Commit Graph

318 Commits

Author SHA1 Message Date
Tom Lee
611c2ae4f1 Try to parse TcpStream::connect 'host' parameter as an IP.
Fall back to get_host_addresses to try a DNS lookup if we can't
parse it as an IP address.
2014-05-12 21:41:48 -07:00
Tom Lee
a57889a580 Easier interface for TCP ::connect and ::bind.
Prior to this commit, TcpStream::connect and TcpListener::bind took a
single SocketAddr argument. This worked well enough, but the API felt a
little too "low level" for most simple use cases.

A great example is connecting to rust-lang.org on port 80. Rust users would
need to:

  1. resolve the IP address of rust-lang.org using
     io::net::addrinfo::get_host_addresses.

  2. check for errors

  3. if all went well, use the returned IP address and the port number
     to construct a SocketAddr

  4. pass this SocketAddr to TcpStream::connect.

I'm modifying the type signature of TcpStream::connect and
TcpListener::bind so that the API is a little easier to use.

TcpStream::connect now accepts two arguments: a string describing the
host/IP of the host we wish to connect to, and a u16 representing the
remote port number.

Similarly, TcpListener::bind has been modified to take two arguments:
a string describing the local interface address (e.g. "0.0.0.0" or
"127.0.0.1") and a u16 port number.

Here's how to port your Rust code to use the new TcpStream::connect API:

  // old ::connect API
  let addr = SocketAddr{ip: Ipv4Addr{127, 0, 0, 1}, port: 8080};
  let stream = TcpStream::connect(addr).unwrap()

  // new ::connect API (minimal change)
  let addr = SocketAddr{ip: Ipv4Addr{127, 0, 0, 1}, port: 8080};
  let stream = TcpStream::connect(addr.ip.to_str(), addr.port()).unwrap()

  // new ::connect API (more compact)
  let stream = TcpStream::connect("127.0.0.1", 8080).unwrap()

  // new ::connect API (hostname)
  let stream = TcpStream::connect("rust-lang.org", 80)

Similarly, for TcpListener::bind:

  // old ::bind API
  let addr = SocketAddr{ip: Ipv4Addr{0, 0, 0, 0}, port: 8080};
  let mut acceptor = TcpListener::bind(addr).listen();

  // new ::bind API (minimal change)
  let addr = SocketAddr{ip: Ipv4Addr{0, 0, 0, 0}, port: 8080};
  let mut acceptor = TcpListener::bind(addr.ip.to_str(), addr.port()).listen()

  // new ::bind API (more compact)
  let mut acceptor = TcpListener::bind("0.0.0.0", 8080).listen()

[breaking-change]
2014-05-12 21:41:48 -07:00
Alex Crichton
f94d671bfa core: Remove the cast module
This commit revisits the `cast` module in libcore and libstd, and scrutinizes
all functions inside of it. The result was to remove the `cast` module entirely,
folding all functionality into the `mem` module. Specifically, this is the fate
of each function in the `cast` module.

* transmute - This function was moved to `mem`, but it is now marked as
              #[unstable]. This is due to planned changes to the `transmute`
              function and how it can be invoked (see the #[unstable] comment).
              For more information, see RFC 5 and #12898

* transmute_copy - This function was moved to `mem`, with clarification that is
                   is not an error to invoke it with T/U that are different
                   sizes, but rather that it is strongly discouraged. This
                   function is now #[stable]

* forget - This function was moved to `mem` and marked #[stable]

* bump_box_refcount - This function was removed due to the deprecation of
                      managed boxes as well as its questionable utility.

* transmute_mut - This function was previously deprecated, and removed as part
                  of this commit.

* transmute_mut_unsafe - This function doesn't serve much of a purpose when it
                         can be achieved with an `as` in safe code, so it was
                         removed.

* transmute_lifetime - This function was removed because it is likely a strong
                       indication that code is incorrect in the first place.

* transmute_mut_lifetime - This function was removed for the same reasons as
                           `transmute_lifetime`

* copy_lifetime - This function was moved to `mem`, but it is marked
                  `#[unstable]` now due to the likelihood of being removed in
                  the future if it is found to not be very useful.

* copy_mut_lifetime - This function was also moved to `mem`, but had the same
                      treatment as `copy_lifetime`.

