I prefer an error message. It usually means I messed up (again). If I want
it to wrap as you suggest it is easy to do.
(5|i.7){i.5
0 1 2 3 4 0 1
7$i.5
0 1 2 3 4 0 1
An example as to where I would want an error. I would not want it to select
'a'. I want an error.
'c'(]{~i.~)'abcde'
c
'f'(]{~i.~)'abcde'
|index error
| 'f' (]{~i.~)'abcde'
On Sat, Mar 7, 2009 at 11:06 AM, Bo Jacoby <[email protected]> wrote:
>
> To the very honored designers of J.
>
> The vocabulary states that: "If x is an integer in the range from -n=: #y
> to n-1 , then x{y selects item n|x from y ."
>
> Now my question is the following: What is the purpose of the restriction
> "in the range from -n=: #y to n-1"? Why not simply define: "If x is an
> integer, then x{y selects item (#y)|x from y ." ?
>
> This suggests a generalization of the present definition. Arrays are then
> addressed cyclically, and the distinction between zero-origin indexing and
> one-origin indexing disappears.
>
> For example:
>
> (i. 7) { i. 5 NB. Nobody prefers an error message to a result.
> |index error
> | (i.7) {i.5
>
> (i. 7) { i. 5 NB. My suggestion is the result (here faked).
> 0 1 2 3 4 0 1
>
> (_5+i. 7) { i. 5 NB. it works in an arbitrarily restricted interval
> 0 1 2 3 4 0 1
>
>
>
> Thank you.
>
> Bo Jacoby
>
>
>
>
> Trænger du til at se det store billede? Kelkoo giver dig gode tilbud
> på LCD TV! Se her http://dk.yahoo.com/r/pat/lcd
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>
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