#doOnlyOnce (was Re: [BUG] '3 + 4' crashes Squeak ...)

PhiHo Hoang phiho.hoang at home.com
Fri Oct 5 01:43:32 UTC 2001


Hi Doug,

> [self halt] doOnlyOnce.

    This is neat, I like it. But is it sementically the same as:

    self doOnlyOnce: [self halt].

    If you have a change set, I volunteer to test it ;-)

    Cheers,

    PhiHo


----- Original Message -----
From: "Doug Way" <dway at riskmetrics.com>
To: <squeak-dev at lists.squeakfoundation.org>
Sent: Thursday, October 04, 2001 8:06 PM
Subject: #doOnlyOnce (was Re: [BUG] '3 + 4' crashes Squeak ...)


>
> "Randal L. Schwartz" wrote:
> >
> > In that case, what you really want is a DoOnlyOnce class subclassed
> > from Object, as a singleton, with the protocol:
> >
> >         DoOnlyOnce arm "in a do-it"
> >
> >         ...
> >
> >         DoOnlyOnce once: [self halt] "in a method"
>
> Looking at this (and our earlier exchanges), and noticing that we're
trying to find a place to hang a method which is always passed a block...
now I'm thinking that the best way to handle it would be to add an instance
method to BlockContext, so that the usage becomes simply:
>
> [self halt] doOnlyOnce.
>
> (Or, in keeping with other BlockContext methods, maybe #valueOnlyOnce.
But somehow #doOnlyOnce seems better.)
>
> The #rearmOneShot method would become a class method for BlockContext.
>
> > ...
> > I know.  "Changesets welcome" :)
>
> Yes.  Not that it would be hard to make this changeset, but I'd rather
wait until the violent disagreement subsides first... :)
>
> - Doug Way
>   dway at riskmetrics.com
>
>





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