Implement DebugStruct::non_exhaustive.#66716
Merged
bors merged 2 commits intorust-lang:masterfrom Jan 17, 2020
Merged
Conversation
Contributor
|
r? @kennytm (rust_highfive has picked a reviewer for you, use r? to override) |
rust-highfive
added
the
S-waiting-on-review
Contributor
Author
|
r? @scottmcm since they saw the internals post. |
CAD97
reviewed
Nov 24, 2019
src/libcore/fmt/builders.rs
Outdated
Contributor
There was a problem hiding this comment.
I'd add a field foo to this structure, just for clarity's sake.
Probably Box<dyn (pick your favorite object safe trait that isn't `Debug`)>.
Contributor
|
Would it be simpler to print e.g. smth like pub fn non_exhaustive(&mut self) -> &mut DebugStruct<'a, 'b> {
self.result = self.result.and_then(|_| {
if self.is_pretty() {
if !self.has_fields {
self.fmt.write_str(" {\n")?;
}
let mut slot = None;
let mut state = Default::default();
let mut writer = PadAdapter::wrap(&mut self.fmt, &mut slot, &mut state);
writer.write_str("..\n")
} else {
let prefix = if self.has_fields { ", " } else { " { " };
self.fmt.write_str(prefix)?;
self.fmt.write_str("..")
}
});
self.has_fields = true;
self
}
pub fn finish_non_exhaustive(&mut self) -> fmt::Result {
self.non_exhaustive().finish()
} |
Contributor
Author
That is certainly another possibility, I'd be interested to hear other people's opinions. |
CAD97
reviewed
Nov 24, 2019
src/libcore/fmt/builders.rs
Outdated
Contributor
There was a problem hiding this comment.
🚩🚩🚩🚩🚩🚩
You do not want to use .into_iter().copied() here. This takes an autoref to &[_] and will break when we eventually add impl IntoIterator for [_]. Use .iter() instead.
Member
|
Ping from triage: @scottmcm - all checks pass, can you please review this PR? |
Member
|
Pinging again from triage: |
|
r? @dtolnay |
dtolnay
reviewed
Dec 15, 2019
Member
dtolnay
left a comment
dtolnay
left a comment
There was a problem hiding this comment.
Thanks! I would be on board with supporting .. in DebugStruct.
-
I think opaque_field should be removed from this PR. It is easy enough to get the same behavior with
field("field", &format_args!("_")). But the representationStruct { field: _ }is not one that I find intuitive or would want to encourage. Almost anything would be better, for examplefield("field", &format_args!("<some Iterator>")). I would prefer to leave this up to the caller rather than dictating a default representation for opaque fields. This way the caller can write an impl that is as useful as possible within their constraints. -
The bool argument of non_exhaustive doesn't seem useful. The caller would pretty much always need to pass true which is just noisy. In the rare case that a struct may or may not print as nonexhaustive depending on a runtime decision, the Debug impl can use an
ifaround the non_exhaustive call. -
I would lean toward making this an alternative to
finishto sidestep the ambiguity about what it should do if you print more fields after calling non_exhaustive.f.debug_struct("Struct").field("field", &self.field).finish_non_exhaustive()
Contributor
|
The job Click to expand the log.I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact |
Member
|
Thanks @derekdreery! This looks good to me. Could you please file a tracking issue and put the issue number into the #[unstable(...)] attribute in the PR? After that I'm happy to merge this. |
richard-uk1
changed the title
DebugStruct::non_exhaustive and DebugStruct::opaque_field.DebugStruct::non_exhaustive.
Contributor
Author
|
Tracking issue added :) |
Member
|
Could you also squash the commits down into just one? Thanks! It would also be good to update the PR description to be slightly more commit-y -- e.g., removing open questions, etc. -- since it'll go into the bors merge commit, so is preserved for all history. This is more of a personal pet peeve of mine though :) |
Contributor
Off topic question: bors-ng has a setting where you can ignore any part of the PR description after some special line, which I often set to e.g. Is this something that the rust-lang bors is capable of doing? If not, should we add it? If so, should we enable it and teach people to use it? |
richard-uk1
force-pushed
the
debug_non_exhaustive
branch
from
6303a13 to
985127c
Compare
Contributor
Author
Done and done. |
Member
Collaborator
|
📌 Commit 985127c has been approved by |
Collaborator
|
🌲 The tree is currently closed for pull requests below priority 100, this pull request will be tested once the tree is reopened |
bors
added
S-waiting-on-bors
Mark-Simulacrum
added a commit
to Mark-Simulacrum/rust
that referenced
this pull request
Dec 18, 2019
…=dtolnay
Implement `DebugStruct::non_exhaustive`.
This patch adds a function (finish_non_exhaustive) to add ellipsis before the closing brace when formatting using `DebugStruct`.
## Example
```rust
#![feature(debug_non_exhaustive)]
use std::fmt;
struct Bar {
bar: i32,
hidden: f32,
}
impl fmt::Debug for Bar {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("Bar")
.field("bar", &self.bar)
.non_exhaustive(true) // Show that some other field(s) exist.
.finish()
}
}
assert_eq!(
format!("{:?}", Bar { bar: 10, hidden: 1.0 }),
"Bar { bar: 10, .. }",
);
```
Contributor
|
The job Click to expand the log.I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact |
Collaborator
|
💔 Test failed - checks-azure |
bors
added
S-waiting-on-review
Collaborator
|
☔ The latest upstream changes (presumably #67540) made this pull request unmergeable. Please resolve the merge conflicts. |
dtolnay
added
S-waiting-on-author
Member
|
This needs a rebase but is otherwise ready to land. |
Contributor
|
The job Click to expand the log.I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact |
richard-uk1
force-pushed
the
debug_non_exhaustive
branch
from
dd04a56 to
9864ec4
Compare
Contributor
Author
|
Should be up-to-date now. |
Contributor
|
The job Click to expand the log.I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact |
Member
|
https://dev.azure.com/rust-lang/e71b0ddf-dd27-435a-873c-e30f86eea377/_apis/build/builds/18417/logs/66 looks like it wants a rustfmt of these files. |
kennytm
added
S-waiting-on-review
Contributor
Author
|
ready for review |
Member
|
Thanks! @bors r+ |
Collaborator
|
📌 Commit 73124df has been approved by |
bors
added
S-waiting-on-bors
Collaborator
bors
added a commit
that referenced
this pull request
Jan 17, 2020
Implement `DebugStruct::non_exhaustive`.
This patch adds a function (finish_non_exhaustive) to add ellipsis before the closing brace when formatting using `DebugStruct`.
## Example
```rust
#![feature(debug_non_exhaustive)]
use std::fmt;
struct Bar {
bar: i32,
hidden: f32,
}
impl fmt::Debug for Bar {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("Bar")
.field("bar", &self.bar)
.non_exhaustive(true) // Show that some other field(s) exist.
.finish()
}
}
assert_eq!(
format!("{:?}", Bar { bar: 10, hidden: 1.0 }),
"Bar { bar: 10, .. }",
);
```
Collaborator
|
☀️ Test successful - checks-azure |
5 tasks
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
11 participants
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.
This patch adds a function (finish_non_exhaustive) to add ellipsis before the closing brace when formatting using
DebugStruct.Example