Hello Blake,
Please present at least one use case where box/unbox behavior differs
from ⊂/⊃ behavior. For all the use cases you present in your email, I
do not believe there is a difference.
Regards,
Fred Pitts
Retired Chemical Engineer
On Tue, 2014-05-13 at 09:00 -0500, Blake McBride wrote:
> I wrote two APL functions that operate like ⊃ and ⊂ packing an APL1
> array into a scalar and unpacking it back into its APL1 array. It
> works as Iverson preferred, and is simple to understand and use.
> There are no exceptions to what can be nested (i.e. scalars can be
> recursively nested). And there are no data transformations, i.e.
> unboxing always gives you back what you boxed.
>
>
> These functions return an APL2 nested scalar that can be concatenated
> and used like other APL2 nested arrays - you just need to use
> box/unbox rather than ⊂ and ⊃ to box / unbox them.
>
>
> Here are the functions, examples to follow:
>
>
> ∇box[⎕]∇
> [0] z←box x
> [1] z←⊂(⊂⍴x),⊂,x
>
> ∇unbox[⎕]∇
> [0] z←unbox x
> [1] z←(⊃x[⎕IO])⍴⊃(x←⊃x)[⎕IO+1]
>
>
>
> ]boxing 8
> unbox box ,6
> ┌→┐
> │6│
> └─┘
> unbox box 6
> ┌─┐
> │6│
> └─┘
> unbox box ''
> ┌⊖┐
> │ │
> └─┘
> unbox box ⍳3
> ┌→────┐
> │1 2 3│
> └─────┘
> unbox box 0⍴0
> ┌⊖┐
> │0│
> └─┘
> unbox box 'f'
> ┌─┐
> │f│
> └─┘
> ⍴box ⍳3
> ┌⊖┐
> │0│
> └─┘
> unbox unbox unbox box box box 6
> ┌─┐
> │6│
> └─┘
> x←(box ''),(box 6), box ⍳3
> ⍴x
> ┌→┐
> │3│
> └─┘
> unbox x[1]
> ┌⊖┐
> │ │
> └─┘
> unbox x[2]
> ┌─┐
> │6│
> └─┘
> unbox x[3]
> ┌→────┐
> │1 2 3│
> └─────┘
>
> These functions, while not a replacement for ⊂ and ⊃, they do provide
> functionality that is sometimes preferred.
>
>
> Thanks.
>
>
> Blake
>
>
