implement DoubleEndedIterator for 1d LanesIter - #1237
Merged
bluss merged 1 commit intoMar 10, 2024
Merged
Conversation
Copy link
Copy Markdown
Contributor
Sorry, something went wrong.
bluss
reviewed
Mar 10, 2024
Comment thread
src/iterators/mod.rs
Outdated
|
|
||
| impl<'a, A, D> DoubleEndedIterator for LanesIter<'a, A, D> | ||
| where | ||
| D: Dimension, |
Copy link
Copy Markdown
Member
There was a problem hiding this comment.
I expected this to be limited to the case where D=Ix1. Just like how .iter()'s Iter works. I think it's better that way, then the Baseiter does not leak out (it's in the where clause, that's a leak of internals into public API.)
Sorry, something went wrong.
Copy link
Copy Markdown
Member
There was a problem hiding this comment.
Fixed that, and also applied the same change to LanesIterMut - it and LanesIter must of course change together.
Sorry, something went wrong.
bluss
force-pushed
the
rev
branch
2 times, most recently
from
5cb455d to
0ec6ede
Compare
March 10, 2024 12:59
bluss
enabled auto-merge
March 10, 2024 13:00
bluss
added this pull request to the merge queue
Mar 10, 2024
github-merge-queue
Bot
removed this pull request from the merge queue due to failed status checks
Mar 10, 2024
This is especially useful when one wants to iterate over rows or columns of a 2d array in reverse. Co-authored-by: Ulrik Sverdrup <bluss@users.noreply.github.com>
bluss
enabled auto-merge
March 10, 2024 13:30
bluss
added this pull request to the merge queue
Mar 10, 2024
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
In a project I wanted to iterate over the rows and columns of a 2d array in reverse but while rows and columns exist, the resulting LanesIter does not implement DoubleEndedIterator as of yet. It is possible to use indexing via row with reversed indices but that is less ergonomic.
This PR fixes this at least for 1d LanesIter and now allows one to do:
let a = ArcArray::from_iter(0..8).reshape((4, 2)); for (row, check) in a.rows().into_iter().rev().zip(&[[6, 7], [4, 5], [2, 3], [0, 1]]) { assert_equal(row, check); }The implementation just delegates to the underlying 1d Baseiter which implements DoubleEndedIterator.
The trait is not implemented for higher dimensions however, which would need some additional work.