Go to file
Alex Crichton 6227357513 std: Stabilize the std::fmt module
This commit performs a final stabilization pass over the std::fmt module,
marking all necessary APIs as stable. One of the more interesting aspects of
this module is that it exposes a good deal of its runtime representation to the
outside world in order for `format_args!` to be able to construct the format
strings. Instead of hacking the compiler to assume that these items are stable,
this commit instead lays out a story for the stabilization and evolution of
these APIs.

There are three primary details used by the `format_args!` macro:

1. `Arguments` - an opaque package of a "compiled format string". This structure
   is passed around and the `write` function is the source of truth for
   transforming a compiled format string into a string at runtime. This must be
   able to be constructed in stable code.

2. `Argument` - an opaque structure representing an argument to a format string.
   This is *almost* a trait object as it's just a pointer/function pair, but due
   to the function originating from one of many traits, it's not actually a
   trait object. Like `Arguments`, this must be constructed from stable code.

3. `fmt::rt` - this module contains the runtime type definitions primarily for
   the `rt::Argument` structure. Whenever an argument is formatted with
   nonstandard flags, a corresponding `rt::Argument` is generated describing how
   the argument is being formatted. This can be used to construct an
   `Arguments`.

The primary interface to `std::fmt` is the `Arguments` structure, and as such
this type name is stabilize as-is today. It is expected for libraries to pass
around an `Arguments` structure to represent a pending formatted computation.

The remaining portions are largely "cruft" which would rather not be stabilized,
but due to the stability checks they must be. As a result, almost all pieces
have been renamed to represent that they are "version 1" of the formatting
representation. The theory is that at a later date if we change the
representation of these types we can add new definitions called "version 2" and
corresponding constructors for `Arguments`.

One of the other remaining large questions about the fmt module were how the
pending I/O reform would affect the signatures of methods in the module. Due to
[RFC 526][rfc], however, the writers of fmt are now incompatible with the
writers of io, so this question has largely been solved. As a result the
interfaces are largely stabilized as-is today.

[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0526-fmt-text-writer.md

Specifically, the following changes were made:

* The contents of `fmt::rt` were all moved under `fmt::rt::v1`
* `fmt::rt` is stable
* `fmt::rt::v1` is stable
* `Error` is stable
* `Writer` is stable
* `Writer::write_str` is stable
* `Writer::write_fmt` is stable
* `Formatter` is stable
* `Argument` has been renamed to `ArgumentV1` and is stable
* `ArgumentV1::new` is stable
* `ArgumentV1::from_uint` is stable
* `Arguments::new_v1` is stable (renamed from `new`)
* `Arguments::new_v1_formatted` is stable (renamed from `with_placeholders`)
* All formatting traits are now stable, as well as the `fmt` method.
* `fmt::write` is stable
* `fmt::format` is stable
* `Formatter::pad_integral` is stable
* `Formatter::pad` is stable
* `Formatter::write_str` is stable
* `Formatter::write_fmt` is stable
* Some assorted top level items which were only used by `format_args!` were
  removed in favor of static functions on `ArgumentV1` as well.
* The formatting-flag-accessing methods remain unstable

Within the contents of the `fmt::rt::v1` module, the following actions were
taken:

* Reexports of all enum variants were removed
* All prefixes on enum variants were removed
* A few miscellaneous enum variants were renamed
* Otherwise all structs, fields, and variants were marked stable.

In addition to these actions in the `std::fmt` module, many implementations of
`Show` and `String` were stabilized as well.

In some other modules:

* `ToString` is now stable
* `ToString::to_string` is now stable
* `Vec` no longer implements `fmt::Writer` (this has moved to `String`)

This is a breaking change due to all of the changes to the `fmt::rt` module, but
this likely will not have much impact on existing programs.

