What would be "the next new value of x"? Can x be a list, and _1's get
chopped off until another x comes up?
On Wednesday, August 28, 2019, 08:42:42 p.m. EDT, Henry Rich
<[email protected]> wrote:
In the description of Z:, x refers to the left argument of Z:, not of
any fold it is running in.
Henry Rich
On 8/28/2019 7:43 PM, 'Pascal Jasmin' via Beta wrote:
>
> Thank you Raul, that model is intuitive
>
> ([ [ _1 Z: 5 < -) F:. ] p: i.20
>
> 3 5 7 11 13 17 19 23
>
> its not obvious why this terminates. _1&Z: description makes reference to x
> even if it doesn't exist ("next new value of x" makes no sense if y is the
> one with items) . I thought it would do something similar to the following.
>
> ([ [ 0 Z: 5 < -) F:. ] p: i.20
>
> 3 5 7 11 13 17 19 23 31 41 43 47 61 71
>
> ([ [ 0 Z: 5 >: -) F:. ] p: i.20
>
> 29 37 53 59 67
>
>
>
>
>
>
> On Wednesday, August 28, 2019, 06:07:25 p.m. EDT, Henry Rich
> <[email protected]> wrote:
>
>
>
>
>
> Your imagination about how to use this matches mine.
>
> But please suggest improvements as they occur to you! This is being put
> out as a J addon right now, so it will be easy to change as we gain
> experience. In a few months, when we deem the design solid, the
> implementation will be put into C and frozen there.
>
> Henry Rich
>
> On 8/28/2019 5:59 PM, Raul Miller wrote:
>> On Tue, Aug 27, 2019 at 10:47 PM 'Pascal Jasmin' via Beta
>> <[email protected]> wrote:
>>> I think all references for Z: should refer to u verb? Would Z: ever be
>>> called in v verb? _1&Z: makes no sense.
>>> As a simple example, find first prime whose next prime is greater than 5
>>> higher?
>>>
>>> [`(_2 Z: 1:)@.(5 < -) F.. ] p: i.20
>>> 23
>> Is this equivalence worth noting?
>>
>> ([ [ _2 Z: 5 < -) F.. ] p: i.20
>> 23
>>
>> The right argument to Z: is a on/off control value -- 0 means Z: does
>> nothing that time.
>>
>> With this fold implementation, I anticipate seeing constructs like:
>> f [ opcode Z: test
>>
>>> How might you get the first prime whose previous neighbour is less than 5
>>> higher? (29)
>> Presumably, you were hinting at a variation on this:
>>
>> ([ [ 1 Z: 5 < -) F.. ] p: i.20
>> 29
>>
>> Thanks,
>>
>
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