I’ll sure take a look. I do think this belongs into any idiomatic J programmer’s toolset. Is there actually a kind of compilation of such a toolset yet?
I found some spread on the phrases & dictionary which both serve a broader need. … but maybe any kind of compilation would grow unfathomably large over time, and everyone should develop and get used to their own set of tools? I’d have thought there are some everyone will benefit from learning and getting used to early on: general patterns which help you rephrase the problem and express a solving algorithm. Did I overlook an existing resource? Any thoughts on whether this would be a good idea? Am 05.02.21 um 15:25 schrieb R.E. Boss: > "It took me a little to understand why this works (I first didn’t get /&.|. > actually works front-to-back) I like this approach." > > > > See the brilliant story in 25. Loopless Code VI: Temporary > Variables<https://www.jsoftware.com/help/jforc/loopless_code_vi_temporary_v.htm> > where I learned it. > > > > > > R.E. Boss > > > > > > -----Original Message----- > From: Programming <programming-boun...@forums.jsoftware.com> On Behalf Of > Hauke Rehr > Sent: vrijdag 5 februari 2021 12:50 > To: programm...@jsoftware.com > Subject: Re: [Jprogramming] Progressive insertion into a string > > > > It took me a little to understand why this works (I first didn’t get /&.|. > actually works front-to-back) I like this approach. I only wonder why you > didn’t > > > > v1a=:4 : '(,`(,`([,x,])@.(={.))@.(2|#@]))/&.|<mailto:2|#@]))/&.|>. y' > > > > and now you see it’s actually > > > > v2a=:4 : '(,`([,x,])@.((={.)*.2|#@]))/&.|<mailto:*.2|#@]))/&.|>. y' > > > > it’s a matter of taste, mostly > > but I think it’s more readable; > > and I developed a disgust to > > @.(0=<test>) and @.(1=<test>) > > just like with some people > > writing nonsense like > > if (myBool == true) > > > > Am 05.02.21 um 12:34 schrieb R.E. Boss: > >> Better is > >> > >> v0a=:4 : '((,`([,x,])@.(={.))`,@.(0=2|#@]))/&.|<mailto:0=2|#@]))/&.|>. y' > >> > >> X v0a L:0 }:data > >> +-------------------+------------------+---------------------+----------------------+ > >> |THEαEQUICKBROWFαFOX|THEαEQUICKBROWFOOX|TαTHEαEQUICKBROWFαFOX|TαTHEαEQUICKBROWFOOαOX| > >> +-------------------+------------------+---------------------+----------------------+ > >> > >> Then > >> > >> soln (-: 'X' v0a L:0 ])&}:data > >> 1 > >> > >> > >> R.E. Boss > >> > >> > >> -----Original Message----- > >> From: Programming >> <programming-boun...@forums.jsoftware.com<mailto:programming-boun...@forums.jsoftware.com>> >> On Behalf > >> Of R.E. Boss > >> Sent: vrijdag 5 februari 2021 10:33 > >> To: programm...@jsoftware.com<mailto:programm...@jsoftware.com> > >> Subject: Re: [Jprogramming] Progressive insertion into a string > >> > >> v0=:((,`([,X,])@.(={.))`,@.(0=2|#@]))/&.|<mailto:0=2|#@]))/&.|>. >> NB. My solution > >> v1=:3 : '(([:*./ ~:/"1)-: ([:I.2=/\{.)-:X I.@:={:)|<mailto:I.@:=%7b:)|>: >> _2[\ y' NB. Check on correctness > >> > >> v0 data5 NB. Does not work on empty string, it's >> OK with me > >> |domain error: v0 > >> | v0 data5 > >> > >> soln (,:~ v0 L:0)&}:data NB. >> data=:data1;data2;data3;data4;data5 > >> >> NB. Same solution with α instead of X > >> +-------------------+------------------+---------------------+----------------------+ > >> |THEαEQUICKBROWFαFOX|THEαEQUICKBROWFOOX|TαTHEαEQUICKBROWFαFOX|TαTHEαEQUICKBROWFOOαOX| > >> +-------------------+------------------+---------------------+----------------------+ > >> |THEXEQUICKBROWFXFOX|THEXEQUICKBROWFOOX|TXTHEXEQUICKBROWFXFOX|TXTHEXEQUICKBROWFOOXOX| > >> +-------------------+------------------+---------------------+----------------------+ > >> > >> v1 S:0 v0 L:0 }:data NB. All (but last) solutions are >> correct > >> 1 1 1 1 > >> > >> > >> R.E. Boss > >> > >> > >> -----Original Message----- > >> From: Programming >> <programming-boun...@forums.jsoftware.com<mailto:programming-boun...@forums.jsoftware.com>> >> On Behalf > >> Of Ric Sherlock > >> Sent: vrijdag 5 februari 2021 02:35 > >> To: Programming JForum >> <programm...@jsoftware.com<mailto:programm...