[Submission] D Slices

[David Nadlinger]

Doesn't foreach (i, item; ["a", "b", "c"]) {} do it for you?

David


On 6/11/11 6:16 PM, eles wrote:
>>>> Basically, using subtraction in loop conditions is a big no-no.
>
> then... why the compiler allows it? design should eliminate those
> "big no-no"s. else, we tend again to "educate users", see the case
> for not allowing writing:
>
> while(condition);
>
> and requiring instead
>
> while(condition){}
>
> just because the first was... well, a big no-no (at least from the
> maintenance point of view).
>
> next on the list, why not give access to the current index in
> "foreach" instruction? while I find nice to write "foreach" as a
> simpler way to loop through a collection, sometimes you need to do
> some processing function of element's index. yes, there are some
> issues for unordered collections (if any) and this could also prevent
> some compiler optimizations, maybe.
>
> D:
>
> foreach(item; set) {
>    // do something to item
> }
>
> Go:
>
> for index, value := range someCollection {
>    // do something to index and value
> }
>
> ==or==
>
> for index := range someCollection {
>    // do something to index
> }
>
> Go seems to consider index information to be priority over the value
> of the item. While this is debatable, I think it should be well to
> provide the index information too in foreach loops. Maybe with a
> slightly different syntax, such as:
>
> foreach(index; item; set) {
>    // do something to item
> }
>
> what do you think?