Title: This Week in Rust 41 Date: 2014-03-15 23:33 Category: This Week in Rust Hello and welcome to another issue of *This Week in Rust*! [Rust](http://rust-lang.org) is a systems language pursuing the trifecta: safe, concurrent, and fast. This is a weekly summary of its progress and community. Want something mentioned? [Send me an email!](mailto:corey@octayn.net?subject=This%20Week%20in%20Rust%20Suggestion) Want to get involved? [We love contributions](https://github.com/mozilla/rust/wiki/Note-guide-for-new-contributors). # What's cooking on master? 66 pull requests were merged this week. ## Breaking Changes - Some more string methods [now return Option](https://github.com/mozilla/rust/pull/12797). - Matching on `~str` [has been removed](https://github.com/mozilla/rust/pull/12756). - IO iterators [now yield IoResult](https://github.com/mozilla/rust/pull/12414). - The channel types and constructor [have been renamed](https://github.com/mozilla/rust/pull/12815). `Chan` is now `Sender`, `Port` is now `Receiver`, and `Chan::new` is now `std::comm::channel`. - `std::cmp::{min, max}` [now require TotalOrd](https://github.com/mozilla/rust/pull/12869). For floats, use `a.min(b)`. - The handling of `cfg(not(a, b))` [has changed slightly](https://github.com/mozilla/rust/pull/12893). - `libextra` [has finally been purged](https://github.com/mozilla/rust/pull/12896). ## Other Changes - Another great PR from the illustrious ktt3ja, the compiler [will now give suggestions](https://github.com/mozilla/rust/pull/12238) on how to fix lifetime woes. This is an awesome usability improvement. - Implementations of `Deref` and `DerefMut` [are now considered](https://github.com/mozilla/rust/pull/12610) for automatic dereferencing. - Partial type hints [are now implemented](https://github.com/mozilla/rust/pull/12764), but not at the item level (in function returns etc). The eventual goal is to have `some_iter.collect::>()` be possible. - There is a [new guide](http://static.rust-lang.org/doc/master/guide-unsafe.html) for "low level and unsafe code". [PR](https://github.com/mozilla/rust/pull/12887). - There is now a lint for [uses of `~[T]`](https://github.com/mozilla/rust/pull/12861). It's very verbose. The replacement for `~[T]`, as recommended by the lint, is `std::vec_ng::Vec`. It implements almost everything `~[T]` does. - `HashMap` [has been reimplemented](https://github.com/mozilla/rust/pull/12081) to use [Robin Hood hashing](http://codecapsule.com/2013/11/11/robin-hood-hashing/). It's now much more faster, and uses less space. - Support for basic backtracing [has been reimplemented](https://github.com/mozilla/rust/pull/12602). - `char` [now has simple case folding](https://github.com/mozilla/rust/pull/12561). That is, basic locale-ignorant case conversion. - Inline assembly [now supports the `+` modifier](https://github.com/mozilla/rust/pull/12798). ## New Contributors - Adolfo Ochagavía - Clark Gaebel - Peter Marheine - Piotr Czarnecki - Piotr Zolnierek - Robert Gawdzik # Weekly Meeting The [weekly meeting](https://github.com/mozilla/rust/wiki/Meeting-weekly-2014-03-11) discussed the new hashmap, destructuring the `self` argument, partial type hints, coercion of returned values, as well as the requirements of unsafe pointers and the continued existence of `*mut`. # This Week in Servo Servo is a web browser engine written in Rust and is one of the primary test cases for the Rust language. In the last two weeks, we landed 56 PRs. ## Notable additions - Patrick Walton made fixes to ACID in [#1905](https://github.com/mozilla/servo/pull/1905) - Along with about 20 other PRs, ms2ger brought WindowTimers up to date with the spec in [#1890](https://github.com/mozilla/servo/pull/1890) - Pradeep Kumar implemented `position:absolute` in [#1681](https://github.com/mozilla/servo/pull/1681) and fixed up relative positioning in [#1808](https://github.com/mozilla/servo/pull/1808) - Bill Yang fixed up our instructions for installation on Ubuntu Linux in [#1881](https://github.com/mozilla/servo/pull/1881) - Bruno Abinader fixed up HTMLCollection in [#1838](https://github.com/mozilla/servo/pull/1838) - Isabelle Carter ensured that children of `position:fixed` items make it into the correct