[Haskell-cafe] How to fold on types?

Magicloud Magiclouds magicloud.magiclouds at gmail.com
Tue Dec 25 10:01:49 CET 2012


Forgot to mention, solution without TemplateHaskell.


On Tue, Dec 25, 2012 at 4:59 PM, Magicloud Magiclouds <
magicloud.magiclouds at gmail.com> wrote:

> Say I have things like:
>
> data LongDec = LongDef a b c ... x y z
> values = [ 'a', 'b', 'c', ... 'x', 'y', 'z' ]
>
> Now I want them to be "LongDef 'a' 'b' 'c' ... 'x' 'y' 'z'".
> In form, this is something like folding. But since the type changes, so
> code like following won't work:
>
> foldl (\def value -> def value) LongDef values
>
> Is it possible to do this in some way?
> --
> 竹密岂妨流水过
> 山高哪阻野云飞
>
> And for G+, please use magiclouds#gmail.com.
>



-- 
竹密岂妨流水过
山高哪阻野云飞

And for G+, please use magiclouds#gmail.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20121225/9e0de3f8/attachment.htm>


More information about the Haskell-Cafe mailing list