r? @pcwalton
Sorry this is so big, and sorry the first commit is just titled 'wip'.
Some interesting bits
* [LocalServices](f9069baa70) - This is the set of runtime capabilities that *all* Rust code should expect access to, including the local heap, GC, logging, unwinding.
* [impl Reader, etc. for Option](5fbb0949a5) - Constructors like `File::open` return Option<FileStream>. This lets you write I/O code without ever unwrapping an option.
This series adds a lot of [documentation](https://github.com/brson/rust/blob/io/src/libcore/rt/io/mod.rs#L11) to `core::rt::io`.
The drop block has been deprecated for quite some time. This patch series removes support for parsing it and all the related machinery that made drop work.
As a side feature of all this, I also added the ability to annote fields in structs. This allows comments to be properly associated with an individual field. However, I didn't update `rustdoc` to integrate these comment blocks into the documentation it generates.
r? @pcwalton
A month's worth of parser cleanup here. Much of this is new comments and renaming. A number of these commits also remove unneeded code. Probably the biggest refactor here is splitting "parse_item_or_view_item" into two functions; it turns out that the only overlap between items in foreign modules and items in regular modules was macros, so this refactor should make things substantially easier for future maintenance.
before this change, the parser would parse 14.a() as a method call, but
would parse 14.ø() as the floating-point number 14. followed by a function
call. This is because it was checking is_alpha, rather than ident_start,
and was therefore wrong with respect to unicode.
In principle, it seems like a nice idea to abstract over the two
functions that parse blocks (one with inner attrs allowed, one not).
However, the existing one wound up making things more complex than
just having two separate functions, especially after the obsolete
syntax is (will be) removed.
prec.rs no longer had much to do with precedence; the token->binop
function fits better in token.rs, and the one-liner defining the
precedence of 'as' can go next to the other precedence stuff in
ast_util.rs
