[racket] do loops in racket, also srfi/25 query

Hi Joe,

On Mon, Mar 26, 2012 at 21:22, Joe Gilray <jgilray at gmail.com> wrote:

> Hi Pierpaolo,
>
> Yes, I could read the data into a list and then create an array from it:
>
> (array-ref (apply array (shape 0 3 0 3) '(1 2 3 4 5 6 7 8 9)) 2 2)
> 9
>
> But, I don't seem to be able to do the same from a vector:
>
> (array-ref (apply array (shape 0 3 0 3) #(1 2 3 4 5 6 7 8 9)) 2 1)
> apply: expects type <proper list> as 3rd argument, given: '#(1 2 3 4 5 6
> 7 8 9); other arguments were: #<procedure:array>
> #<array:srfi-9-record-type-descriptor>
>
>
>

It's late night here and I didn't look at the docs, but from the error
message it seems that you cannot pass a vector to the array constructor.
With a vector at hand, we can use vector->list to do the appropriate
conversion:

(array-ref (apply array (shape 0 3 0 3) (vector->list #(1 2 3 4 5 6 7 8
9))) 2 1)


On racket.exe:

Welcome to Racket v5.2.1.
> (require srfi/25)
> (array-ref (apply array (shape 0 3 0 3) (vector->list #(1 2 3 4 5 6 7 8
9))) 2 1)
8



[]'s

Rodolfo
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20120327/b349eaae/attachment.html>