[Haskell-cafe] 'Associative' order of calling

[Tom Ellis]

On Fri, Oct 23, 2015 at 12:07:57PM -0400, Charles Durham wrote:
> I can think of a few properties that folds can honor:
> 
> 1. Promises to call f on all data (does not have any guarantees on order)
> 2. Promises to call f on all data in order (like a left fold)
> 3. Promises to call f "associatively" (perhaps can be formalized as an in
> order break down of the data into tree structures)
> 
> I'm assuming at least #1 has a well known name (something completeness?)

2. doesn't have any meaning in a pure language, I think.  What would it mean
to call f on data out of order?