but there is a run-time penalty for every polymorphic
negattive literal!

-3 desugars to negate (fromInteger 3)  rather than (fromInteger -3) so
you end up having to do 2 dictionary lookups (one for fromInteger, one
for negate) and indirect function calls rather than just the one.

        John


-- 
John Meacham - ⑆repetae.net⑆john⑈