lazy thoughts

[Daniel Keep]

Andrei Alexandrescu wrote:
> [snip]

I like the idea of lazy evaluation; heck, I toyed around with stack 
threads so I could write generators.

> Also, lazy evaluation has the risk of getting confusing as there's a lot 
> of escaping. Consider:
> 
> int[] arr = [ 1, 2, 3, 4 ];
> auto squares = map!("a * a")(arr);
> arr[] = [ 5, 6, 7, 8 ];
> 
> Now iterating squares will see different numbers than the original ones.
> 
> Please let me know what you think!
> 
> Andrei

Maybe map should only take invariant data; that way, it's fairly obvious 
to the user that you need to pass a block of data that isn't going to be 
changed under the map's feet.

   -- Daniel