Re: cond and match

[Hannah Schroeter]

Hello!

On Sun, Dec 09, 2001 at 01:07:08PM +, Marcin 'Qrczak' Kowalczyk wrote:
 Fri, 7 Dec 2001 17:12:52 -0500 (EST), David Feuer [EMAIL PROTECTED] pisze:

  I'm wondering why Haskell doesn't support Scheme-like cond statements
  or a pattern matching predicate.

 I agree that both constructs make sense. The main objective is probably
 that the syntax is already quite rich and this would be another thing
 to learn and implement.

As well, these constructs would reserve two more identifiers and so
break quite some existing programs. I could expect that especially
match could be used sometimes, like
let match = search foo bar in
use match somehow

Kind regards,

Hannah.

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Re: cond and match

[Marcin 'Qrczak' Kowalczyk]

Fri, 7 Dec 2001 17:12:52 -0500 (EST), David Feuer [EMAIL PROTECTED] pisze:

 I'm wondering why Haskell doesn't support Scheme-like cond statements
 or a pattern matching predicate.

I agree that both constructs make sense. The main objective is probably
that the syntax is already quite rich and this would be another thing
to learn and implement.

-- 
 __(  Marcin Kowalczyk * [EMAIL PROTECTED] http://qrczak.ids.net.pl/
 \__/
  ^^
QRCZAK


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cond and match

[David Feuer]

I'm wondering why Haskell doesn't support Scheme-like cond statements or a
pattern matching predicate.

cond
   c1-v1
   c2-v2
   

or possibly
cond
   | c1 - v1
   | c2 - v2
   ...

would translate as

case () of
_ | c1 - v1
  | c2 - v2
  | 

also, it seems that a match predicate could occasionally be useful

match p v would mean
case v of
   p - True
   _ - False


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