Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add a try_collect() helper method to Iterator #94041

Merged
merged 1 commit into from
Feb 18, 2022

Conversation

a-lafrance
Copy link
Contributor

Implement Iterator::try_collect() as a helper around Iterator::collect() as discussed here.

First time contributor so definitely open to any feedback about my implementation! Specifically wondering if I should open a tracking issue for the unstable feature I introduced.

As the main participant in the internals discussion: r? @scottmcm

@rust-highfive
Copy link
Collaborator

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @scottmcm (or someone else) soon.

Please see the contribution instructions for more information.

@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 16, 2022
@scottmcm scottmcm added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 16, 2022
@a-lafrance
Copy link
Contributor Author

Updated the try_collect() implementation to accept Try-not-FromIterator types like ControlFlow. Also modified the docs to get the main points of the method across better.

@rustbot label -S-waiting-on-author +S-waiting-on-review

@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Feb 16, 2022
@rust-log-analyzer

This comment has been minimized.

@scottmcm
Copy link
Member

scottmcm commented Feb 16, 2022

That CI failure makes no sense. I'll try closing and reopening.

@scottmcm scottmcm closed this Feb 16, 2022
@scottmcm scottmcm reopened this Feb 16, 2022
@rust-log-analyzer

This comment has been minimized.

@scottmcm scottmcm added S-blocked Status: Blocked on something else such as an RFC or other implementation work. S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 16, 2022
@a-lafrance
Copy link
Contributor Author

Tracking issue: #94047


let u: Vec<Result<i32, ()>> = vec![Ok(1), Ok(2), Ok(3)];
let v = u.into_iter().try_collect::<Vec<i32>>();
assert_eq!(v, Ok(vec![1, 2, 3]));
Copy link
Member

@bjorn3 bjorn3 Feb 16, 2022

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This one is already possible with .collect(). Thanks to impl<A, E, V> FromIterator<Result<A, E>> for Result<V, E> where V: FromIterator<A>.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Right, but the main benefits of try_collect() are increasing the discoverability of this technique and allowing Try-but-not-FromIterator types (e.g. ControlFlow) to be fallibly collected as well. See my comment on the tracking issue here for a more thorough description of the differences between try_collect() and collect().

Tweaked `try_collect()` to accept more `Try` types

Updated feature attribute for tracking issue
@ehuss
Copy link
Contributor

ehuss commented Feb 16, 2022

The ICE in CI is caused by the use of intra-doc links involving core (the ones that are [`ControlFlow`]: core::ops::ControlFlow` and [`FromIterator`]: core::iter::FromIterator). There is more information in #73445. Obviously it shouldn't ICE and fall apart. I can't explain why that happens.

I'm pretty sure you can just reference them without qualification (like [`FromIterator`], no need for a reference) since they are in scope.

You can test documentation with ./x.py doc --stage 0 library/test. You can add the --open flag to open a web browser to inspect it.

@a-lafrance
Copy link
Contributor Author

Thanks for the info @ehuss! Just pushed a fix for the erring links, so @scottmcm I think it should be ready for a final review.

@rustbot label -S-waiting-on-author +S-waiting-on-review

@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Feb 16, 2022
@a-lafrance
Copy link
Contributor Author

Oh, and @rustbot label -S-blocked

@rustbot rustbot removed the S-blocked Status: Blocked on something else such as an RFC or other implementation work. label Feb 16, 2022
@scottmcm
Copy link
Member

scottmcm commented Feb 17, 2022

Thank you, ehuss! And for the PR + updates, @a-lafrance!

This looks good to go into unstable by me. Lots more discussion to be had on the tracking issue, to be sure.
@bors r+

@bors
Copy link
Contributor

bors commented Feb 17, 2022

📌 Commit 47d5196 has been approved by scottmcm

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 17, 2022
bors added a commit to rust-lang-ci/rust that referenced this pull request Feb 17, 2022
…askrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang#93337 (Update tracking issue numbers for inline assembly sub-features)
 - rust-lang#93758 (Improve comments about type folding/visiting.)
 - rust-lang#93780 (Generate list instead of div items in sidebar)
 - rust-lang#93976 (Add MAIN_SEPARATOR_STR)
 - rust-lang#94011 (Even more let_else adoptions)
 - rust-lang#94041 (Add a `try_collect()` helper method to `Iterator`)
 - rust-lang#94043 (Fix ICE when using Box<T, A> with pointer sized A)
 - rust-lang#94082 (Remove CFG_PLATFORM)
 - rust-lang#94085 (Clippy: Don't lint `needless_borrow` in method receiver positions)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit a4be35e into rust-lang:master Feb 18, 2022
@rustbot rustbot added this to the 1.60.0 milestone Feb 18, 2022
@a-lafrance a-lafrance deleted the try-collect branch February 18, 2022 02:11
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion.
Projects
None yet
Development

Successfully merging this pull request may close these issues.

8 participants