[Haskell-beginners] (SPAM 3)Re: (SPAM 3)Re: database, list result, extraction and conversion

Francesco Ariis fa-ml at ariis.it
Fri Dec 7 08:59:56 UTC 2018


On Fri, Dec 07, 2018 at 09:44:03AM +0100, Damien Mattei wrote:
>  let noBD = fromOnly (Prelude.head bd_rows)
> 
> give me a solution, but i'm still searching a solution with map has in a
> list there could be more than one result...

So put this in your code

    let noBD = map _ bd_rows

`_` will tell the compiler "tell me which type goes there". Then you
can choose the appropriate function!


More information about the Beginners mailing list