14 Aug
2011
14 Aug
'11
8:53 p.m.
On Mon, Aug 15, 2011 at 7:12 AM, Paterson, Ross
Sebastian Fischer writes:
+1 for adding Monoid and Semiring earlier rather than later which would allow me to drop my own definitions for semirings in my libraries for regular expression matching and parallel programming.
I see your versions of + and * are infixr rather than infixl. Is that important?
I copied fixities from the Prelude [1] for + and * but don't know why they are infixl there. I think, I even prefer right associative operators. For example, for the free semiring "bag of lists", + for bag union resembles ++ which is right associative. Best regards, Sebastian [1] http://www.haskell.org/onlinereport/standard-prelude.html