Before cons'ing the result of init', you should check whether it's Just or Nothing. What you're doing now is something along the line with 5 : Just 3 -- this won't typecheck.

On Tue, May 12, 2015 at 5:22 PM Roelof Wobben <r.wobben@home.nl> wrote:
Brandon Allbery schreef op 12-5-2015 om 16:16:
On Tue, May 12, 2015 at 10:11 AM, Roelof Wobben <r.wobben@home.nl> wrote:
I do not understand what you are saying to me.

I know that init produces a Maybe [a] . That is why I did put a Just before it.

You are invoking it again though, and using its result as if it produces [a] instead of Maybe [a].

--
brandon s allbery kf8nh                               sine nomine associates
allbery.b@gmail.com                                  ballbery@sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad        http://sinenomine.net


_______________________________________________
Beginners mailing list
Beginners@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners

What is then the right way to do. I still do not understand what you are trying to make clear to me.


Roelof




Avast logo

Dit e-mailbericht is gecontroleerd op virussen met Avast antivirussoftware.
www.avast.com


_______________________________________________
Beginners mailing list
Beginners@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners