I put up notice of the 8.07 beta on the SIGAPL page: http://sigapl.org/.
On Thu, Aug 23, 2018 at 11:34 PM Devon McCormick <[email protected]> wrote: > It looks like the idea is to defer the evaluation of the name 'windowsize' > until invocation of 'npixels'. So, for instance, if 'windowsize' were a > global variable that was assigned dynamically - at runtime - 'npixels' > takes the current value of that noun at that time? OK, I'm not sure that > differs from how I understand current behavior. > > On Thu, Aug 23, 2018 at 10:22 PM Brian Schott <[email protected]> > 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 <[email protected]> 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 >> > >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > > > -- > > Devon McCormick, CFA > > Quantitative Consultant > > -- Devon McCormick, CFA Quantitative Consultant ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
