Re: [Caml-list] Re: Help me find this pdf

[Christophe Raffalli <Christophe.Raffalli@univ-savoie.fr>]

[-- Attachment #1.1: Type: text/plain, Size: 1376 bytes --]

Luc Maranget a écrit :
>> You mean that if I write (I use OCaml syntax)
>>
>> match p, q with
>> | (true, true) -> A
>> | _ -> B
>>
>> Haskell will first check if (p is evaluated and false) or (q is evaluated and false)
>> and then, if it is not the case will evaluate p, and finally if p is true it will evaluate q ?
>>
>>     
>
> Haskell has left-to-right semantics for PM. Basically this is expressed
> by PM compilation.
>   
And this is not optimal (I was answering the sentence "Haskell does it
right"). In fact, there is no optimal
way of doing pattern matching in lazy languages (with deep pattern)
because the language can not
decide what is best to evaluate. Certainly left to right is a
reasonnable choice,
but letting the programmer choose (or even forcing him to choose has in
OCaml) is
a good choice (I think better).

-- 
Christophe Raffalli
Universite de Savoie
Batiment Le Chablais, bureau 21
73376 Le Bourget-du-Lac Cedex

tel: (33) 4 79 75 81 03
fax: (33) 4 79 75 87 42
mail: Christophe.Raffalli@univ-savoie.fr
www: http://www.lama.univ-savoie.fr/~RAFFALLI
---------------------------------------------
IMPORTANT: this mail is signed using PGP/MIME
At least Enigmail/Mozilla, mutt or evolution 
can check this signature. The public key is
stored on www.keyserver.net
---------------------------------------------


[-- Attachment #1.2: Christophe.Raffalli.vcf --]
[-- Type: text/x-vcard, Size: 310 bytes --]

begin:vcard
fn:Christophe Raffalli
n:Raffalli;Christophe
org:LAMA (UMR 5127)
email;internet:christophe.raffalli@univ-savoie.fr
title;quoted-printable:Ma=C3=AEtre de conf=C3=A9rences
tel;work:+33 4 79 75 81 03
note:http://www.lama.univ-savoie.fr/~raffalli
x-mozilla-html:TRUE
version:2.1
end:vcard


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 249 bytes --]