From: Dossy <dossy@...>
Date: 2002-07-10T01:10:54+09:00
Subject: Re: for ... else ... end

On 2002.07.09, Sean Russell <ser@germane-software.com> wrote:
> Yukihiro Matsumoto wrote:
> 
> > But I don't feel "for .. else" is intuitive.  The "else" seem like
> > indentation mistake rather than loop termination hook.  Maybe there
> > can be a more suitable keyword.
> 
> Here are the suggestions, so far:
> 
>         else
>         ensure
>         finally

I'd add "afterwards" as the most logical English keyword:

for ...
    # do stuff
afterwards
    # do stuff
end

But then it's not clear if afterwards gets done always, or only
if the loop iterates completely.

I don't think "ensure" should be used, because that seems like
it should always be executed upon exiting the iterator regardless
of if it completely iterated or was broken out of.

I think the "else" syntax for indicating code that should be
executed when the iterator is empty is cool, but unnecessary
as there are other ways of implementing the same behavior just
as clearly.  I definitely think the choice of "else" in Python
was a poor choice as you're really not doing "this or else that"
with regard to the iterator.

I think "then" might be the more appropriate keyword:

for ...
    # do stuff
then
    # do stuff when finished iterating
end

Breaking out of the iterator breaks out of the whole construct,
skipping the "then" clause code.

-- Dossy

-- 
Dossy Shiobara                       mail: dossy@panoptic.com 
Panoptic Computer Network             web: http://www.panoptic.com/ 
  "He realized the fastest way to change is to laugh at your own
    folly -- then you can let go and quickly move on." (p. 70)