There was a debate in I.P. Sharp Associates
on the left rank of { , in 1987, prior to the
existence of J. The outcome hinged on the fact
(expressed by Ken Iverson) that left rank 0
permits more sensible index arrays (arrays of
indices). With left rank 1 an index array would
have an extra axis getting in the way of its
manipulation.
----- Original Message -----
From: Raul Miller <[EMAIL PROTECTED]>
Date: Monday, April 23, 2007 9:31 am
Subject: Re: [Jgeneral] a brief insight - why the verb '{' has zero left rank
and infinite right rank
> On 4/22/07, Henry Rich <[EMAIL PROTECTED]> wrote:
> > When x in x { y is boxed, it allows much more complex
> > processing (you'll get to that later). Since boxes are
> > atoms, { applies each box of x individually, hence is
> > left rank 0.
> >
> > The case when x is not boxed is a special case, but the
> > verb still has the left rank 0.
>
> Given the way { is implemented, I think it would make
> more sense if { had a left rank of 1, and a definition like
> <"[EMAIL PROTECTED] from ]
> where from is the current implementation of the { dyad.
>
> (This would imply using {"0 _ to get the current behavior).
>
> That said, the backwards compatability issues are daunting,
> and the payoff for this change seems trivial in comparison.
>
> Besides... indexing items probably is the typical case.
>
> --
> Raul
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