To further illustrate Raul's post using Shape ($)
my_empty =: }. 1
my_empty NB. Empty list
$ my_empty NB. Shape of empty list
0
f my_empty NB. 1 prepended to empty list
1
$ f my_empty NB. Shape is now 1 -- $ 1,my_empty
1
< my_empty NB. my_empty is boxed
┌┐
││
└┘
$ < my_empty NB. Box is an atom -- shape is empty
$ each < my_empty NB. Inside box is shape 0 -- each=:&.> is an adverb that
opens the box, then performs the action on contents, and closes the box
┌─┐
│0│
└─┘
I would add to Raul's observation about which problems 'fit' J; it is usually
my 'way of thinking' about the problem that does not 'fit' J. If you state the
problem then you may find that the solution is found by changing the structure
of the data or some other paradigm shift. I am always amazed at the creativity
of the people on this list when it comes to problem solving.
Cheers, bob
> On Jun 7, 2017, at 10:11 AM, Raul Miller <[email protected]> wrote:
>
> What you are seeing here is not an empty list of boxes but a box
> containing an empty. Or, ok, yes: "an empty box".
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