* copy_lifetime_vec - This function was removed because it is not used today,
                      and its existence is not necessary with DST
                      (copy_lifetime will suffice).

In summary, the cast module was stripped down to these functions, and then the
functions were moved to the `mem` module.

    transmute - #[unstable]
    transmute_copy - #[stable]
    forget - #[stable]
    copy_lifetime - #[unstable]
    copy_mut_lifetime - #[unstable]

[breaking-change]
2014-05-11 01:13:02 -07:00
bors
47ecc2e889 auto merge of #14046 : alexcrichton/rust/ignore-a-test-on-freebsd, r=kballard
This test runs successfully manually, but the bots are having trouble getting
this test to pass. Ignore it on freebsd for now.
2014-05-09 11:01:42 -07:00
bors
52002154c7 auto merge of #14035 : alexcrichton/rust/experimental, r=huonw
This was intended as part of the I/O timeouts commit, but it was mistakenly
forgotten. The type of the timeout argument is not guaranteed to remain constant
into the future.
2014-05-09 02:41:36 -07:00
Kevin Ballard
eab6bb2ece Handle fallout in documentation
Tweak the tutorial's section on vectors and strings, to slightly clarify
the difference between fixed-size vectors, vectors, and slices.
2014-05-08 12:06:22 -07:00
Kevin Ballard
cc42b61936 Handle fallout in io::net::addrinfo, io::process, and rt::rtio
API Changes:

- get_host_addresses() returns IoResult<Vec<IpAddr>>
- Process.extra_io is Vec<Option<io::PipeStream>>
2014-05-08 12:06:22 -07:00
Alex Crichton
426d022732 std: Ignore a flaky test on freebsd
This test runs successfully manually, but the bots are having trouble getting
this test to pass. Ignore it on freebsd for now.
2014-05-08 11:08:57 -07:00
Alex Crichton
f83d4f060a std: Mark timeout methods experimental
This was intended as part of the I/O timeouts commit, but it was mistakenly
forgotten. The type of the timeout argument is not guaranteed to remain constant
into the future.
2014-05-08 01:45:08 -07:00
Alex Crichton
8e95302181 native: Implement timeouts for windows pipes
This is the last remaining networkig object to implement timeouts for. This
takes advantage of the CancelIo function and the already existing asynchronous
I/O functionality of pipes.
2014-05-07 23:29:35 -07:00
Alex Crichton
e27f27c858 std: Add I/O timeouts to networking objects
These timeouts all follow the same pattern as established by the timeouts on
acceptors. There are three methods: set_timeout, set_read_timeout, and
set_write_timeout. Each of these sets a point in the future after which
operations will time out.

Timeouts with cloned objects are a little trickier. Each object is viewed as
having its own timeout, unaffected by other objects' timeouts. Additionally,
timeouts do not propagate when a stream is cloned or when a cloned stream has
its timeouts modified.

This commit is just the public interface which will be exposed for timeouts, the
implementation will come in later commits.
2014-05-07 23:27:01 -07:00
bors
e0fcb4eb3d auto merge of #13964 : alexcrichton/rust/more-buffers, r=brson
This will allow methods like read_line() on RefReader, LimitReader, etc.
2014-05-07 20:36:37 -07:00
bors
ab22d99e73 auto merge of #13751 : alexcrichton/rust/io-close-read, r=brson
Two new methods were added to TcpStream and UnixStream:

    fn close_read(&mut self) -> IoResult<()>;
    fn close_write(&mut self) -> IoResult<()>;

These two methods map to shutdown()'s behavior (the system call on unix),
closing the reading or writing half of a duplex stream. These methods are
primarily added to allow waking up a pending read in another task. By closing
the reading half of a connection, all pending readers will be woken up and will
return with EndOfFile. The close_write() method was added for symmetry with
close_read(), and I imagine that it will be quite useful at some point.

Implementation-wise, librustuv got the short end of the stick this time. The
native versions just delegate to the shutdown() syscall (easy). The uv versions
can leverage uv_shutdown() for tcp/unix streams, but only for closing the
writing half. Closing the reading half is done through some careful dancing to
wake up a pending reader.

