MacRubyWhat is it?

and why should you care?

Presented by: Joshua Ballanco

A bit about me...

• Using Ruby since 2004 (didn’t discover Rails until 2006)

• Worked for Apple 2006-2010 (Fifth Ave store & HQ in Cupertino)

• Now at Patch (just completed a migration to Ruby 1.9)

• MacRuby Core Team member

Overview• Practical MacRuby

• How is MacRuby different?

• Working with Cocoa

• Compiled Ruby!

• Make your millions on the App store

• Nuts & Bolts

• GC

• Regular Expression Engine

• Hash method syntax

• LLVM & other Hacking

• GCD

What is MacRuby?

What is MacRuby?

What is MacRuby?

What is MacRuby?

What is MacRuby?

• http://www.macruby.org

• http://www.macruby.org/files/

• http://www.macruby.org/files/nightlies/

• Available from RVM (but not recommended)

• Source now located at GitHub!

https://github.com/MacRuby/MacRuby

What is MacRuby?

• Compiling MacRuby:

• Need LLVM (see the README; brew install llvm)

• rake ; sudo rake install

• Bugs – https://www.macruby.org/trac/report

• MacRuby-devel mailing list

• @macruby, #macruby

No Really, What is MacRuby?

No Really, What is MacRuby?

A language with:

• Dynamic typing

• Objects everywhere

• Method calls via sending messages

• Automatic generation of accessors

• Methods can be added to classes at runtime

• Garbage Collection

• Closures

No Really, What is MacRuby?

A language with:

• Dynamic typing

• Objects everywhere

• Method calls via sending messages

• Automatic generation of accessors

• Methods can be added to classes at runtime

• Garbage Collection

• Closures

...called Objective-C

Ruby Syntax

Ruby Syntax

ParserMRI’s parse.y

Ruby Syntax

ParserMRI’s parse.y

CompilerRoxorCompiler <C++>

Ruby Syntax

ParserMRI’s parse.y

CompilerRoxorCompiler <C++>

VM (sans GVL)RoxorVM & RoxorCore <C++>

Ruby Syntax

ParserMRI’s parse.y

CompilerRoxorCompiler <C++>

VM (sans GVL)RoxorVM & RoxorCore <C++>

LLVM (with JIT)

Ruby Syntax

ParserMRI’s parse.y

CompilerRoxorCompiler <C++>

VM (sans GVL)RoxorVM & RoxorCore <C++>

LLVM (with JIT)

Ruby Syntax

ParserMRI’s parse.y

CompilerRoxorCompiler <C++>

VM (sans GVL)RoxorVM & RoxorCore <C++>

LLVM (with JIT)

Objective-C Runtime

Integrating with Cocoa

• Bridge Support (please download preview 3 from the “files” page)

• gen_bridge_metadata reads header files and generates XML descriptions of types and method signatures

• MacRuby uses BS files to construct calls and access constants and types

• framework “Foundation”

Integrating with Cocoa

• String, Array, Hash, are members of the NSString, NSArray, and NSDictionary class clusters

• Caution: NSString, NSArray, and NSDictionary will lie to you!

• Time is implemented as a subclass of NSDate

Demo

A Ruby You Can Compile

• macrubyc

• Advantages:

• Faster startup, faster runtime (in most cases)

• Don’t distribute the source!

• Disadvantages:

• ?

• ...some bugs

A Ruby You Can Compile

• -c → Compile and assemble; good for multistage builds

• -C → Compile, assemble, and link creating an *.rbo

• Can also create stand-alone executables and entire “*.framework”s (experimental)

Demo

I wanna be an App store billionaire...

• Downloads contain Xcode templates (mostly work in Xcode 4)

• Integration with Interface Builder

• macruby_deploy

• Includes BS files

• Unpacks Gems

• Compiles source

I wanna be an App store billionaire...

I wanna be an App store billionaire...

QuickAlarm

Briquette

Timey

Zero2Nine

MacRuby Nuts & Bolts

Garbage Collector:libauto

• Yet another open source project from Apple

• The GC for Obj-C

• Based on write barriers

• scanning, conservative, generational, multi-threaded garbage collector...

• ...unfortunately...slow

Garbage Collector:the Next Generation(?)

• Ruby does A LOT of allocations

• Nice to not have to stop the world, but...

• Write barriers are slow

• Maybe ref counting?

• Maybe MRI’s collector isn’t so bad after all...

RegExps:ICU

• Oniguruma is not (real thread) thread safe

• ICU is

• thread safe

• Unicode compatible

• not as crazy feature-full as Oniguruma

• There are some bugs...but honestly, stop doing that with RegExps!!!

Hash method syntax

• Ruby 1.9’s hash syntax with Symbol keys:a = { foo: 1, bar: 2, baz: “Hello, world” }

• ...looks a bit like:

[@”Hello, world” rangeOfString:@”ello” options: NSCaseInsensitiveSearch]

• Let’s go with that!

Hash method syntax

• MacRuby turns method calls with hash arguments into SEL

• MacRuby turns method definitions with hash lists into SEL

• MacRuby can call Objective-C

• Objective-C can call MacRuby, but when possible you should use:[[MacRuby sharedRuntime] performRubySelector:@”foo”]

LLVM, JIT, and Hacking

• LLVM provides optimizations

• LLVM provides JIT utilities (kinda slow)

• MacRuby can emit LLVM...VM_DUMP_IR=1 macruby -e "def foo; puts 'hello'; end; foo"

• Find other neat tricks in HACKING.rdoc

Demo

GCD & The Future

GCD

• MacRuby can tap directly into GCD

• Dispatch module:

• Dispatch::Queue

• Dispatch::Group

• Dispatch::Source

• Dispatch Gem too!

GCD

• Dispatch is a powerful tool for concurrent programming

• Example: ControlTower

• MacRuby Rack-based server

• Uses GCD to handle requets

• Accomplishes in 1 line what takes Thin/EventMachine > 6000 lines of C++ & Ruby

GCD

GCD

• Can we make GCD work in MRI?

• JRuby thinks they can make it work...

https://github.com/headius/jcd

• GCD is Multithreaded Programming, Ruby Style

Who Is MacRuby?• Laurent Sansonetti

• Vincent Isambart

• Eloy Durán

• Matt Aimonetti

• Joshua Ballanco

• Thibault Martin-Lagardette

• Watson

• Takao Kouji

• Mark Rada

• You?

Thank you!

http://ofps.oreilly.com/titles/9781449380373/