I thought of something else you can do
(sequence->list
(in-generator
(for ([e (in-list l)])
(if (f e)
(if ...
(begin (yield 1) (yield 2))
(yield 3))
(void)))))
I've done that a few times
Jay
2011/4/15 Jay McCarthy <[email protected]>:
> 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 <[email protected]>:
>> 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 <[email protected]>
> Assistant Professor / Brigham Young University
> http://faculty.cs.byu.edu/~jay
>
> "The glory of God is Intelligence" - D&C 93
>
--
Jay McCarthy <[email protected]>
Assistant Professor / Brigham Young University
http://faculty.cs.byu.edu/~jay
"The glory of God is Intelligence" - D&C 93
_________________________________________________
For list-related administrative tasks:
http://lists.racket-lang.org/listinfo/users
