[racket] generating 0 or more than 1 additions in the body of for/list, for/vector, for/hash

From: Jay McCarthy (jay.mccarthy at gmail.com)
Date: Fri Apr 15 15:15:50 EDT 2011

I turn it into a for/fold or figure how to put the cases I don't want
in the list as #:when for clauses. I think this is a lame solution. I
almost want a C-like "continue" function. Returning an option type
seems like overkill.


2011/4/15 harsha reddy <wembdnow at gmail.com>:
> When using  the various versions of for like for/list; I often encounter
> situations where the body must not add any value to put into the generated
> list  (useful when one needs to filter and map simultaneously) or must
> generate more than value. I guess the way to do this would be to treat the
> result of the body as a list of additions and then concatenate all these
> lists. Something similar would be needed for for for/hash(taking care of the
> multiple values issue),for/and, for/vector etc.
>   I just wanted to know, because this seems like a common enough situation,
> if there are some standard commands or libraries which implement the
> modified versions of these commands.
> thanks,
> Harsha
> _________________________________________________
>  For list-related administrative tasks:
>  http://lists.racket-lang.org/listinfo/users

Jay McCarthy <jay at cs.byu.edu>
Assistant Professor / Brigham Young University

"The glory of God is Intelligence" - D&C 93

Posted on the users mailing list.