Re: [Bug-apl] quote-quote should display a blank line

[Blake McBride]

Dear David,

First, I assure you, this is how it works.

I do know of a 0⍴<value> idiom for branching and for nullifying a prior value in a subsequent assignment.  I am unaware of any need for that idiom to prevent printing.  Can you give me one example in a function?

Thanks.

Blake

On Tue, May 27, 2014 at 2:32 PM, David B. Lamkins <address@hidden> wrote:

I find this confusing and counterintuitive.

If displaying an empty vector causes the interpreter to emit a CR, what
then becomes of the 0⍴<value> idiom commonly used to suppress display of
<value>? Wouldn't your output be littered with spurious CRs every time
your program executed such a line?

I spent a half-hour digging through the IBM and ISO references, finding
nothing on the subject of display of empty vectors.

On Tue, 2014-05-27 at 13:04 -0500, Blake McBride wrote:
> a.  Neither an empty vector nor a vector of multiple elements has a CR
> in it.  The system prints the vector, and then prints a CR.  CR gets
> printed either way.
>
>
> b.  I found all these errors while porting my production code which
> ran consistently over IBM APL and several other APL's.  They all print
> a blank line.
>
>
> On Tue, May 27, 2014 at 12:57 PM, David B. Lamkins <address@hidden>
> wrote:
>         How is that so? '' is an empty vector.
>
>         On Mon, 2014-05-26 at 20:30 -0500, Blake McBride wrote:
>         >       ∇test
>         > [1] '1'
>         > [2] ' '
>         > [3] '2'
>         > [4] ''
>         > [5] '3'
>         > [6] ∇
>         >       test
>         > 1
>         >
>         > 2
>         > 3
>         >
>         >
>         >
>         >
>         > There should be a blank line between 2 and 3.
>         >
>         >
>         > Thanks.
>         >
>         >
>         > Blake
>         >
>         >
>
>
>
>