Do these experiments help? to =: -.&i.~,]
3 to 5 3 4 5 3 -.&i.~ 5 3 4 5 -.&i. 3 3 4 (i.5)-.(i.3) 3 4 On Sat, Jun 29, 2019 at 2:30 PM Thomas Bulka <thomas.bu...@posteo.de> wrote: > Hello everyone, > > I stumbled across another understanding problem during my efforts to > learn J. I do currently struggle with a sentence defined in the essay "A > Composition on Composition": > > https://code.jsoftware.com/wiki/Fifty_Shades_of_J/Chapter_2 > > In this essay the sentence "to" is defined like this: > > to =: -.&i.~,] > > It works as expected and generates a list of integers from x to y > (dyadic use). I do unterstand (I think) the use of the &-conjunction in > this sentence, but what I don't get is the i.~,]-part. My (obviously > wrong) interpretation goes like this - (s[n] denotes my assumption on > the different steps of evaluation when called with, say, 12 as the > y-parameter): > > s1 =: i.~,] > s2 =: i.~,12 NB. ] denotes the y-parameter > s3 =: i.~12 NB. Now y is raveled > s4 =: 12 i. 12 NB. By using ~ 12 is the x- and y-parameter of i > > The result of the final step would be zero (according to my > understanding), but explicitly calling "s1 12" gives the result 0 12. > Neither do I understand that result, nor do I understand, how this > contributes to the to-sentence defined above. As you can see, I'm > totally lost here and would very much appreciate any explanation on how > to interpret that sentence correctly. > > Please excuse the lengthy description of my misunderstanding, but I > tried to describe my train of thought to make as clear as possible, > where my difficulties in understanding are. > > Thank you very much in advance! > > Kind regards, > > Thomas > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
