The current indentation level would indicate that Boolean literals are on the same level as Integer and Float literals under Number literals, unindenting moves it to the same scope as Character and string literals, Byte and byte string literals, and Number literals under Literals.
I was reading through the Rust Guide (hopefully looking to learn some Rust), and I figured it would be a good idea to open a pull request with some of the errata I noticed along the way. Most of the changes are pretty mundane, but there are a couple that might raise a bit of discussion.
### Punctuation outside of 'key term' quotes
This is something that was inconsistent in the Guide. While the convention in American English is to place punctuation immediately following a quotation mark *inside* the quotation mark, it seems strange to do this with 'key terms', considering they are not a true quotation.
### Changed comment placement in 17.2 code block
This is what the code block in [17.2 — Ownership, borrowing, and lifetimes](http://doc.rust-lang.org/guide.html#ownership,-borrowing,-and-lifetimes) looks like in fullscreened Safari 8:
Some of the comments extend *just* too far, causing them to bleed into the next line, so I moved a few of them above the relevant lines of code to avoid this.
In the HTML version of the documentation, it isn't rendered so might as well use the unicode representation.
Part of the problem was that putting a math unicode character wasn't
rendering properly in the pdf, so extra steps were needed to define
the unicode charecter ⊥ in reference.tex
closes#15285
- Various grammatical changes
- Place punctuation outside of key term quotes
- Change comment placement in 17.2 code block
- Replace double hyphens with en dashes
This commit is part of a series that introduces a `std::thread` API to
replace `std::task`.
In the new API, `spawn` returns a `JoinGuard`, which by default will
join the spawned thread when dropped. It can also be used to join
explicitly at any time, returning the thread's result. Alternatively,
the spawned thread can be explicitly detached (so no join takes place).
As part of this change, Rust processes now terminate when the main
thread exits, even if other detached threads are still running, moving
Rust closer to standard threading models. This new behavior may break code
that was relying on the previously implicit join-all.
In addition to the above, the new thread API also offers some built-in
support for building blocking abstractions in user space; see the module
doc for details.
Closes#18000
[breaking-change]
The current indentation level would indicate that Boolean literals are on the same level as Integer and Float literals under Number literals, unindenting moves it to the same scope as Character and string literals, Byte and byte string literals, and Number literals under Literals.
followed by a semicolon.
This allows code like `vec![1i, 2, 3].len();` to work.
This breaks code that uses macros as statements without putting
semicolons after them, such as:
fn main() {
...
assert!(a == b)
assert!(c == d)
println(...);
}
It also breaks code that uses macros as items without semicolons:
local_data_key!(foo)
fn main() {
println("hello world")
}
Add semicolons to fix this code. Those two examples can be fixed as
follows:
fn main() {
...
assert!(a == b);
assert!(c == d);
println(...);
}
local_data_key!(foo);
fn main() {
println("hello world")
}
RFC #378.
Closes#18635.
[breaking-change]
In US english, "that" is used in restrictive clauses in place of
"which", and often affects the meaning of sentences.
In UK english and many dialects, no distinction is
made.
While Rust devs want to avoid unproductive pedanticism, it is worth at
least being uniform in documentation such as:
http://doc.rust-lang.org/std/iter/index.html
and also in cases where correct usage of US english clarifies the
sentence.
- Change long inline code to code block
- Replace double-hyphens with en dash
- Miscellaneous rephrasings for clarity
**Edit**: Trivial `commit --amend` to change the commit message slightly.
This is a revival of #19517 (per request of @alexcrichton) now that the new snapshots have landed. We can now remove the last feature gates for if_let, while_let, and tuple_indexing scattered throughout the test sources since these features have been added to Rust.
Closes#19473.
In US english, "that" is used in restrictive clauses in place of
"which", and often affects the meaning of sentences.
In UK english and many dialects, no distinction is
made.
While Rust devs want to avoid unproductive pedanticism, it is worth at
least being uniform in documentation such as:
http://doc.rust-lang.org/std/iter/index.html
and also in cases where correct usage of US english clarifies the
sentence.
