1 Sep
2019
1 Sep
'19
10:22 a.m.
It would also render the combinator useless for its normal purpose.
optional is used mostly to try to run a parser and to either succeed with
its result (wrapped in a Just) or _failing that_ to just return Nothing
and carry on.
For monads like parsec, the first parse is the one that gets returned, so
the definition isn't symmetric in behavior.
-Edward
On Sun, Sep 1, 2019 at 2:28 AM Dannyu NDos
The current 'one or none' definition breaks the order of elements.
It is more Ord-friendly to define it as 'none or one'. _______________________________________________ Libraries mailing list Libraries@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries