From: George Ogata <g_ogata@...>
Date: 2004-03-21T00:24:37+09:00
Subject: Re: `#catch'ing many symbols

"Robert Klemme" <bob.news@gmx.net> writes:

> Well, that's not too difficult, since one often has an entry method to
> recursion:
>
> def enter(*args)
>   catch :quit do
>     catch :done do
>       recur_impl(*args)
>     end
>   end
> end
>
> def recur(*args)
>   catch :done do
>     recur_impl(*args)
>   end
> end
>
> def recur_impl(*args)
>   if ...
>      recur x
>   else
>       ...
>   end
> end

It's not a case of it being difficult, I just think it's more
naturally expressed the other way.  Each to their own, I suppose.

>> In my case, I have a stackable command interpreter interface
>> ("stackable" in the sense that you can recursively invoke one while
>> one is running, like the way you sometimes nest shells).  One command
>> exits just the topmost layer to return to the one below.  Another
>> exits the whole stack.
>
> Is that really a case for recursion?

I think it's easiest done so, yes.

> As I said, I don't think it's a reasonable extension...

K.