2013-07-13-this-week-in-rust.markdown

Title: This Week in Rust 6 Date: 2013-07-13 16:07 Category: This Week in Rust

Hello and welcome to the sixth issue of This Week in Rust, a weekly overview of Rust and its community.

What's cooking on master?

Issue churn this week was -17! A total of 63 PRs were merged this week, twice as many as last week. Not bad!

Breaking changes

• The task local storage (TLS) API was cleaned up (there's still one PR in the queue that finishes it up).
• DList was modernized.
• extra::json now uses Iterator<char> rather than a @Reader
• Various free-standing functions in f32 etc were removed
• ref bindings in irrefutable patterns has been tightened up. This potentially fixes and breaks code. It's breaking because the compiler now rejects incorrect programs that it did not before.
• str no longer encodes invalid utf-8.
• extra::rope was removed
• extra::net_ip and so on were removed. They were redundant names for extra::net::ip and such
• Iterator::size_hint's lower bound is no longer an Option

Notable compiler additions, bugfixes, and cleanup

• Unnecessary basic blocks were removed. This makes for much easier to read unoptimized IR.
• Use of *int/*uint is now properly warned in FFI functions.
• More default method fixes.
• A needless copy was removed from immediate values (I'm pretty sure LLVM optimized it away when optimizations were on, not positive).
• A lint for overqualified names was added.
• SIMD arithmetic was implemented.
• A graph abstraction and CFG was introduced, to unify how the various pieces of the compiler use graphs.
• The maximum lifetime of stack closures is now constrained. Not quite sure what that means, but it fixes a segfault.
• repr doesn't infinite loop on zero-sized structs (ie, unit structs).
• Type parameter pretty printing was fixed, it now prints the type name rather than 'a and 'b and soforth.
• mut in default method arguments is now allowed.
• IR for calls with immediate return values was improved.
• Exchange allocation headers (ie, the headers on ~T) were removed. This was a heroic effort by strcat and Luqman.
• -Z trans-stats now reports perf-function statistics
• Scopes were decoupled from LLVM basic blocks, improving unoptimized builds, and allowing more things in optimized builds to be inlined.
• An infinite loop when recursively including modules was fixed.
• An ICE involving struct-like enum variants was fixed.
• The buildsystem cleans up old libraries when it needs to.
• A bunch of managed boxes were removed from the AST.

Notable library additions, bugfixes, and cleanup

• print! and println! macros were added (though #7779 renames them).
• Ord now uses default methods, allowing you to get default implementations for everything but lt.
• extra::Bitv now takes &[bool] rather than ~[uint].
• x64 now uses large stacks (4 MiB) by default.
• is_utf8 is now 22% faster
• Metrics reporting and ratcheting was added to the test harness.
• A DoubleEndedIterator was added.
• A mut_split method was added to partition a &mut [T] into two pieces.
• We now have pointer arithmetic.
• A month's work of runtime work landed.
• A safe, cross-platform mmap wrapper was added.
• SmallIntMap and SmallIntSet have external iterators.
• JSON parsing got 93% faster
• Deque got a good cleanup and speedup.
• vec now implements pop_opt and shift_opt methods.
• A peek_ adaptor was added, which calls a closure on ever item before returning it. Mostly useful for debugging your iterators.

Documentation etc

• vim improvements landed.
• po4a support for translation was added.
• libc::c_void is better documented.
• Man pages for all the tools are now included.
• The iterator tutorial was extended.

Meetings

The Tuesday meeting was all about split stacks and FFI. It's complex and above my ability to summarize, but from what I can tell no real consensus was made. But, it's the best enumeration of all the various issues surrounding split stacks that I've seen.

Discussion + Blog posts

From now on I'm going to just link to the reddit thread if there is one, as it often has additional comments or insights.

• A simple, self-contained example of using a shared library
• Experimental Actor Library (reddit)
• Herb Sutter describes Rust (reddit)
• Philosophy and "for" loops (reddit)
• Reddit thread about the weekly meeting
• BZIP2 bindings (reddit)
• Proposal for an additional use case of the "in" keyword besides for loops (reddit)
• Technical Q&A on Servo (reddit)