Discussion of proposal 2015-005 (Addition of Fn module).

[rossberg-old]

This issue is for discussion of proposal 2015-005 (Addition of Fn module).

[JohnReppy]

Are you proposing that General.o be deprecated or just that Fn.o and General.o be two different bindings for the composition function?

Also, I'm not convinced that repeat belongs in this module. I imagine that a more complete set of iteration combinators would make a useful addition to the Basis.

[rossberg]

I'd be fine with deprecating General.o, but would consider that a separate proposal. Short of that, yes, they would bind the same function.

I'm open regarding the exact set of combinators in this module. I care most about the first 2. Would repeat really fit an iteration module, though? It doesn't give you access to the iteration variable at all, it is more like o to the n-th.

[mn200]

A nice abbreviation for curry op= (equal, say) would be nice.

[JohnReppy]

I like the idea of including shorthand for curry op= (and probably curry op<> too).

[igstan]

Does it make sense to add a reverse application operator named |> to Fn?

val |> : 'a * ('a -> 'b) -> 'b = fn (a, f) => f a;

This is probably less useful than adding it to Pervasives, because one would also have to declare the precedence and associativity when opening the structure. Nevertheless, I found it useful in my projects. Much more useful than o anyway.