As usual, windows likes to be different from unix. The windows implementation
uses shutdown() for sockets, but shutdown() is not available for named pipes.
Instead, CancelIoEx was used with same fancy synchronization to make sure
everyone knows what's up.

cc #11165
2014-05-07 17:21:37 -07:00
Alex Crichton
ec9ade938e std: Add close_{read,write}() methods to I/O
Two new methods were added to TcpStream and UnixStream:

    fn close_read(&mut self) -> IoResult<()>;
    fn close_write(&mut self) -> IoResult<()>;

These two methods map to shutdown()'s behavior (the system call on unix),
closing the reading or writing half of a duplex stream. These methods are
primarily added to allow waking up a pending read in another task. By closing
the reading half of a connection, all pending readers will be woken up and will
return with EndOfFile. The close_write() method was added for symmetry with
close_read(), and I imagine that it will be quite useful at some point.

Implementation-wise, librustuv got the short end of the stick this time. The
native versions just delegate to the shutdown() syscall (easy). The uv versions
can leverage uv_shutdown() for tcp/unix streams, but only for closing the
writing half. Closing the reading half is done through some careful dancing to
wake up a pending reader.

As usual, windows likes to be different from unix. The windows implementation
uses shutdown() for sockets, but shutdown() is not available for named pipes.
Instead, CancelIoEx was used with same fancy synchronization to make sure
everyone knows what's up.

cc #11165
2014-05-07 17:18:07 -07:00
Alex Crichton
0d8f5fa618 core: Move Option::expect to libstd from libcore
See #14008 for more details
2014-05-07 08:17:32 -07:00
Alex Crichton
d4b5d82a33 core: Add unwrap()/unwrap_err() methods to Result
These implementations must live in libstd right now because the fmt module has
not been migrated yet. This will occur in a later PR.

Just to be clear, there are new extension traits, but they are not necessary
once the std::fmt module has migrated to libcore, which is a planned migration
in the future.
2014-05-07 08:16:14 -07:00
Alex Crichton
9bae6ec828 core: Inherit possible string functionality
This moves as much allocation as possible from teh std::str module into
core::str. This includes essentially all non-allocating functionality, mostly
iterators and slicing and such.

This primarily splits the Str trait into only having the as_slice() method,
adding a new StrAllocating trait to std::str which contains the relevant new
allocation methods. This is a breaking change if any of the methods of "trait
Str" were overriden. The old functionality can be restored by implementing both
the Str and StrAllocating traits.

[breaking-change]
2014-05-07 08:16:14 -07:00
Alex Crichton
678b1659f9 std: Implement the Buffer trait for some wrappers
This will allow methods like read_line() on RefReader, LimitReader, etc.
2014-05-07 08:11:19 -07:00
bors
ef6daf9935 auto merge of #13958 : pcwalton/rust/detilde, r=pcwalton
for `~str`/`~[]`.

Note that `~self` still remains, since I forgot to add support for
`Box<self>` before the snapshot.

r? @brson or @alexcrichton or whoever
2014-05-07 05:16:48 -07:00
Patrick Walton
090040bf40 librustc: Remove ~EXPR, ~TYPE, and ~PAT from the language, except
for `~str`/`~[]`.

Note that `~self` still remains, since I forgot to add support for
`Box<self>` before the snapshot.

How to update your code:

* Instead of `~EXPR`, you should write `box EXPR`.

* Instead of `~TYPE`, you should write `Box<Type>`.

* Instead of `~PATTERN`, you should write `box PATTERN`.

[breaking-change]
2014-05-06 23:12:54 -07:00
bors
2dcbad5bc4 auto merge of #13754 : alexcrichton/rust/net-experimental, r=brson
The underlying I/O objects implement a good deal of various options here and
there for tuning network sockets and how they perform. Most of this is a relic
of "whatever libuv provides", but these options are genuinely useful.

It is unclear at this time whether these options should be well supported or
not, or whether they have correct names or not. For now, I believe it's better
to expose the functionality than to not, but all new methods are added with
an #[experimental] annotation.
2014-05-06 22:01:43 -07:00
Aaron Turon
8d1d7d9b5f Change std::io::FilePermission to a typesafe representation
This patch changes `std::io::FilePermissions` from an exposed `u32`
representation to a typesafe representation (that only allows valid
flag combinations) using the `std::bitflags`, thus ensuring a greater
degree of safety on the Rust side.

Despite the change to the type, most code should continue to work
as-is, sincde the new type provides bit operations in the style of C
flags. To get at the underlying integer representation, use the `bits`
method; to (unsafely) convert to `FilePermissions`, use
`FilePermissions::from_bits`.

