[Haskell-cafe] Thoughts about redesigning "Num" type class

Brandon Allbery allbery.b at gmail.com
Mon Sep 7 15:28:19 UTC 2015

On Mon, Sep 7, 2015 at 10:08 AM, DreamApart AtHaskells <rnmss.hs at gmail.com>

> We cannot define a (+) alone for a type, so we got many different
> functions
> from different libs, like mappend, mplus, plus, (<+>), (.+.), (+.), which
> all reads
> "plus".

I should mention one other difficulty: MonadPlus and Monoid are not quite
the same thing. mplus and mappend can't really be unified into a single
conceptual structure (mostly because of the Maybe instance).

brandon s allbery kf8nh                               sine nomine associates
allbery.b at gmail.com                                  ballbery at sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad        http://sinenomine.net
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20150907/eb4dd51b/attachment.html>

More information about the Haskell-Cafe mailing list