Slime wrote:
>> Er, no. Just tried it with the release version. The numbers are a fraction 
>> of a second slower still. Either way, two equivilent formulations of the 
>> program have wildly different runtimes.
> 
> What's the difference between them?

One relies on automatic list fusion, the other is hand-fused. It turns 
out GHC doesn't automatically fuse left folds. Since the entire program 
is a left fold, I guess that'll be the problem then...

If my assumption that all list operations do get fused had been correct, 
the two programs *would* be almost completely equivilent. (One with more 
overloading than the other, possibly contributing to a few percent 
overhead.)

This is what happens when you *assume* you know what you're talking 
about; you get caught out.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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