Is it safe to understand that “[x]” indicates an optional left argument, and is
not part of a the J expression?
> On Aug 24, 2018, at 9:19 AM, Raul Miller <rauldmil...@gmail.com> wrote:
>
> Also, in this example, ‘name’ was meant to represent a pronoun.
>
> Thanks,
>
> —
> Raul
>
>> On Friday, August 24, 2018, Henry Rich <henryhr...@gmail.com> wrote:
>>
>> ".@'name' is a verb. In
>>
>> [x] ".@'name' y
>>
>> y (and x if given) are ignored, and the result is the value of (name) when
>> the verb is executed.
>>
>> This is the same as it used to be, but is now faster.
>>
>> Henry Rich
>>
>>> On 8/23/2018 10:22 PM, Brian Schott wrote:
>>>
>>> Henry, I'm still a little lost.
>>> Is the final `npixels` a (monadic, in this case) verb which will take a
>>> noun argument,
>>> or is the current value of windowsize that noun.
>>>
>>> If the latter, and windowsize is that noun, then what is the value of y in
>>> the original expression `[x] ".@'name' y`?
>>>
>>> If the former (`npixels` is a verb -- and this is the one I'm leaning
>>> toward), then what is the y value that is its argument?
>>>
>>> TIA.
>>>
>>> On Thu, Aug 23, 2018 at 9:41 PM, Henry Rich <henryhr...@gmail.com> wrote:
>>>
>>> Often you need for a verb to refer to the value of a name when the noun is
>>>> executed, rather than when it is defined. So, rather than
>>>>
>>>> npixels =: */ windowsize
>>>>
>>>> which would just be a noun, you write
>>>>
>>>> npixels =: 3 : '*/ windowsize'
>>>>
>>>> to defer taking the value of (windowsize) until (npixels) is executed.
>>>>
>>>> In tacit code, you used to write
>>>>
>>>> npixels =: */ @: ". @ ('windowsize'"_)
>>>>
>>>> to get the same result. Recently the syntax was added to allow
>>>>
>>>> npixels =: */ @: ". @ 'windowsize'
>>>>
>>>> All that still works. But the (".) verb starts the parser and executes
>>>> its y argument as a sentence, with a modest overhead that will matter if
>>>> the verbs have small ranks. Now, you can write
>>>>
>>>> npixels =: */ @: (". @ 'windowsize')
>>>>
>>>> [parentheses important! make sure you see why]. When (npixels) is
>>>> defined, this form will detect that the argument to (".) is a single
>>>> name.
>>>> When (npixels) is executed, the name will be evaluated without going
>>>> through the overhead of starting a sentence.
>>>>
>>>> Henry Rich
>>>>
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