In addition to being nicer, this also allows you to use `sum` and `product` for
iterators yielding custom types aside from the standard integers.
Due to removing the `AdditiveIterator` and `MultiplicativeIterator` trait, this
is a breaking change.
[breaking-change]
Hello!
I've been working towards a libsyntax without panics. See:
http://internals.rust-lang.org/t/changing-libsyntax-to-use-result-instead-of-panic/1670
This patch changes the internals of parser.rs to use Result<> rather than panicing. It keeps the following old-style panicing functions as a facade:
parse_expr, parse_item, parse_pat, parse_arm, parse_ty, parse_stmt
I left these functions because I wasn't sure what to do about the quote_* macros or how many syntax-extensions would break if these and quoting macros returned Result.
The gyst of the rest of the patch is:
- Functions in parse/parser.rs return PResult<> rather than panicing
- Other functions in libsyntax call panic! explicitly if they rely on panicing behaviour.
- I added a macro 'panictry!()' to act as scaffolding for callers while converting panicing functions. (This does the same as 'unwrap()' but is easier to grep for and turn into try!()).
Am I on the right track? I'd quite like to get something merged soon as keeping this rebased in the face of libsyntax changes is a lot of work. Please let me know what changes you'd like to see to make this happen.
Thanks!, Phil
`Trait`, prefer the object. Also give a nice error for attempts to
manually `impl Trait for Trait`, since they will be ineffectual.
Fixes#24015.
Fixes#24051.
Fixes#24037.
Fixes#23853.
Fixes#21942.
cc #21756.
- Functions in parser.rs return PResult<> rather than panicing
- Other functions in libsyntax call panic! explicitly for now if they rely on panicing behaviour.
- 'panictry!' macro added as scaffolding while converting panicing functions.
(This does the same as 'unwrap()' but is easier to grep for and turn into try!())
- Leaves panicing wrappers for the following functions so that the
quote_* macros behave the same:
- parse_expr, parse_item, parse_pat, parse_arm, parse_ty, parse_stmt
There are still some remnants we could remove from the compiler (e.g. references to "subtraitrefs"; traits still have variance entries in the variance table), but this removes all user-visible bits I believe.
r? @pnkfelix
Fixes#22806 (since such traits would no longer exist)
These constants are small and can fit even in `u8`, but semantically they have type `usize` because they denote sizes and are almost always used in `usize` context. The change of their type to `u32` during the integer audit led only to the large amount of `as usize` noise (see the second commit, which removes this noise).
This is a minor [breaking-change] to an unstable interface.
r? @aturon
This commit is an implementation of [RFC 979][rfc] which changes the meaning of
the count parameter to the `splitn` function on strings and slices. The
parameter now means the number of items that are returned from the iterator, not
the number of splits that are made.
[rfc]: https://github.com/rust-lang/rfcs/pull/979Closes#23911
[breaking-change]
This commit is an implementation of [RFC 979][rfc] which changes the meaning of
the count parameter to the `splitn` function on strings and slices. The
parameter now means the number of items that are returned from the iterator, not
the number of splits that are made.
[rfc]: https://github.com/rust-lang/rfcs/pull/979Closes#23911
[breaking-change]
The primary purpose of this PR is to add blanket impls for the `Fn` traits of the following (simplified) form:
impl<F:Fn> Fn for &F
impl<F:FnMut> FnMut for &mut F
However, this wound up requiring two changes:
1. A slight hack so that `x()` where `x: &mut F` is translated to `FnMut::call_mut(&mut *x, ())` vs `FnMut::call_mut(&mut x, ())`. This is achieved by just autoderef'ing one time when calling something whose type is `&F` or `&mut F`.
2. Making the infinite recursion test in trait matching a bit more tailored. This involves adding a notion of "matching" types that looks to see if types are potentially unifiable (it's an approximation).
The PR also includes various small refactorings to the inference code that are aimed at moving the unification and other code into a library (I've got that particular change in a branch, these changes just lead the way there by removing unnecessary dependencies between the compiler and the more general unification code).
Note that per rust-lang/rfcs#1023, adding impls like these would be a breaking change in the future.
cc @japaric
cc @alexcrichton
cc @aturon
Fixes#23015.
This PR implements rust-lang/rfcs#1023. In the process it fixes#23086 and #23516. A few impls in libcore had to be updated, but the impact is generally pretty minimal. Most of the fallout is in the tests that probed the limits of today's coherence.
I tested and we were able to build the most popular crates along with iron (modulo errors around errors being sendable).
Fixes#23918.
local only if matches `FUNDAMENTAL(LocalType)`, where `FUNDAMENTAL`
includes `&T` and types marked as fundamental (which includes `Box`).
Also apply these tests to negative reasoning.
case where `None` was returned should never happen in practice; it
amounts to comparing regions from two unrelated hierarchies. (I was also
not able to make it happen.)
const_eval : add overflow-checking for {`+`, `-`, `*`, `/`, `<<`, `>>`}.
One tricky detail here: There is some duplication of labor between `rustc::middle::const_eval` and `rustc_trans::trans::consts`. It might be good to explore ways to try to factor out the common structure to the two passes (by abstracting over the particular value-representation used in the compile-time interpreter).
----
Update: Rebased atop #23841Fix#22531Fix#23030Fix#23221Fix#23235
The overflow-checking attempts to accommodate early evaluation where
we do not have type information yet.
Also, add fixme note about something that has been bothering me.
Moved such overflow checking into one place (in `rustc::middle::ty`,
since it needs to be run on-demand during `const_eval` in some
scenarios), and revised `rustc_typeck` accordingly.
(Note that we only check for overflow if program did not provide a
discriminant value explicitly.)
Fix#23030Fix#23221Fix#23235
* Marks `#[stable]` the contents of the `std::convert` module.
* Added methods `PathBuf::as_path`, `OsString::as_os_str`,
`String::as_str`, `Vec::{as_slice, as_mut_slice}`.
* Deprecates `OsStr::from_str` in favor of a new, stable, and more
general `OsStr::new`.
* Adds unstable methods `OsString::from_bytes` and `OsStr::{to_bytes,
to_cstring}` for ergonomic FFI usage.
[breaking-change]
r? @alexcrichton
This commit cleans out a large amount of deprecated APIs from the standard
library and some of the facade crates as well, updating all users in the
compiler and in tests as it goes along.
