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
If we find a blanket impl for `Trait` but we're matching on an object `Trait`, prefer the object (I think we could perhaps go either way, but this seems safer). Also give a nice error for attempts to manually `impl Trait for Trait`, since they will be ineffectual.
This fixes the problems around ambiguity ICEs relating to `Any` and `MarkerTrait` that were cropping up all over the place. There may still be similar ICEs reported in #21756 that this PR does not address.
Fixes#24015.
Fixes#24051.
Fixes#24037.
Fixes#23853.
Fixes#21942.
cc #21756.
cc @alexcrichton (this fixes crates.io)
r? @aturon
`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
I ran across a comma splice.
I didn't set the "note:" off inside parenthesis. I looked around in other places and saw it both ways, but without surrounding parenthesis seemed to be the more common convention followed elsewhere in the docs. Let me know if you have an overriding preference about that and I'll change it.
r? @steveklabnik
This syncs the _Crates and Modules_ chapter of the book with current output:
* the runs are supposed to be in the project’s directory,
* `rustc` has slightly different error messages (and things like macro line:col numbers),
* Cargo now compiles things into `target/debug`.
Until I can figure out the correct way to configure jemalloc for Bitrig, this patch will correctly disable it. All other build targets remain unchanged.
MacOS X does not ship with Java installed by default. Instead it
includes binary stubs that upon execution pop up a message suggesting
the installation of the JDK.
Since `javac` is only used when `antlr4` is available, it is possible
to work around the popup by only probing for `javac` if `antlr4` has
been successfully detected (in which case the JDK is probably already
installed on the system).
Fixes#23138.
bors