Plans for creating a Range class/extension type comparable to Rust's Range structs?

[cds-reis]

With the new addition to the range(int start, int end) function, I was wandering if there are any plans to replicate Rust's Range structs (https://doc.rust-lang.org/std/ops/index.html#structs) to the project, with the options to create different types of Ranges (differentiating between inclusive or exclusive, and bounded or unbounded), and using it on Iterables to create Slices (I know Slice already has a way to do it, but AFAIK only with indexes).

If there isn't any plan, I wouldn't mind doing it myself btw.

[mcmah309]

I considered it, but I couldn't define an api that I considered idiomatic for Dart.
Something like

for(final x in RangeInclusive(0,10)) {

}
for(final x in arr(RangeInclusive(0,10))) {

}

Didn't sit right with me. While

for x in 0..=10 {

}
for x in &arr[0..=10] {

}

Is more natural for Rust.
This felt more natural for Dart

for(final x in range(0, 10 + 1)) { // just an example, 11 is obviously preferred

}
for(final x in arr.slice(0, 10 + 1)) {

}

I also explored adding inclusive and exclusive to range e.g.

Iterable<int> range(int start, int end, {bool sInc = true, bool eInc = false}) {
  if (!sInc) start += 1;
  if (eInc) end += 1;
...
}

But this doesn't really add anything IMO because setting eInc = true is the same adding 1 to end as previously shown.

Open to differing opinions though, and If you have an idea for an api and it flows well with the language, definitely interested in hearing as well!

[mcmah309]

After sitting on it for a bit longer, I don't see a reason not to add it. User choice. If you want to work on something I'm for it!

[mcmah309]

I had some time today so I ended up implementing it! https://mcmah309.github.io/rust_core/libs/ops/ops.html#rangebounds

[cds-reis]

Yeah I like this implementation. I also wish there was some extensions on int to make creating ranges easier, like:

import 'range.dart' as r;

extension RangeExtensions on int {
    Iterable<int> range(int end) => r.range(this, end);
}

void main() {
    for (int index in 0.range(10) {
        // ...
    }
}

I would also be weary of the current implementation of the range function, since it gives a bounded range, even if sometimes you would like for it to be unbounded. I would advise to let the default range be a strict range(int start, int end), and then create variations from it, to avoid creating some confusion.

[mcmah309]

As a matter of opinion, since 0.range(10) has the exact same number of characters of range(0,10) (could also be range(10)), I don't find adding another variation compelling. But certainly if you like it, go for it!

More often than not, we reach for bounded ranges than unbounded ones, thus that became the default. Which is the same behavior in python. If an unbounded range is desired, one could

for(int x in RangeFrom(0)){} // 0, 1, 2, ...
for(int x in RangeFrom(0).iter().stepBy(10).map((e) => -1 * e)){} // 0, -10, -20, ...

Maybe something can simplify the second case though, but all the RangeBounds classes have the same behavior as the Rust ones. The Range class fulfills range(int start, int end).