OK, now we are getting somewhere. I am moving this back to Programming
(because I don't follow Chat). To your points:
1. Often unnecessary: agreed. Fold will not replace u/ etc.:
a. it's too wordy
b. The many ingenious optimizations in u/ will not be provided, at
least not initially
2. If v is an identity, who would need Fold?
a. often true, and they wouldn't use it then
b. but using Z: to control iteration may be convenient
c. Fold allows iteration front-to-back, avoiding &.|.
d. Fold allows specifying an initial value for the first application of u
My expected application for Fold is when u is NOT a primitive. It might
be tacit or explicit, but u is going to be called for each item of y.
Fold gives a terse way to express its computation: the question is
whether those computations are common enough to justify the work. I
agree with Marshall that they are.
I am open to your second-conjunction idea, though I don't see how it
would work. I considered making Fold a set of adverbs using a gerund u
before settling on the proposal as written.
I have expanded the proposal to allow v to be a noun n, which would
execute n&{:: .
Henry Rich
On 3/4/2018 11:56 AM, Raul Miller wrote:
I see where you are going with this now.
And, I do like the thinking. (I'd have to think a bit more, though, to
come up with good examples, for documentation purposes.)
That said, this seems like it would be unnecessary in a good number of
cases - only the "scan-like folds" really make good use of it, and
then only when v is not an identity function.
Perhaps, instead, if we can dip into symbolism a bit more, we could
introduce a second conjunction that modifies folds at the "generate
intermediate result" stage?
[Does this description make sense?]
Thanks,
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