On Thu, 2009-09-17 at 14:37 +0100, Ross Paterson wrote:
This proposal seems to have got stuck. Everyone wants an infix operator, but we can't agree what it should be.
I prefer using a new operator instead of generalizing ++ (or +, *, && or ||), because I think that a monoid operation is so abstract that it needs a name that doesn't suggest one of the special cases. (I like <>)
Nice. For some reason I much prefer a symbol like <> to one like +>. I want to say that it's because it looks symmetric, though of course mappend, ++ are associative not symmetric, so it's not a very good argument. But I still like it! :-) So I guess we should adjust the proposal, or make a new one. * Suggest the name <> (which so far seems to have popular support) * Get rid of the suggestion for a reverse mappend operator * As Krasimir says, include in the proposal that we would deal with the existing libraries that use a local <> for their mappend operator (at least Text.PrettyPrint). One thing we've not mentioned much is operator precedence. Existing uses: infixr 5 Data.Sequence.>< infixl 6 Text.PrettyPrint.<> Existing proposal about (+>) infixl 4 +> Duncan