Re: APL2 Compatibility

[Hans-Peter Sorge]

Hi,

In my mind I mostly think in "elements" - not rank or shape.

That is  "L-element OP R-element" . Where elements have an empty rank 
(scalar, ⊂..). And APL takes care of ranks, shapes and depth.

⍝ as you mentioned (and I had to remember):  'a' 'b' ≡ 'ab'
⍝ that is a vector of single chars is a char vector.

       (⊂ 1 2) /¨'a' 'b'  ⍝  (1 2/'a') (1 2/'b')
 aaa bbb

what I want:
        (1 2/¨'a') (1 2/¨'b')
  a aa    b bb

My initial puzle was ( and as you pointed out) a scalar and a one 
element vector are being treated equally.

in my expression
         (⊂1 2) (/¨) (,¨) 'ab'
I ignored that  (,¨) operates on 'ab' and that it does not return 'ab' 
element-wise


so this does the job:
      (⊂ 1 2) (/¨)¨(,¨)'ab'
  a aa    b bb

Thank you for your patience

Best regards
Hans-Peter


Am 27.11.20 um 10:26 schrieb Jay Foad:
> I'm not sure what you're saying. Replicate does tolerate a scalar on
> the right and treat it like a 1-element vector:
>
>        (,6)/'a'
> aaaaaa
>        (,6)/,'a'
> aaaaaa
>
> Your examples are showing something different, where you're
> introducing an extra level of nesting to the right argument but
> without changing its rank or shape.
>
> Jay.
>
> On Thu, 26 Nov 2020 at 23:56, Hans-Peter Sorge
> <hanspetersorge@netscape.net> wrote:
> > Hi Jay,
> >
> > .. not quite:
> >
> >         (,6)/'a'
> > aaaaaa
> >
> >         (,6)/,¨'a'
> >    a a a a a a
> >
> >         (,6)/'abc'
> > aaaaaabbbbbbcccccc
> >
> >        (,6)/,¨'abc'
> >    a a a a a a b b b b b b c c c c c c
> >
> >         (,6)/¨,¨'abc'
> >    aaaaaa bbbbbb cccccc
> >
> > Hans-Peter
> >
> > Am 26.11.20 um 16:24 schrieb Jay Foad:
> > > Hi,
> > >
> > > > Here comes my irritation. Or some missing knowledge ....
> > > > ⍝ 11 - if this is true ( from ⍝3 )
> > > >        (⊂1 2 3)/¨'ABC'
> > > >    AAAAAA BBBBBB CCCCCC
> > > >
> > > > ⍝ 12 - then this schould be different
> > > >         (⊂1 2 3)/¨,¨'ABC'
> > > >    AAAAAA BBBBBB CCCCCC
> > > > ⍝ expected
> > > >     A AA AAA  B BB BBB  C CC CCC
> > > I think they are the same because:
> > > 6/¨'abc'
> > > 6/¨,¨'abc'
> > > are the same, because:
> > > 6/'a'
> > > 6/,'a'
> > > are the same, because Replicate tolerates a scalar on the right and
> > > treats it like a 1-element vector.
> > >
> > > Jay.