[Haskell-cafe] Re: ANNOUNCE: Utrecht Haskell Compiler (UHC) -- first release

Miguel Mitrofanov miguelimo38 at yandex.ru
Mon Apr 20 06:12:14 EDT 2009

I disagree. First of all, UHC states explicitly that some features are not supported (and probably never would be). Secondly, it seems like 
almost nobody uses (n+k)-patterns, and when they are used, they make the code less readable; so it's good NOT to support them, in order to make 
programmers avoid them as much as possible. I don't think #ifdef's would be really "all over the place"; it's more likely that a minor 
refactoring would take place so that (n+k)-patterns would disappear.

Jon Fairbairn wrote on 20.04.2009 13:59:
> Achim Schneider <barsoap at web.de> writes:
>> Jon Fairbairn <jon.fairbairn at cl.cam.ac.uk> wrote:
>>> atze at cs.uu.nl writes:
>>>> 	    Utrecht Haskell Compiler -- first release, version 1.0.0
>>>> 	    ========================================================
>>>> The UHC team is happy to announce the first public release of the
>>>> Utrecht Haskell Compiler (UHC). UHC supports almost all Haskell98
>>>> features
>>> Why? Is there something about Haskell 98 that's hard to
>>> implement?
>> Insanity. I doubt anyone is going to miss n+k patterns:
> That (taken with the followup from Richard O'Keefe saying he
> does use them) underlines my point, really. What follows is
> specific to Haskell, but the general point applies to most
> languages I've encountered.
> I have no love for n+k patterns, but they are part of
> Haskell98 -- and were the subject of protracted arguments
> for and against them before the Report was finished (I was
> against them, if I remember correctly). Any implementation
> claiming to be of Haskell98 should have them, whether or not
> the implementor likes them, because otherwise someone will
> come along with a valid Haskell98 programme and it won't
> compile, so they'll have to hack it around. This sort of
> thing (and resulting #ifdef all over the place) wastes far
> more programmer time in the end (assuming the compiler
> becomes popular) than it would take to implement the
> feature.
> It's not an implementor's place to make such decisions --
> they can legitimately say "this feature sucks" and tell the
> next Haskell committee so. If they care enough about it,
> they can lobby or get on that next committee, but the
> arguments for n+k patterns /in Haskell98/ were done long
> ago.

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