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

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.

Jay

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
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-- 
Jay McCarthy <jay at cs.byu.edu>
Assistant Professor / Brigham Young University
http://faculty.cs.byu.edu/~jay

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