This change makes the compiler no longer infer whether types (structures
and enumerations) implement the `Copy` trait (and thus are implicitly
copyable). Rather, you must implement `Copy` yourself via `impl Copy for
MyType {}`.
A new warning has been added, `missing_copy_implementations`, to warn
you if a non-generic public type has been added that could have
implemented `Copy` but didn't.
For convenience, you may *temporarily* opt out of this behavior by using
`#![feature(opt_out_copy)]`. Note though that this feature gate will never be
accepted and will be removed by the time that 1.0 is released, so you should
transition your code away from using it.
This breaks code like:
#[deriving(Show)]
struct Point2D {
x: int,
y: int,
}
fn main() {
let mypoint = Point2D {
x: 1,
y: 1,
};
let otherpoint = mypoint;
println!("{}{}", mypoint, otherpoint);
}
Change this code to:
#[deriving(Show)]
struct Point2D {
x: int,
y: int,
}
impl Copy for Point2D {}
fn main() {
let mypoint = Point2D {
x: 1,
y: 1,
};
let otherpoint = mypoint;
println!("{}{}", mypoint, otherpoint);
}
This is the backwards-incompatible part of #13231.
Part of RFC #3.
[breaking-change]
The test harness will make sure that the panic message contains the
specified string. This is useful to help make `#[should_fail]` tests a
bit less brittle by decreasing the chance that the test isn't
"accidentally" passing due to a panic occurring earlier than expected.
The behavior is in some ways similar to JUnit's `expected` feature:
`@Test(expected=NullPointerException.class)`.
Without the message assertion, this test would pass even though it's not
actually reaching the intended part of the code:
```rust
#[test]
#[should_fail(message = "out of bounds")]
fn test_oob_array_access() {
let idx: uint = from_str("13o").unwrap(); // oops, this will panic
[1i32, 2, 3][idx];
}
```
In regards to:
https://github.com/rust-lang/rust/issues/19253#issuecomment-64836729
This commit:
* Changes the #deriving code so that it generates code that utilizes fewer
reexports (in particur Option::* and Result::*), which is necessary to
remove those reexports in the future
* Changes other areas of the codebase so that fewer reexports are utilized
Using `and` here instead of `but` sounds better to me, as but makes it sound like an item which is still under active development shouldn't normally require more testing, but this one does - or something like that :-)
@steveklabnik?
This is a work in progress, but this should get *extensive* review, so I'm putting it up early and often.
This is the start of a draft of the new 'ownership guide,' which explains ownership, borrowing, etc. I'm feeling better about this framing than last time's, but we'll see.
The "Returning Pointers" section of the pointers guide broke from the convention of putting code between backticks. This PR fixes that. There's also a little trailing whitespace I took care of.
The reason given didn't make any sense when I read it when reading through the docs. I think this is more clear. Please let me know it is also more correct.
This PR completes the removal of the runtime system and green-threaded abstractions as part of implementing [RFC 230](https://github.com/rust-lang/rfcs/pull/230).
Specifically:
* It removes the `Runtime` trait, welding the scheduling infrastructure directly to native threads.
* It removes `libgreen` and `libnative` entirely.
* It rewrites `sync::mutex` as a trivial layer on top of native mutexes. Eventually, the two modules will be merged.
* It hides the vast majority of `std::rt`.
This completes the basic task of removing the runtime system (I/O and scheduling) and components that depend on it.
After this lands, a follow-up PR will pull the `rustrt` crate back into `std`, turn `std::task` into `std::thread` (with API changes to go along with it), and completely cut out the remaining startup/teardown sequence. Other changes, including new [TLS](https://github.com/rust-lang/rfcs/pull/461) and synchronization are in the RFC or pre-RFC phase.
