Break

Break

[Andrew Conway]

Dear Caml community,

I would like to suggest a "new" standard exception: Pervasives.Break.

I frequently wish to break out of a "for" loop, when looking for
something, and want some exception designed for that purpose. Having
a standard one would make programs more standard, and reduce proliferation
of custom Break type exceptions.


[ En mauvais francais ]

Chers Utilisateurs de Caml,

Je voudrais vous proposer un exception nouveau : Pervasives.break.

Souvent je veux quitter "for ... do .. done", quand je cherche quelque
chose, et il faut definer un exception neuveau. S'il y avait un
exception commun, les logiciels serait plus facile a comprendre, et
il n'y aurait pas tellement des exceptions comme A.Break, B.Break,...

Amities,

Andrew.

Re: Break

[Pierre Weis]

> I would like to suggest a "new" standard exception: Pervasives.Break.

There already exists a Break exception:

# Sys.Break;;
- : exn = Break

It has another meaning, snce it is used to signal an interrupt (^C in
general under Unix).

# raise Sys.Break;;
Interrupted.

Ther is no problem to use it to exit from loops, but it could be a bit
confusing. Thus, there also exists an exception devoted to premature
exits from loops:

# Pervasives.Exit;;
- : exn = Exit

you should raise the Exit exception when you want a premature end of
loop. (This is also true for Caml Light.)

> [ En mauvais francais ]
> 
> Chers Utilisateurs de Caml,
> 
> Je voudrais vous proposer un exception nouveau : Pervasives.break.

Elle existe de'ja`: c'est l'exception Pervasives.Exit en Objective
Caml ou Exit en Caml Light. L'exception Sys.Break (ou sys__Break) est
consacre'e a` signaler les interruption venant du syste`me
d'exploitation (en ge'ne'ral appui sur ^C sous Unix).

Best regards,

Pierre Weis

INRIA, Projet Cristal, Pierre.Weis@inria.fr, http://pauillac.inria.fr/~weis