[Swift-user] Questions on use of iterate statement

[Michael Wilde]

OK. I was cinsidering that, but I'll need to use a 2-d array as the 
simulation itself generates a vector of results.

I'll try this.

Thanks,

Mike

On 2/20/09 7:45 AM, Ben Clifford wrote:
> In many (all?) cases you should be able to declare an array outside of the 
> iteration, with each element of the array holding the result of each step, 
> like this:
> 
> int j[];
> iterate i {
>   j[i] = i * i;
>   trace(j[i]);
> } until (j[i]>15);
> 
> That was the main way in which I invisioned iterate being used when I 
> implemented it, i think, so that you would map steps of your iteration 
> using a single mapper declaration on j[] rather than inside the iteration 
> body. That comes from imagining it as something like a functional 'unfold' 
> expression (eg 
> http://www.haskell.org/ghc/docs/latest/html/libraries/base/Data-List.html#9) 
> where entire structures such as lists are constructed as a single 
> expression.
> 
> It seems reasonable that body variables be made available to the 
> termination expression, though, to support the style that you attempted, 
> so I'll put that in the bugzilla as a language feature request.
>