DisplayList in [#1832](https://github.com/mozilla/servo/pull/1832) - Manish Goregaokar made `getElementsByName` return a `NodeList` in [#1756](https://github.com/mozilla/servo/pull/1756) - Keegan McAllister cleaned up our reftest harness and made them test both the CPU and GPU rendering paths in [#1804](https://github.com/mozilla/servo/pull/1804) ## New contributors - Bill Yang (analyst74) - Manish Goregaokar (manishearth) ## Meetings and Notes At this week's [meeting](https://github.com/mozilla/servo/wiki/Meeting-2014-03-10), we discussed HTML parsing, embedding, writing modes, the ACID2 burndown, and the Rust upgrade. # RFCs [We have a new RFC process](https://github.com/rust-lang/rfcs/blob/master/active/0001-rfc-process.md)! Every week I'll list the new RFCs and RFCs that have been accepted. Contributing to the discussions around these RFCs is the easiest way to drive the design of Rust. As an aside, I will no longer include any RFCs in the "Announcements" section that are not sent to the RFC repository. - [Private Fields by Default](https://github.com/rust-lang/rfcs/pull/1) - [Rearchitecting the attribute-usage lint](https://github.com/rust-lang/rfcs/pull/3) - [Unified Function Call Syntax](https://github.com/rust-lang/rfcs/pull/4) - [Virtual Structs](https://github.com/rust-lang/rfcs/pull/5) - [Add OsUnknown as a target operating system](https://github.com/rust-lang/rfcs/pull/7) - [Redesign Compiler Intrinsics](https://github.com/rust-lang/rfcs/pull/8) - ["Fat Objects" for DSTs](https://github.com/rust-lang/rfcs/pull/9), an alternative to "Virtual Structs". # Project Updates [rust-bencode](https://github.com/arjantop/rust-bencode), a pure Rust implementation of Bencode encoding. [Bencode](http://en.wikipedia.org/wiki/Bencode) is used primarily in the BitTorrent protocol. This implementation leverages the `serialize` crate for automatic Encodable/Decodable implementation as well as custom, more flexible FromBencode/ToBencode traits. [Lazily initialized statics v0.2](https://gist.github.com/Kimundi/8782487). This makes safe use of statics for types which require runtime initialization almost trivial. It utilizes the recent overloadable deref to do optional initialization before returning the reference to the wrapped type. It's an example that the right amount of abstractions, but syntactic (macros) and semantic (operator overloading) can reduce boilerplate for a more pleasant experience. [Racer](https://github.com/phildawes/racer) - code completion for Rust. This project is in its early stages, but can already do a fair bit of useful completion. It is not using the parser (libsyntax) or compiler (librustc), so it will likely always be inaccurate in some respect. Nevertheless, this may prove to be an incredibly useful tool. [QuickCheck for Rust](https://github.com/BurntSushi/quickcheck). This has some seriously great docs. QuickCheck, originally from Haskell, is a way of doing property-based testing. You describe certain properties your code should have and it generates random inputs, trying to find inputs that violate those properties. This is a modern, featureful port of QuickCheck and hopefully gets even more useful as time goes on. The [coreutils port](https://github.com/uutils/coreutils) is still alive and making progress. 32 out of 119 programs are implemented. This is a great project to contribute to if you want a relatively self-contained, goal-oriented task. It's great practice both for learning Unix* (some of these utilities are quirky or not-frequently-used) and Rust. \* Well, specifically GNU, which as we all know, [ain't Unix](https://en.wikipedia.org/wiki/GNU). # Other Announcements - [Under The Hood Of Mozilla's New Multi-Core Browser And The Open Source Language That Powers It](http://www.fastcolabs.com/3027664/under-the-hood-of-mozillas-new-multi-core-browser-and-the-open-source-language-that-powers-i) - [Bay Area Rust, March 2014 Meetup](http://www.reddit.com/r/rust/comments/20ct5c/march_meetup_live_stream_link_oss_parallel_layout/) - [Writing an OS in Rust in tiny steps](http://www.reddit.com/r/rust/comments/20aj03/writing_an_os_in_rust_in_tiny_steps_steps_15/) - ["Virtual fn" is a bad idea](http://thread.gmane.org/gmane.comp.lang.rust.devel/8878)