Closes #20661
[breaking-change]
2015-01-30 09:21:56 -08:00
man Update rustdoc man page 2015-01-17 11:45:59 -08:00
mk Merge remote-tracking branch 'rust-lang/master' 2015-01-25 22:14:06 -08:00
src std: Stabilize the std::fmt module 2015-01-30 09:21:56 -08:00
.gitattributes webfonts: proper fix 2014-07-08 20:29:36 +02:00
.gitignore gitignore: Add the autogenerated/downloaded unicode data files. 2014-08-03 17:32:53 +10:00
.gitmodules Use rust-installer for installation 2014-12-11 17:14:17 -08:00
.mailmap Update .mailmap 2014-10-23 23:01:31 +02:00
.travis.yml Allow travis to use newer-faster infrastructure for building. http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/ 2015-01-01 02:00:29 -05:00
AUTHORS.txt Correct Orpheus Lummis's email and name 2015-01-28 10:04:56 -05:00
configure Auto merge of #21582 - FlaPer87:rollup, r=brson 2015-01-25 13:33:18 +00:00
CONTRIBUTING.md discuss.rust-lang.org -> internals.rust-lang.org 2015-01-27 15:44:05 -08:00
COPYRIGHT update mit-license and copyright 2015-01-10 23:35:33 -05:00
LICENSE-APACHE Update license, add license boilerplate to most files. Remainder will follow. 2012-12-03 17:12:14 -08:00
LICENSE-MIT Bump LICENSE copyright year 2015-01-17 10:51:07 -05:00
Makefile.in Remove dead link from make tips 2015-01-12 17:12:05 -05:00
README.md Rollup merge of 21708 - brson:internals, r=huonw 2015-01-29 03:13:53 +05:30
RELEASES.md Link to http://rustbyexample.com/ 2015-01-09 08:25:42 +01:00

The Rust Programming Language

This is a compiler for Rust, including standard libraries, tools and documentation.

Quick Start

  1. Download a binary installer for your platform.
  2. Read The Rust Programming Language.
  3. Enjoy!

Note: Windows users can read the detailed using Rust on Windows notes on the wiki.

Building from Source

  1. Make sure you have installed the dependencies:

    • g++ 4.7 or clang++ 3.x
    • python 2.6 or later (but not 3.x)
    • GNU make 3.81 or later
    • curl
    • git
  2. Download and build Rust:

    You can either download a tarball or build directly from the repo.

    To build from the tarball do:

     $ curl -O https://static.rust-lang.org/dist/rustc-nightly-src.tar.gz
     $ tar -xzf rustc-nightly-src.tar.gz
     $ cd rustc-nightly
    

    Or to build from the repo do:

     $ git clone https://github.com/rust-lang/rust.git
     $ cd rust
    

    Now that you have Rust's source code, you can configure and build it:

     $ ./configure
     $ make && make install
    

    Note: You may need to use sudo make install if you do not normally have permission to modify the destination directory. The install locations can be adjusted by passing a --prefix argument to configure. Various other options are also supported, pass --help for more information on them.

    When complete, make install will place several programs into /usr/local/bin: rustc, the Rust compiler, and rustdoc, the API-documentation tool.

  3. Read The Rust Programming Language.

  4. Enjoy!

Building on Windows

To easily build on windows we can use MSYS2:

  1. Grab the latest MSYS2 installer and go through the installer.
  2. Now from the MSYS2 terminal we want to install the mingw64 toolchain and the other tools we need.
# choose one based on platform
$ pacman -S mingw-w64-i686-toolchain
$ pacman -S mingw-w64-x86_64-toolchain

$ pacman -S base-devel
  1. With that now start mingw32_shell.bat or mingw64_shell.bat from where you installed MSYS2 (i.e. C:\msys). Which one you choose depends on if you want 32 or 64 bit Rust.

  2. From there just navigate to where you have Rust's source code, configure and build it:

     $ ./configure
     $ make && make install
    

Notes

Since the Rust compiler is written in Rust, it must be built by a precompiled "snapshot" version of itself (made in an earlier state of development). As such, source builds require a connection to the Internet, to fetch snapshots, and an OS that can execute the available snapshot binaries.

Snapshot binaries are currently built and tested on several platforms:

  • Windows (7, 8, Server 2008 R2), x86 and x86-64 (64-bit support added in Rust 0.12.0)
  • Linux (2.6.18 or later, various distributions), x86 and x86-64
  • OSX 10.7 (Lion) or greater, x86 and x86-64

You may find that other platforms work, but these are our officially supported build environments that are most likely to work.

Rust currently needs about 1.5 GiB of RAM to build without swapping; if it hits swap, it will take a very long time to build.

There is a lot more documentation in the wiki.

Getting help and getting involved

The Rust community congregates in a few places:

License

Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.

See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.