Closes #6085.

[breaking-change]
2014-05-05 15:24:36 -07:00
bors
1b5bbbf877 auto merge of #13865 : alexcrichton/rust/issue-13861, r=brson
Previously, windows was using the CREATE_NEW flag which fails if the file
previously existed, which differed from the unix semantics. This alters the
opening to use the OPEN_ALWAYS flag to mirror the unix semantics.

Closes #13861
2014-05-04 18:36:43 -07:00
Brian Anderson
a5be12ce7e Replace most ~exprs with 'box'. #11779 2014-05-02 23:00:58 -07:00
Jorge Aparicio
e4bf643b99 Fix a/an typos 2014-05-01 20:02:11 -05:00
Alex Crichton
8375a22b16 native: Always open a file with Open/Write modes
Previously, windows was using the CREATE_NEW flag which fails if the file
previously existed, which differed from the unix semantics. This alters the
opening to use the OPEN_ALWAYS flag to mirror the unix semantics.

Closes #13861
2014-04-30 11:37:01 -07:00
m-r-r
a7b8a13e14 Added missing values in std::io::standard_error() 2014-04-27 14:45:28 +02:00
Alex Crichton
022a01d40c std: Add experimental networking methods
The underlying I/O objects implement a good deal of various options here and
there for tuning network sockets and how they perform. Most of this is a relic
of "whatever libuv provides", but these options are genuinely useful.

It is unclear at this time whether these options should be well supported or
not, or whether they have correct names or not. For now, I believe it's better
to expose the functionality than to not, but all new methods are added with
an #[experimental] annotation.
2014-04-26 10:22:37 -07:00
Aaron Turon
3200ce5a2e clarify docs for std:io::fs::Path::{is_dir,is_file,exists}; add lstat
Clarifies the interaction of `is_dir`, `is_file` and `exists` with
symbolic links.  Adds a convenience `lstat` function alongside of
`stat`.  Removes references to conditions.

Closes issue #12583.
2014-04-25 15:02:09 -07:00
Alex Crichton
6328f7c199 std: Add timeouts to unix connect/accept
This adds support for connecting to a unix socket with a timeout (a named pipe
on windows), and accepting a connection with a timeout. The goal is to bring
unix pipes/named sockets back in line with TCP support for timeouts.

Similarly to the TCP sockets, all methods are marked #[experimental] due to
uncertainty about the type of the timeout argument.

This internally involved a good bit of refactoring to share as much code as
possible between TCP servers and pipe servers, but the core implementation did
not change drastically as part of this commit.

cc #13523
2014-04-24 16:24:09 -07:00
Aaron Turon
b536d2bb76 fix O(n^2) perf bug for std::io::fs::walk_dir
The `walk_dir` iterator was simulating a queue using a vector (in particular, using `shift`),
leading to O(n^2) performance. Since the order was not well-specified (see issue #13411),
the simplest fix is to use the vector as a stack (and thus yield a depth-first traversal).
This patch does exactly that.  It leaves the order as originally specified -- "some top-down
order" -- and adds a test to ensure a top-down traversal.

Note that the underlying `readdir` function does not specify any particular order, nor
does the system call it uses.

Closes #13411.
2014-04-24 10:34:13 -07:00
bors
3d05e7f9cd auto merge of #13688 : alexcrichton/rust/accept-timeout, r=brson
This adds experimental support for timeouts when accepting sockets through
`TcpAcceptor::accept`. This does not add a separate `accept_timeout` function,
but rather it adds a `set_timeout` function instead. This second function is
intended to be used as a hard deadline after which all accepts will never block
and fail immediately.

This idea was derived from Go's SetDeadline() methods. We do not currently have
a robust time abstraction in the standard library, so I opted to have the
argument be a relative time in millseconds into the future. I believe a more
appropriate argument type is an absolute time, but this concept does not exist
yet (this is also why the function is marked #[experimental]).

The native support is built on select(), similarly to connect_timeout(), and the
green support is based on channel select and a timer.

cc #13523
2014-04-23 19:21:33 -07:00
Alex Crichton
e5d3e5180f std: Add support for an accept() timeout
This adds experimental support for timeouts when accepting sockets through
`TcpAcceptor::accept`. This does not add a separate `accept_timeout` function,
but rather it adds a `set_timeout` function instead. This second function is
intended to be used as a hard deadline after which all accepts will never block
and fail immediately.

