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

[Jon Fairbairn]

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.


-- 
Jón Fairbairn                                 Jon.Fairbairn at cl.cam.ac.uk
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html  (updated 2009-01-31)