Closes#17325Closes#18687
[breaking-change]
r? @alexcrichton
Futureproof Rust for fancier suffixed literals. The Rust compiler tokenises a literal followed immediately (no whitespace) by an identifier as a single token: (for example) the text sequences `"foo"bar`, `1baz` and `1u1024` are now a single token rather than the pairs `"foo"` `bar`, `1` `baz` and `1u` `1024` respectively.
The compiler rejects all such suffixes in the parser, except for the 12 numeric suffixes we have now.
I'm fairly sure this will affect very few programs, since it's not currently legal to have `<literal><identifier>` in a Rust program, except in a macro invocation. Any macro invocation relying on this behaviour can simply separate the two tokens with whitespace: `foo!("bar"baz)` becomes `foo!("bar" baz)`.
This implements [RFC 463](https://github.com/rust-lang/rfcs/blob/master/text/0463-future-proof-literal-suffixes.md), and so closes https://github.com/rust-lang/rust/issues/19088.
As-is, there's no indication that the code examples pop out into a window that runs on `play.rust-lang.org` until you mouse over them. I managed to get to section 4 of the guide before realizing you could do this since it didn't occur to me to mouse over the example text.
cc @rose since we went through the tutorial together and I think it wasn't obvious to her either.
Now that we've done `fail` -> `panic`, I feel bringing back the error handling guide is a good idea. We had one long ago, but it was removed when conditions were removed.
This doesn't cover the new FromError stuff, but I feel like it's already useful in this state, so I'm sending this PR now.
This breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:
```
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
=>
```
pub use self::Foo::{A, B};
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
or
```
pub enum Foo {
A,
B
}
fn main() {
let a = Foo::A;
}
```
[breaking-change]
As a new user, I spent a while confused when flycheck told me the code sample I'd typed in was invalid. I ended up figuring out some of what comes after the code sample more painfully by myself because there was no indication that it was broken in the text beforehand. This one line change makes it clear that the code following it is an experiment that may not work rather than something to assume just works.
This removes some leftover line-numbering cruft from elided error examples and brings some minor clarifications.
I’m not super happy about the ‘we cannot have two mutable pointers that point to the same memory’ wording (to the best of my understanding we can’t even have one mutable and one immutable), but other attempts to word this were derailing the flow a bit too much.
* Moves multi-collection files into their own directory, and splits them into seperate files
* Changes exports so that each collection has its own module
* Adds underscores to public modules and filenames to match standard naming conventions
(that is, treemap::{TreeMap, TreeSet} => tree_map::TreeMap, tree_set::TreeSet)
* Renames PriorityQueue to BinaryHeap
* Renames SmallIntMap to VecMap
* Miscellanious fallout fixes
[breaking-change]
I think it helps to show that the variables introduced in match blocks are indeed independent from the matched variable `x` (especially when `x` is still reachable inside those blocks and might be useful), so this renames them accordingly. Maybe some linter (or language-level warning?) will eventually warn about shadowing `x` in such cases. ;)
I’m not super happy about the matching-on-range example, as it’s too contrived (`e` and `x` are exactly the same here), but I couldn’t come up with something both simple and non-redundant.
This in-progress PR implements https://github.com/rust-lang/rust/issues/17489.
I made the code changes in this commit, next is to go through alllllllll the documentation and fix various things.
- Rename column headings as appropriate, `# Panics` for panic conditions and `# Errors` for `Result`s.
- clean up usage of words like 'fail' in error messages
Anything else to add to the list, @aturon ? I think I should leave the actual functions with names like `slice_or_fail` alone, since you'll get to those in your conventions work?
