Yeah, sorry, should have provided an example to begin with.

Let's say you have a function "thisFold :: (a -> a -> a) -> [a] -> a"

and it says that the function 'f' passed in must be associative.

Then it goes on to use f in "thisFold f [0,1,2]" like "f (1 (f 0 2))". Obviously f is still associative, but 'thisFold' did not call f 'associatively' on the data. My question is if there is a name for what property this broke by not calling f 'associatively'.

Does that make sense?

On Fri, Oct 23, 2015 at 11:21 AM, Francesco Ariis <fa-ml@ariis.it> wrote:

On Fri, Oct 23, 2015 at 10:26:08AM -0400, Charles Durham wrote:
> Is there a name for a fold that promises to call a function such that only
> an associative function will always return the same result. Or in other
> words, it has the property that it promises to call a function
> "associatively" on a set of data?

I am not sure I am understanding the question correctly. Every Monoid has a
single binary operation which happens to be associative and one of
the basic fold functions has signature

foldMap :: (Foldable t, Monoid m) => (a -> m) -> t a -> m

(which does what you expect). Does that answer your question? If not,
I'd be grateful if you would provide an example.
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