Fix representation when printing abstract consts

[w-utter]

Previously, when printing a const generic expr, it would only display it as {{const expr}}. This allows for a more legible representation when printing these out.

I also zipped the types with their constants for abstract consts that contain function calls when using type annotations, eg: foo(S: usize, true: bool) -> usize insteaad of foo(S, true): fn(usize, bool) -> usize for conciseness.

[rustbot]

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[compiler-errors]

I like this a lot

[compiler-errors]

Please squash this into one commit, then I can approve it.

@rustbot author

[w-utter]

Thanks! Just squashed them into one commit.

I also want to look into formatting the statements with parentheses based on the expr tree when I get the chance, as something like -(N + 1) * 2 prints as -N + 1 * 2, but couldn't seem to find a quick solution without wrapping every statement in parenthesis which I don't think looks nice

[compiler-errors]

Ah, I had totally overlooked that. Thanks for pointing it out. I... actually don't think we should be printing out wrong expressions, and we should fix this in this PR.

You should be able to get a precedence from a hir::BinOp (which is a ast::BinOp) by turning it first into an AssocOp via (https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/util/parser/enum.AssocOp.html#method.from_ast_binop) then calling precedence/fixity. You can then compare the precedence and fixity of the LHS and RHS to know when to insert parentheses.

@rustbot author

[compiler-errors]

If you don't want to do this, let's just always parenthesize inner expressions, and I can implement a better heuristic for this.

[w-utter]

No worries, this new commit should take precedence into account when adding parenthesis.

I didn't bother with fixity as the unop kind does not have an equivalent to_hir_binop() and all fixities are already seperated by its respective expr kind so I just had a different implementation for each.

Having a fn for precedence in rustc_middle::ty::consts::kind::Expr would be nice to have and would clean up some of the stuff I wrote, but it seemed out of scope for this pr

[jackh726]

r? compiler-errors

[Dylan-DPC]

@w-utter any updates on this? thanks

[bors]

☔ The latest upstream changes (presumably #122150) made this pull request unmergeable. Please resolve the merge conflicts.

[w-utter]

I completely forgot about this after holiday break 😅 It's finished as far as I remember, I was just waiting on approval

Hopefully I can guess what the unconstrained generic const is first try and it can get merged as I don't have the environment to test it set up anymore

[rustbot]

There are merge commits (commits with multiple parents) in your changes. We have a no merge policy so these commits will need to be removed for this pull request to be merged.

You can start a rebase with the following commands:

$ # rebase
$ git rebase -i master
$ # delete any merge commits in the editor that appears
$ git push --force-with-lease

The following commits are merge commits:

• 70c1ced

[Dylan-DPC]

@w-utter this still has a merge commit in the list of commits. You have to unmerge it or reset that commit using an interactive rebase.

[w-utter]

That took a lot longer than I'd like to admit but we should be all good to go now 😁

[compiler-errors]

@bors r+

[bors]

📌 Commit 7c4b07d has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit 7c4b07d with merge 8579a18...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing 8579a18 to master...

[rust-timer]

Finished benchmarking commit (8579a18): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

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Bootstrap: 669.426s -> 669.396s (-0.00%)
Artifact size: 312.79 MiB -> 312.81 MiB (0.01%)