> From: david alis
> b=. +&.>/
> NB. this is equivalent to 1 (+&.>) 2(+&.>) 3 (+&.>) 4
> NB. which is wasteful. The following is better.
> b=. [: < [: +/ >
>
(+&.>//.)/
([: < [: +/ >)/./
I don't think the performance hit is that big for smaller arguments, but if I
was interested in better performance I'd use something more like this to take
advantage of special code for +//.
([: <"0 {. +//. >@{:)
Or I'd use an inverted table as suggested by Bill Lam.
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