@jsoftware.com>> > >> Subject: Re: [Jprogramming] Progressive insertion into a string > >> > >> Yes as Hauke has previously identified, we need some more test cases to >> fully test whether the spec is correctly implemented or not. > >> I'm thinking that the example outputs you've shown in your email aren't >> correct, but I agree that your approach and Raul's generate different >> solutions for that input and that your one (and Ben's and the current >> solution on Rosetta code) generate the "correct" output as I understand it. >> Here is an updated set of test cases: > >> > >> 'data1 soln1'=: 'THEEQUICKBROWFFOX';'THEXEQUICKBROWFXFOX' > >> 'data2 soln2'=: 'THEEQUICKBROWFOOX';'THEXEQUICKBROWFOOX' > >> 'data3 soln3'=: 'TTHEEQUICKBROWFFOX';'TXTHEXEQUICKBROWFXFOX' > >> 'data4 soln4'=: 'TTHEEQUICKBROWFOOOX';'TXTHEXEQUICKBROWFOOXOX' > >> 'data5 soln5'=: '';'' > >> > >> showDigraphs=: dquote@(',' joinstring _2 <\ ]) > >> > >> dd_bg=: {{ ((+ idx&<)#y) {. y ({. ,'X', }.)~ idx =. >:+: 1 i.~ (=/"1) > >> _2 ]\y }}^:_ > >> dd_md=: dtb@:((] ({.~ , 'X' , }.~) 1 (1 + 2 * i.)~ _2 =/\ ]) {.~ >:@#) > >> ::($:@:,&' ') > >> digra=: * 2 | i.@#<mailto:i.@#> + +/\ > >> dd_rm=: #!.'X'~ 1 j. [: digra # {. }. = }: > >> dd_pj=: ;@:(_2&(,`([,'X',])@.=/each@<\))^:_ > >> > >> Raul's approach looks as though with some more refinement of how to >> calculate which sets of repeat letters need to be split, it should be >> possible. At the moment it produces the incorrect result for data4. > >> > >> ([: showDigraphs dd_rm)&> data1;data2;data3;data4;data5 >> "TH,EX,EQ,UI,CK,BR,OW,FX,FO,X" > >> "TH,EX,EQ,UI,CK,BR,OW,FO,OX" > >> "TX,TH,EX,EQ,UI,CK,BR,OW,FX,FO,X" > >> "TX,TH,EX,EQ,UI,CK,BR,OW,FO,OO,X" > >> "" > >> Iteratively applying Pascal's approaches do result in all digraphs being >> split, but some pairs of letters are split unnecessarily. > >> > >> > >> On Fri, Feb 5, 2021 at 5:04 AM 'Michael Day' via Programming < >> programm...@jsoftware.com<mailto:programm...@jsoftware.com>> wrote: > >> > >>> Just before I venture into updating to the correct beta d... > >>> > >>> Raul's is elegant, single-pass and pretty spare. Here's a verbose, > >>> inelegant, multi-pass one, but it seems to work, except perhaps for > >>> the last example, below. > >>> > >>> I stuck with _2 which means that with odd length strings an error is > >>> thrown on the last pair which is actually not a pair, so needs to be >>> catered for. > >>> > >>> anyway, (it should appear on one line): > >>> dedouble =: dtb@:((] ({.~ , 'X' , }.~) 1 (1 + 2 * i.)~ _2 =/\ ]) > >>> {.~ > >>> >:@#) ::($:@:,&' ') > >>> > >>> dtb is delete trailing blanks, in strings, I think. > >>> > >>> dedouble^:_'THEEQUICKBROWFFOOX' > >>> THEXEQUICKBROWFXFOOX > >>> dedouble^:_'THEEQUICKBROWFOOX' > >>> THEXEQUICKBROWFOOX > >>> > >>> This next example is a bit unlikely to occur, but is this what's required? > >>> dedouble 'THEEQUICKBROWFOOOX' > >>> THEXEQUICKBROWFOOOX > >>> > >>> Raul's version doesn't agree with mine here! Is this result prederred? > >>> rmdedouble 'THEEQUICKBROWFOOOX' > >>> THEXEQUICKBROWFOOOX > >>> > >>> Cheers, > >>> > >>> Mike > >>> > >>> > >>> On 04/02/2021 14:46, Raul Miller wrote: > >>>> Ah, I see it now -- I should have looked closer at your digraphs. > >>>> > >>>> Here's a fixed version: > >>>> > >>>> digra=: * 2 | i.@#<mailto:i.@#> + +/\ > >>>> dedouble=: #!.'X'~ 1 j. [: digra #{.}.=}: > >>>> > >>>> (I could not think of a good name for the "compress out splits of > >>>> non-digraphs" mechanism.) > >>>> > >>>> The moral of the story here is that numeric calculations can often > >>>> replace simple recursive processes. (Because numbers can be defined > >>>> recursively.) > >>>> > >>>> I hope this helps, > >>>> > >>> > >>> > >>> -- > >>> This email has been checked for viruses by Avast antivirus software. > >>> https://www.avast.com/antivirus > >>> > >>> --------------------------------------------------------------------- > >>> - For information about J forums see > >>> http://www.jsoftware.com/forums.htm > >>> > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > >> > > > > -- > > ---------------------- > > mail written using NEO > > neo-layout.org > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- ---------------------- mail written using NEO neo-layout.org ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