This idea was derived from Go's SetDeadline() methods. We do not currently have
a robust time abstraction in the standard library, so I opted to have the
argument be a relative time in millseconds into the future. I believe a more
appropriate argument type is an absolute time, but this concept does not exist
yet (this is also why the function is marked #[experimental]).

The native support is built on select(), similarly to connect_timeout(), and the
green support is based on channel select and a timer.

cc #13523
2014-04-23 19:07:31 -07:00
bors
6beb376b5c auto merge of #13686 : alexcrichton/rust/issue-12224, r=nikomatsakis
This alters the borrow checker's requirements on invoking closures from
requiring an immutable borrow to requiring a unique immutable borrow. This means 
that it is illegal to invoke a closure through a `&` pointer because there is no 
guarantee that is not aliased. This does not mean that a closure is required to
be in a mutable location, but rather a location which can be proven to be
unique (often through a mutable pointer).
                                                                                 
For example, the following code is unsound and is no longer allowed:             
                                                                                 
    type Fn<'a> = ||:'a;                                                         
                                                                                 
    fn call(f: |Fn|) {                                                           
        f(|| {                                                                   
            f(|| {})                                                             
        });                                                                      
    }                                                                            
                                                                                 
    fn main() {                                                                  
        call(|a| {                                                               
            a();                                                                 
        });                                                                      
    }                                                                            
                                                                                 
There is no replacement for this pattern. For all closures which are stored in
structures, it was previously allowed to invoke the closure through `&self` but
it now requires invocation through `&mut self`.

The standard library has a good number of violations of this new rule, but the
fixes will be separated into multiple breaking change commits.
                                                                                 
Closes #12224
2014-04-23 12:01:53 -07:00
Alex Crichton
823c7eee6a Fix other bugs with new closure borrowing
This fixes various issues throughout the standard distribution and tests.
2014-04-23 10:03:43 -07:00
bors
1ce0b98c7b auto merge of #13692 : vadimcn/rust/Win64-pre, r=alexcrichton
Stack unwinding doesn't work yet, so this won't pass a lot of tests.
2014-04-23 03:21:32 -07:00
Vadim Chugunov
f686e5ebff Fixed Win64 build 2014-04-22 18:08:06 -07:00
Alex Crichton
f1fb57a5cc native: Unlink unix socket paths on drop
This prevents unix sockets from remaining on the system all over the place, and
more closely mirrors the behavior of libuv and windows pipes.
2014-04-22 13:24:12 -07:00
Alex Crichton
3915e17cd7 std: Add an experimental connect_timeout function
This adds a `TcpStream::connect_timeout` function in order to assist opening
connections with a timeout (cc #13523). There isn't really much design space for
this specific operation (unlike timing out normal blocking reads/writes), so I
am fairly confident that this is the correct interface for this function.

The function is marked #[experimental] because it takes a u64 timeout argument,
and the u64 type is likely to change in the future.
2014-04-19 00:47:14 -07:00
Richo Healey
919889a1d6 Replace all ~"" with "".to_owned() 2014-04-18 17:25:34 -07:00
Alex Crichton
7d3b0bf391 std: Make ~[T] no longer a growable vector
This removes all resizability support for ~[T] vectors in preparation of DST.
The only growable vector remaining is Vec<T>. In summary, the following methods
from ~[T] and various functions were removed. Each method/function has an
equivalent on the Vec type in std::vec unless otherwise stated.

* slice::OwnedCloneableVector
* slice::OwnedEqVector
* slice::append
* slice::append_one
* slice::build (no replacement)
* slice::bytes::push_bytes
* slice::from_elem
* slice::from_fn
* slice::with_capacity
* ~[T].capacity()
* ~[T].clear()
* ~[T].dedup()
* ~[T].extend()
* ~[T].grow()
* ~[T].grow_fn()
* ~[T].grow_set()
* ~[T].insert()
* ~[T].pop()
* ~[T].push()
* ~[T].push_all()
* ~[T].push_all_move()
* ~[T].remove()
* ~[T].reserve()
* ~[T].reserve_additional()
* ~[T].reserve_exect()
* ~[T].retain()
* ~[T].set_len()
* ~[T].shift()
* ~[T].shrink_to_fit()
* ~[T].swap_remove()
* ~[T].truncate()
* ~[T].unshift()
* ~str.clear()
* ~str.set_len()
* ~str.truncate()

Note that no other API changes were made. Existing apis that took or returned
~[T] continue to do so.

