From: Hal Fulton <hal9000@...>
Date: 2006-02-08T10:05:27+09:00
Subject: Re: lazy evaluation?

Martin DeMello wrote:
> vidar.hokstad@gmail.com <vidar.hokstad@gmail.com> wrote:
> 
>>It's your assumption of where the "retry" restarts execution that's
>>wrong... Essentially the retry in "repeat" will restart execution right
>>before the call to repeat, not at the start of the "repeat" method,
>>thus evaluating the arguments again.
>>
>>You can see that by changing your code so that there's an observable
>>side effect of the reevaluation:
> 
> 
> This seems wrong to me, for precisely the reason you cite - it means
> that I can never do something like object.foo(ary.pop), without
> physically reading the source of #foo to see whether it calls retry
> anywhere.

I never thought of it that way. I always thought of it in the context
of reevaluating an expression whose value might have changed -- but
side effects never occurred to me.


Hal