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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