[breaking-change]
2014-04-18 10:06:24 -07:00
Huon Wilson
54ec04f1c1 Use the unsigned integer types for bitwise intrinsics.
Exposing ctpop, ctlz, cttz and bswap as taking signed i8/i16/... is just
exposing the internal LLVM names pointlessly (LLVM doesn't have "signed
integers" or "unsigned integers", it just has sized integer types
with (un)signed *operations*).

These operations are semantically working with raw bytes, which the
unsigned types model better.
2014-04-15 19:45:00 -07:00
Alex Crichton
c836ff4621 std: Impl Deref/DerefMut for a borrowed task 2014-04-15 19:45:00 -07:00
Manish Goregaokar
713e87526e Use new attribute syntax in python files in src/etc too (#13478) 2014-04-14 21:00:31 +05:30
bors
ab0d847277 auto merge of #13448 : alexcrichton/rust/rework-chan-return-values, r=brson
There are currently a number of return values from the std::comm methods, not
all of which are necessarily completely expressive:

 * `Sender::try_send(t: T) -> bool`
    This method currently doesn't transmit back the data `t` if the send fails
    due to the other end having disconnected. Additionally, this shares the name
    of the synchronous try_send method, but it differs in semantics in that it
    only has one failure case, not two (the buffer can never be full).

 * `SyncSender::try_send(t: T) -> TrySendResult<T>`
    This method accurately conveys all possible information, but it uses a
    custom type to the std::comm module with no convenience methods on it.
    Additionally, if you want to inspect the result you're forced to import
    something from `std::comm`.

 * `SyncSender::send_opt(t: T) -> Option<T>`
    This method uses Some(T) as an "error value" and None as a "success value",
    but almost all other uses of Option<T> have Some/None the other way

 * `Receiver::try_recv(t: T) -> TryRecvResult<T>`
    Similarly to the synchronous try_send, this custom return type is lacking in
    terms of usability (no convenience methods).

With this number of drawbacks in mind, I believed it was time to re-work the
return types of these methods. The new API for the comm module is:

    Sender::send(t: T) -> ()
    Sender::send_opt(t: T) -> Result<(), T>
    SyncSender::send(t: T) -> ()
    SyncSender::send_opt(t: T) -> Result<(), T>
    SyncSender::try_send(t: T) -> Result<(), TrySendError<T>>
    Receiver::recv() -> T
    Receiver::recv_opt() -> Result<T, ()>
    Receiver::try_recv() -> Result<T, TryRecvError>

The notable changes made are:

* Sender::try_send => Sender::send_opt. This renaming brings the semantics in
  line with the SyncSender::send_opt method. An asychronous send only has one
  failure case, unlike the synchronous try_send method which has two failure
  cases (full/disconnected).

* Sender::send_opt returns the data back to the caller if the send is guaranteed
  to fail. This method previously returned `bool`, but then it was unable to
  retrieve the data if the data was guaranteed to fail to send. There is still a
  race such that when `Ok(())` is returned the data could still fail to be
  received, but that's inherent to an asynchronous channel.

* Result is now the basis of all return values. This not only adds lots of
  convenience methods to all return values for free, but it also means that you
  can inspect the return values with no extra imports (Ok/Err are in the
  prelude). Additionally, it's now self documenting when something failed or not
  because the return value has "Err" in the name.

Things I'm a little uneasy about:

* The methods send_opt and recv_opt are not returning options, but rather
  results. I felt more strongly that Option was the wrong return type than the
  _opt prefix was wrong, and I coudn't think of a much better name for these
  methods. One possible way to think about them is to read the _opt suffix as
  "optionally".

* Result<T, ()> is often better expressed as Option<T>. This is only applicable
  to the recv_opt() method, but I thought it would be more consistent for
  everything to return Result rather than one method returning an Option.

Despite my two reasons to feel uneasy, I feel much better about the consistency
in return values at this point, and I think the only real open question is if
there's a better suffix for {send,recv}_opt.

