I was thinking of `. as a modifier for / /\. and a few other adverb
sequences, to provide the initial value (which matters when it would
be a different shape, or type, from the sequences being operated on.
Taking this the next step, let's maybe use O: to introduce v - O:
would be similar to @: but would be for use in folds. v O:u/\.`. would
be my alternate syntax proposal for u F::v
I'm not sure, yet, that this is better, but I'd like to at least talk
through the issues.
Well, ok, it *is* better in the sense that my proposal introduces less
new vocabulary, and takes advantage of visual similarity in a way that
the F. F.. F.: F: F:. F:: proposal does not. But the specific details
might be too gimmicky - for example, it might be better to instead
have a `. and a `.: for example, where the `. is an adverb and the `.:
is a conjunction (whose right argument is v).
Thoughts?
Thanks,
--
Raul
On Sun, Mar 4, 2018 at 12:38 PM, Henry Rich <henryhr...@gmail.com> wrote:
> 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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