Re: Reassignment of a nested array element

[Dr . Jürgen Sauermann]

    Gentlemen,
      
      thanks for the discussion, fixed in SVN 1655.
      
      Hans-Peter, I am sorry that this change creates an incompatibility
      in your code.
      
      My thinking for the old solution was this:
      
         V←0 0 0  ◊   V←1 ◊ V   ∩ case 1.
      1
      
         V←0 0 0  ◊   V[]←1 ◊ V   ⍝ case 2.
      1 1 1
      
    This applies to GNU APL, APL2, and Dyalog. The question is then if
    (A⊃V) in
    (A⊃B)←X should behave like case 1 or like case 2 above. The case
    (A⊃B)←X
    with nested (A⊃B)is described neither in the "IBM APL2 Language
    Reference"
    nor in the "ISO 13751" standard, leaving some room for
    interpretation.
    
    However, both APL2 and Dyalog agree on case 1 and therefore I
    changed
    GNU APL to behave the same.
    
    Best Regards,
    Jürgen

On 3/4/23 8:25 PM, Hans-Peter Sorge wrote:

> Hi,
>       
>       
>       Works as expected
>       
>       
>       ⊃'Sue' 'Maria' 'Annalisa'
>       
>       is an array 3 by 8.
>       
>       
>       ⊂⊃'Susan' 'Mary' 'Annalisa'
>       
>       is an element (⊂) of a 3 by 8  array (⊃'Susan' 'Mary' 'Annalisa'
>       ).
>       
>       
>       Finally each element in  ⊃'Sue' 'Maria' 'Annalisa' gets assigned
>       an array of  ⊃'Susan' 'Mary' 'Annalisa'
>       
>       
>       Greetings
>       
>       Hans-Peter
>       
>       
>       Am 04.03.23 um 16:53 schrieb Mr. Sunday:
>       
> > Hi,
> >         
> >         
> >         I have an issue with reassigning an element of a nested array. 
> >         Here is an example.
> >         
> >         
> >         14535:15a:~% apl --version
> >         
> >         BUILDTAG:
> >         
> >         ---------
> >         
> >              Project:        GNU APL
> >         
> >              Version / SVN:  1.8 / SVN: 1651M
> >         
> >              Build Date:     2023-03-02 00:25:07 UTC
> >         
> >              Build OS:       Darwin 21.6.0 x86_64
> >         
> >              config.status:  default ./configure options
> >         
> >              Archive SVN:    1621
> >         
> >         
> >         
> >              var←0 0 0 ⋄ (1⊃var)←5 4 ⋄ (2⊃var)←3 4⍴⍳12 ⋄ (3⊃var)←⊃'Sue'
> >         'Maria' 'Annalisa' ⋄ var ⋄ (3⊃var)←⊂⊃'Susan' 'Mary' 'Annalisa' ⋄
> >         var
> >         
> >         ┌→────────────────────────────┐
> >         
> >         │┌→──┐ ┌→─────────┐ ┌→───────┐│
> >         
> >         ││5 4│ ↓1  2  3  4│ ↓Sue     ││
> >         
> >         │└───┘ │5  6  7  8│ │Maria   ││
> >         
> >         │      │9 10 11 12│ │Annalisa││
> >         
> >         │      └──────────┘ └────────┘│
> >         
> >         └ϵ────────────────────────────┘
> >         
> > ┌→───────────────────────────────────────────────────────────────────────────────────────────────────────────┐
> >         
> >         │┌→──┐ ┌→─────────┐
> > ┌→──────────────────────────────────────────────────────────────────────────────────────┐│
> >         ││5 4│ ↓1  2  3  4│ ↓┌→───────┐ ┌→───────┐ ┌→───────┐ ┌→───────┐
> >         ┌→───────┐ ┌→───────┐ ┌→───────┐ ┌→───────┐││
> >         
> >         │└───┘ │5  6  7  8│ │↓Susan   │ ↓Susan   │ ↓Susan   │ ↓Susan   │
> >         ↓Susan   │ ↓Susan   │ ↓Susan   │ ↓Susan   │││
> >         
> >         │      │9 10 11 12│ ││Mary    │ │Mary    │ │Mary    │ │Mary    │
> >         │Mary    │ │Mary    │ │Mary    │ │Mary    │││
> >         
> >         │      └──────────┘ ││Annalisa│ │Annalisa│ │Annalisa│ │Annalisa│
> >         │Annalisa│ │Annalisa│ │Annalisa│ │Annalisa│││
> >         
> >         │                   │└────────┘ └────────┘ └────────┘ └────────┘
> >         └────────┘ └────────┘ └────────┘ └────────┘││
> >         
> >         │                  
> > │                                                                                      
> >         ││
> >         
> >         │                   │┌→───────┐ ┌→───────┐ ┌→───────┐ ┌→───────┐
> >         ┌→───────┐ ┌→───────┐ ┌→───────┐ ┌→───────┐││
> >         
> >         │                   │↓Susan   │ ↓Susan   │ ↓Susan   │ ↓Susan   │
> >         ↓Susan   │ ↓Susan   │ ↓Susan   │ ↓Susan   │││
> >         
> >         │                   ││Mary    │ │Mary    │ │Mary    │ │Mary    │
> >         │Mary    │ │Mary    │ │Mary    │ │Mary    │││
> >         
> >         │                   ││Annalisa│ │Annalisa│ │Annalisa│ │Annalisa│
> >         │Annalisa│ │Annalisa│ │Annalisa│ │Annalisa│││
> >         
> >         │                   │└────────┘ └────────┘ └────────┘ └────────┘
> >         └────────┘ └────────┘ └────────┘ └────────┘││
> >         
> >         │                  
> > │                                                                                      
> >         ││
> >         
> >         │                   │┌→───────┐ ┌→───────┐ ┌→───────┐ ┌→───────┐
> >         ┌→───────┐ ┌→───────┐ ┌→───────┐ ┌→───────┐││
> >         
> >         │                   │↓Susan   │ ↓Susan   │ ↓Susan   │ ↓Susan   │
> >         ↓Susan   │ ↓Susan   │ ↓Susan   │ ↓Susan   │││
> >         
> >         │                   ││Mary    │ │Mary    │ │Mary    │ │Mary    │
> >         │Mary    │ │Mary    │ │Mary    │ │Mary    │││
> >         
> >         │                   ││Annalisa│ │Annalisa│ │Annalisa│ │Annalisa│
> >         │Annalisa│ │Annalisa│ │Annalisa│ │Annalisa│││
> >         
> >         │                   │└────────┘ └────────┘ └────────┘ └────────┘
> >         └────────┘ └────────┘ └────────┘ └────────┘││
> >         
> >         │                  
> > └ϵ──────────────────────────────────────────────────────────────────────────────────────┘│
> > └ϵϵ──────────────────────────────────────────────────────────────────────────────────────────────────────────┘
> >         
> >         
> >         -- Everyday is Sunday.
> >         
> >         
> >       
>       
>