[Jprogramming] Consecutive substrings (was Quora problem)

[Ric Sherlock]

Awesome thanks Henry!
Especially the #\

On Fri, 25 Oct 2019, 22:19 Henry Rich, <henryhrich at gmail.com> wrote:

> Some fine points of interpreter use:
>
>  >:@i.@#
>
> is the same as
>
> #\
>
> which still makes me giggle.  And #\ is backed by special code so it's
> faster too.
>
>
> (;@:(<@(<\))~ >:@i.@#) 'abcdefg'
>
> engages the special code for ;@:(<@f)) which avoids boxing overhead and
> speeds up ; .  All the parentheses are necessary for the fast form to be
> recognized.
>
> Henry Rich
>
> On 10/24/2019 10:49 PM, Ric Sherlock wrote:
> > Tacit versions of my original
> >
> >
> > ;@(>:@i.@# <@(<\) ]) 'abcdefg'
> >
> >
> > or if you like hooks:
> >
> > ;@(<@(<\)~ >:@i.@#) 'abcdefg'
> >
> >
> >
> > On Fri, Oct 25, 2019 at 10:16 AM 'robert therriault' via Programming <
> > programming at jsoftware.com> wrote:
> >
> >> Hey Skip,
> >>
> >> My tacit equivalents, although not exactly equivalent since the tacit
> can
> >> be extended to longer strings.
> >>
> >>     a#~-.(<'')=a=.,(>:i.5)<\'abcde'  NB. Skip's version
> >> ┌─┬─┬─┬─┬─┬──┬──┬──┬──┬───┬───┬───┬────┬────┬─────┐
> >> │a│b│c│d│e│ab│bc│cd│de│abc│bcd│cde│abcd│bcde│abcde│
> >> └─┴─┴─┴─┴─┴──┴──┴──┴──┴───┴───┴───┴────┴────┴─────┘
> >>     ((<'') -.~ ])@:(,@:((1+i.@:#)<\ ]))'abcde'  NB. tacit version
> >> ┌─┬─┬─┬─┬─┬──┬──┬──┬──┬───┬───┬───┬────┬────┬─────┐
> >> │a│b│c│d│e│ab│bc│cd│de│abc│bcd│cde│abcd│bcde│abcde│
> >> └─┴─┴─┴─┴─┴──┴──┴──┴──┴───┴───┴───┴────┴────┴─────┘
> >>     ((<'') -.~ ])@:(,@:((1+i.@:#)<\ ]))'abcdef' NB. six character
> string
> >> example
> >>
> >>
> ┌─┬─┬─┬─┬─┬─┬──┬──┬──┬──┬──┬───┬───┬───┬───┬────┬────┬────┬─────┬─────┬──────┐
> >>
> >>
> │a│b│c│d│e│f│ab│bc│cd│de│ef│abc│bcd│cde│def│abcd│bcde│cdef│abcde│bcdef│abcdef│
> >>
> >>
> └─┴─┴─┴─┴─┴─┴──┴──┴──┴──┴──┴───┴───┴───┴───┴────┴────┴────┴─────┴─────┴──────┘
> >>     a: -.~ ,(>:i.5)<\'abcde'   NB. Ric's version
> >> ┌─┬─┬─┬─┬─┬──┬──┬──┬──┬───┬───┬───┬────┬────┬─────┐
> >> │a│b│c│d│e│ab│bc│cd│de│abc│bcd│cde│abcd│bcde│abcde│
> >> └─┴─┴─┴─┴─┴──┴──┴──┴──┴───┴───┴───┴────┴────┴─────┘
> >>     (a: -.~ ,@:((>:@:i.@:#) <\ ]))'abcde'  NB. tacit version
> >> ┌─┬─┬─┬─┬─┬──┬──┬──┬──┬───┬───┬───┬────┬────┬─────┐
> >> │a│b│c│d│e│ab│bc│cd│de│abc│bcd│cde│abcd│bcde│abcde│
> >> └─┴─┴─┴─┴─┴──┴──┴──┴──┴───┴───┴───┴────┴────┴─────┘
> >>     (a: -.~ ,@:((>:@:i.@:#) <\ ]))'abcdef' NB. six character string
> example
> >>
> >>
> ┌─┬─┬─┬─┬─┬─┬──┬──┬──┬──┬──┬───┬───┬───┬───┬────┬────┬────┬─────┬─────┬──────┐
> >>
> >>
> │a│b│c│d│e│f│ab│bc│cd│de│ef│abc│bcd│cde│def│abcd│bcde│cdef│abcde│bcdef│abcdef│
> >>
> >>
> └─┴─┴─┴─┴─┴─┴──┴──┴──┴──┴──┴───┴───┴───┴───┴────┴────┴────┴─────┴─────┴──────┘
> >>
> >> Cheers, bob
> >>
> >>
> >>> On Oct 24, 2019, at 12:59 PM, Skip Cave <skip at caveconsulting.com>
> wrote:
> >>>
> >>> I'm sure this can be reduced by J experts in implicit coding.
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