I'm submitting just the code bits now so that we can see it separately, and I also don't want to have to keep re-building rust over and over again if I don't have to 😉
Listing all the bits so I can remember as I go:
- [x] compiler-rt
- [x] compiletest
- [x] doc
- [x] driver
- [x] etc
- [x] grammar
- [x] jemalloc
- [x] liballoc
- [x] libarena
- [x] libbacktrace
- [x] libcollections
- [x] libcore
- [x] libcoretest
- [x] libdebug
- [x] libflate
- [x] libfmt_macros
- [x] libfourcc
- [x] libgetopts
- [x] libglob
- [x] libgraphviz
- [x] libgreen
- [x] libhexfloat
- [x] liblibc
- [x] liblog
- [x] libnative
- [x] libnum
- [x] librand
- [x] librbml
- [x] libregex
- [x] libregex_macros
- [x] librlibc
- [x] librustc
- [x] librustc_back
- [x] librustc_llvm
- [x] librustdoc
- [x] librustrt
- [x] libsemver
- [x] libserialize
- [x] libstd
- [x] libsync
- [x] libsyntax
- [x] libterm
- [x] libtest
- [x] libtime
- [x] libunicode
- [x] liburl
- [x] libuuid
- [x] llvm
- [x] rt
- [x] test
This includes updating the language items and marking what needs to
change after a snapshot.
If you do not use the standard library, the language items you need to
implement have changed. For example:
```rust
#[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
```
is now
```rust
#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }
```
Related, lesser-implemented language items `fail` and
`fail_bounds_check` have become `panic` and `panic_bounds_check`, as
well. These are implemented by `libcore`, so it is unlikely (though
possible!) that these two renamings will affect you.
[breaking-change]
Fix test suite
https://github.com/rust-lang/rfcs/pull/221
The current terminology of "task failure" often causes problems when
writing or speaking about code. You often want to talk about the
possibility of an operation that returns a Result "failing", but cannot
because of the ambiguity with task failure. Instead, you have to speak
of "the failing case" or "when the operation does not succeed" or other
circumlocutions.
Likewise, we use a "Failure" header in rustdoc to describe when
operations may fail the task, but it would often be helpful to separate
out a section describing the "Err-producing" case.
We have been steadily moving away from task failure and toward Result as
an error-handling mechanism, so we should optimize our terminology
accordingly: Result-producing functions should be easy to describe.
To update your code, rename any call to `fail!` to `panic!` instead.
Assuming you have not created your own macro named `panic!`, this
will work on UNIX based systems:
grep -lZR 'fail!' . | xargs -0 -l sed -i -e 's/fail!/panic!/g'
You can of course also do this by hand.
[breaking-change]
Some minor wording fixes to the Closures chapter; my brain tripped a few times when reading it, so I tried to come up with something a bit smoother. I’m not a native speaker, so please do review this critically.
Explain that Rust has different pointer types because there is a
tradeoff between flexibility and efficiency. Motivate boxes as
fixed-size containers of variable-sized objects. Clarify that Box and Rc
are pointer types that you deref with * just like references. Stick to
explaining the semantics and avoid implementation details. Scope isn't
the most accurate framework to think about deallocation (since you
return boxes and otherwise move values out of scopes); it's more "when
the value is done being used," i.e., lifetime. Provide a connection
between Rust's pointer types by locating them on a flexibiltiy /
performance scale. Explain the compiler can't statically analyze
lifetimes with multiple owners; hence the need for (runtime) reference
counting.
This should be clearer, and fits in better with the `TTNonterminal` variant.
Renames:
- `TTTok` -> `TTToken`
- `TTDelim` -> `TTDelimited`
- `TTSeq` -> `TTSequence`
Explain the primary disadvantage of garbage collection is runtime
overhead and unpredictable pauses. Elucidate where the name "race
condition" comes from. Emphasize that Rust can guarantee your code is
free of race conditions and other memory errors, with no runtime
overhead.
cc @steveklabnik
This patch contains a fix for:
- single quote around string slice
- string: String is confusing for newbies and it's more readble if the
argument name is different that the argument type name
Explain the primary disadvantage of garbage collection is runtime
overhead and unpredictable pauses. Elucidate where the name "race
condition" comes from. Emphasize that Rust can guarantee your code is
free of race conditions and other memory errors, with no runtime
overhead.
This is an almost-done draft of a guide on crates and modules. This is a hard guide to get right, I had to remove a chunk of the Guide because it was confusing.
