Re: [Haskell-cafe] Monad laws in presence of bottoms

21 Feb 2012


      * Sebastian Fischer  [2012-02-21 00:28:13+0100]
...
On Mon, Feb 20, 2012 at 7:42 PM, Roman Cheplyaka  wrote:
...
Is there any other interpretation in which the Reader monad obeys the
laws?
If "selective strictness" (the  seq  combinator) would exclude function
types, the difference between  undefined  and  \_ -> undefined  could not
be observed. This reminds me of the different language levels used by the
free theorem generator [1] and the discussions whether  seq  should have a
type-class constraint..
It's not just about functions. The same holds for the lazy Writer monad,
for instance.

-- 
Roman I. Cheplyaka :: http://ro-che.info/