Re: predicates

[Emanuel Berg]

"Pascal J. Bourguignon" <pjb@informatimago.com>
writes:

> One notable predicate that returns something useful
> not obtainable otherwise, is:
>
>    (digit-char-p ?4) --> 4
>
> You could use:
>
>     (ignore-errors (parse-integer (string ?4))) --> 4
>
> but parse-integer uses digit-char-p which is the
> more fundamental operation.

And this is what I love with Lisp. There is an endless
world to (re)discover. As soon as you reach one level,
you realize there is another which you didn't
know existed.

-- 
underground experts united
http://user.it.uu.se/~embe8573