I've also pushed up https://github.com/steveklabnik/phrases which has matching code. Whenever we finish this guide, I think it'd be good to have a sample crate like this in the rust-lang org for people to compare against. The hardest part of a guide like this is that it depends on multiple files being correct, and being able to point to a repository would be very helpful.
Things yet to do:
1. external crates via cargo
2. documentation
I'm super open to still revising this if it's still confusing. There's been a lot of Reddit discussion about the module system, and I tried to incorporate those posts and the comments into this.
Use a match expression directly in the println statement, instead of creating a second variable. It seems weird that the current guide.md complains about creating an extra variable, when the same feature could be demonstrated without creating the extra variable.
The array is the fundamental concept; vectors are growable arrays, and
slices are views into either. Show common array ops up front: length
and iteration. Mention arrays are immutable by default. Highlight
definite initialization and bounds-checking as safety features. Show
that you only need a type suffix on one element of initializers.
Explain that vectors are a value-add library type over arrays, not a
fundamental type; show they have the same "interface." Motivate slices
as efficient views into arrays; explain you can slice vectors, Strings,
&str because they're backed by arrays.
All deprecation warnings have been converted to errors. This includes
the warning for multiple cfgs on one item. We'll leave that as an error
for some period of time to ensure that all uses are updated before the
behavior changes from "or" to "and".
All deprecation warnings have been converted to errors. This includes
the warning for multiple cfgs on one item. We'll leave that as an error
for some period of time to ensure that all uses are updated before the
behavior changes from "or" to "and".
The old version switched in between examples from the value `5i` to `"Hello"` and back.
Additionally, the code generated by `rustc print.rs --pretty=expanded` is not as verbose anymore.
Currently, the Guide says tuples "are only equivalent if the arity, types, and values are all identical", before presenting an example that uses `==` to compare two tuples whose arity and contained types match. This is misleading, because it implies that `==` can dynamically check whether two tuples have the same arity and contained types, whereas trying to do this would lead to a compiler error.
I tried to avoid destroying the flow of this section, but I'm not sure if I've been successful.
Because my '30 minute intro' was originally a blog post, the tone was a bit too light. It also was written a long time ago, and deserves a bit of a refresher for modern Rust. now that my work on the Guide is wrapping up, I want to give it a quick re-write as well.
This is not yet done, but I'm submitting it for feedback so far. I'd really like some comments on the ownership part in particular, which gets lower level than before, but is not strictly 100% accurate. Trying to strike a balance.
In general, I'm not sure I go into enough detail for those without systems experience, but am afraid of too much detail for those that do.
Rendered view: https://github.com/steveklabnik/rust/blob/intro_redux/src/doc/intro.md
/cc @wycats @nikomatsakis @brson etc
The old version switched in between examples from the value `5i` to `"Hello"`
and back. Additionally, the code generated by `rustc print.rs
--pretty=expanded` is not as verbose anymore.
Hi,
These are a few small edits to the Guide that I made while reading online. Really well done and approachable.
I have a few questions below, but I don't know if this is the proper place to ask them, so feel free to ignore the below.
1. Trailing commas seem to be a convention in Rust and are used quite a bit throughout the Guide, but are never explicitly mentioned. Maybe adding a short mention about them when they first appear in the Structs section might be helpful to those who are unfamiliar with or don't use them in other languages.
2. In the Iterators section, there is a block of code like this:
```rust
let mut range = range(0i, 10i);
loop {
match range.next() {
Some(x) => {
println!("{}", x);
} // no comma needed?
None => { break }
}
}
```
My inclination would be to put a comma where the comment is to separate the two arms to get this to compile, but it runs fine either way. Is there a convention on commas for scenarios like this where each arm is enclosed in `{}`?
All the best,
O-I
Oddly (to me), this code runs fine without the comma separating the `Some` and `None` arms of the `match` construct. It seems like Rust doesn't require you to separate arms with commas if all the expressions are enclosed in braces.
