[Haskell-cafe] Re: Why purely in haskell?

[Ketil Malde]

jerzy.karczmarczuk at info.unicaen.fr writes:

> People, you are monsters.

Well, bring on the torches and the pitchforks (although the image in
my mind is more like a mob carrying lenses and bananas).

> no, some users are victims of its success as a formal language, not
> just as a coding tool

I think Haskell's theoretical basis is part of its success as a coding
tool. 

> ... They *want* to have Eq as they imagine the equality,
> including the comparison between incomparable.

In an ideal world, yes, but I think the monster to which you respond
was fairly clear on being 'practical' here?

> The bombing of NaN *might* be a profound compilation option, but for
> people who really do numerical work, this is a blessing NOT to have
> it.

I don't understand this.  Are you worried users will edit the
language pragmas in your code, and complain about NaN errors?

Back when I *was* using the abbreviation FP for 'Floatin Point', I
often got NaNs due to programming errors.  Given the NaN's nature of
contaminating subsequent results, getting an exception at the first
occurrence would aid in tracking it down.

> - Ignoring Int overflow is a cheap way of having `mod` (MAXINT+1). Useful
> for many purposes.

...and ditto for this.  The usefulness of one case in no way justifies
sabotagin all other cases.  I'd wager Ints see wider use in settings
where the silent 'mod' is harmful, than where this effect is desired.
Again, the current behavior causes errors that are very hard to track
down.  IMHO, these are two very different types, and I'm sligtly
baffled that the fact is not reflected in Haskell.

-k
-- 
If I haven't seen further, it is by standing in the footprints of giants