Closes #11527
2014-04-12 12:21:58 -07:00
bors
b7e9306773 auto merge of #13458 : huonw/rust/doc-signatures, r=alexcrichton
Add more type signatures to the docs; tweak a few of them.

Someone reading the docs won't know what the types of various things
are, so this adds them in a few meaningful places to help with
comprehension.

cc #13423.
2014-04-11 12:01:44 -07:00
Huon Wilson
5b109a1754 Add more type signatures to the docs; tweak a few of them.
Someone reading the docs won't know what the types of various things
are, so this adds them in a few meaningful places to help with
comprehension.

cc #13423.
2014-04-11 23:10:22 +10:00
Liigo Zhuang
408f484b66 libtest: rename BenchHarness to Bencher
Closes #12640
2014-04-11 17:31:13 +08:00
Alex Crichton
545d4718c8 std: Make std::comm return types consistent
There are currently a number of return values from the std::comm methods, not
all of which are necessarily completely expressive:

  Sender::try_send(t: T) -> bool
    This method currently doesn't transmit back the data `t` if the send fails
    due to the other end having disconnected. Additionally, this shares the name
    of the synchronous try_send method, but it differs in semantics in that it
    only has one failure case, not two (the buffer can never be full).

  SyncSender::try_send(t: T) -> TrySendResult<T>
    This method accurately conveys all possible information, but it uses a
    custom type to the std::comm module with no convenience methods on it.
    Additionally, if you want to inspect the result you're forced to import
    something from `std::comm`.

  SyncSender::send_opt(t: T) -> Option<T>
    This method uses Some(T) as an "error value" and None as a "success value",
    but almost all other uses of Option<T> have Some/None the other way

  Receiver::try_recv(t: T) -> TryRecvResult<T>
    Similarly to the synchronous try_send, this custom return type is lacking in
    terms of usability (no convenience methods).

With this number of drawbacks in mind, I believed it was time to re-work the
return types of these methods. The new API for the comm module is:

  Sender::send(t: T) -> ()
  Sender::send_opt(t: T) -> Result<(), T>
  SyncSender::send(t: T) -> ()
  SyncSender::send_opt(t: T) -> Result<(), T>
  SyncSender::try_send(t: T) -> Result<(), TrySendError<T>>
  Receiver::recv() -> T
  Receiver::recv_opt() -> Result<T, ()>
  Receiver::try_recv() -> Result<T, TryRecvError>

The notable changes made are:

* Sender::try_send => Sender::send_opt. This renaming brings the semantics in
  line with the SyncSender::send_opt method. An asychronous send only has one
  failure case, unlike the synchronous try_send method which has two failure
  cases (full/disconnected).

* Sender::send_opt returns the data back to the caller if the send is guaranteed
  to fail. This method previously returned `bool`, but then it was unable to
  retrieve the data if the data was guaranteed to fail to send. There is still a
  race such that when `Ok(())` is returned the data could still fail to be
  received, but that's inherent to an asynchronous channel.

* Result is now the basis of all return values. This not only adds lots of
  convenience methods to all return values for free, but it also means that you
  can inspect the return values with no extra imports (Ok/Err are in the
  prelude). Additionally, it's now self documenting when something failed or not
  because the return value has "Err" in the name.

Things I'm a little uneasy about:

* The methods send_opt and recv_opt are not returning options, but rather
  results. I felt more strongly that Option was the wrong return type than the
  _opt prefix was wrong, and I coudn't think of a much better name for these
  methods. One possible way to think about them is to read the _opt suffix as
  "optionally".

* Result<T, ()> is often better expressed as Option<T>. This is only applicable
  to the recv_opt() method, but I thought it would be more consistent for
  everything to return Result rather than one method returning an Option.

Despite my two reasons to feel uneasy, I feel much better about the consistency
in return values at this point, and I think the only real open question is if
there's a better suffix for {send,recv}_opt.

Closes #11527
2014-04-10 21:41:19 -07:00
Alex Crichton
1f2c18a0af rustc: Don't allow priv use to shadow pub use
Previously, a private use statement would shadow a public use statement, all of
a sudden publicly exporting the privately used item. The correct behavior here
is to only shadow the use for the module in question, but for now it just
reverts the entire name to private so the pub use doesn't have much effect.

The behavior isn't exactly what we want, but this no longer has backwards
compatibility hazards.
2014-04-10 15:22:01 -07:00