Re: [Haskell-beginners] How to show a record

17 Aug 2014


      In that case, can you elaborate please? I don't see how this is different
to making the record itself an instance if Show.

Best wishes,
Karolis Velicka
On 17 Aug 2014 10:44, "martin"  wrote:
...
Right, but this is merely a coincidence.
What I wanted is a way to show a value of a record, where all fields are
instances of Show.
Haskell itself is able to do this (and it even figures out the accessors,
which I am not even asking for).
...
Your particular types do not require your annoying repetition beyond
[ show . pType, accepts, produces, workarea] with 1st show = (:[])
On Sat, Aug 16, 2014 at 10:45 AM, martin mailto:martin.drautzburg@web.de> wrote:
Hello all,
I have a record type like this
data Payload = Pl {
                        pType    :: Char,
                        accepts  :: String,
                        produces :: String,
                        workarea :: String} deriving (Eq)
an I want to write my own show function. I ended up with somethink
Am 08/16/2014 12:39 PM, schrieb Roman Czyborra:
like this
...
show pl = concatMap ( $ pl) [show . pType, show . accepts,
show . produces, show . workarea]
...
That repetition of "show ." annoys me, but of course without it the
elements of that list would have different types. Is
...
there a way around it and how does haskell itself manage to show
records?
...
_______________________________________________
    Beginners mailing list
    Beginners@haskell.org mailto:Beginners@haskell.org
    http://www.haskell.org/mailman/listinfo/beginners
_______________________________________________
Beginners mailing list
Beginners@haskell.org
http://www.haskell.org/mailman/listinfo/beginners
_______________________________________________
Beginners mailing list
Beginners@haskell.org
http://www.haskell.org/mailman/listinfo/beginners