MacRuby allows Ruby code to run on Mac OS X and access Cocoa APIs. It uses the Objective-C runtime, so Ruby classes can extend Cocoa frameworks like NSString and NSArray. This provides benefits like no GIL, multithreaded GC, and access to Cocoa features like Grand Central Dispatch and Core Animation. A microbenchmark showed MacRuby outperforming Ruby 1.8.7 and competing with Ruby 1.9.2 and JRuby for a Fibonacci sequence calculation. The document provides code examples and discusses pros and cons like smaller download size but some gem incompatibility. Contact info and links are given for learning more.

1. MacRuby
SHRUG 2011-02-22
Peter Lind @peter_lind

2. What?
• Ruby 1.9 on the Objective-C runtime
• Apple project with external contributors
• Ruby License

3. Why?
• Better runtime
• GC, JIT compilation, AOT compilation
• Cocoa integration
• Ruby classes extends NSString, NSArray
etc

4. How?
• macruby / macirb / macgem / macrake
• require ‘rubygems’
• framework ‘cocoa’

5. Benefits
• No GIL
• Multithreaded GC
• lib_dispatch
• Access to Cocoa APIs
• GrandCentral, Core Animation, Speech
Recognition, Core Location

6. Micro-benchmark
~ $ rvm use 1.8.7
info: Using ruby 1.8.7 p302
~ $ ruby -e "start = Time.now; def fib(inp) inp < 2 ? inp : fib(inp-1) + fib(inp-2); end; (1..30).each do |i| fib(i);
end; puts Time.now - start"
3.097749
~ $ rvm use 1.9.2
info: Using ruby 1.9.2 p0
~ $ ruby -e "start = Time.now; def fib(inp) inp < 2 ? inp : fib(inp-1) + fib(inp-2); end; (1..30).each do |i| fib(i);
end; puts Time.now - start"
0.553159
~ $ rvm use jruby
info: Using jruby 1.5.2
~ $ ruby -e "start = Time.now; def fib(inp) inp < 2 ? inp : fib(inp-1) + fib(inp-2); end; (1..30).each do |i| fib(i);
end; puts Time.now - start"
0.692
~ $ macruby --version
MacRuby 0.8 (ruby 1.9.2) [universal-darwin10.0, x86_64]
~ $ macruby -e "start = Time.now; def fib(inp) inp < 2 ? inp : fib(inp-1) + fib(inp-2); end; (1..30).each do |i| fib
(i); end; puts Time.now - start"
0.19616

7. Demo

8. Ruby vs Objective-C
main_window_controller.rb
class MainWindowController < NSController
attr_accessor :url, :button
def start_stop(sender)
#implementation
end
MainWindowController.h MainWindowController.m
@interface DemoTakeTwoViewController : NSController { #import "DemoTakeTwoViewController.h"
UITextField *url;
UIButton *button; @implementation MainWindowController
}
@synthesize url;
@property (nonatomic, retain) IBOutlet UITextField @synthesize button;
*url;
@property (nonatomic, retain) IBOutlet UIButton - (IBAction)startStop {
*button; //implementation
}
- (IBAction)startStop;

9. • Pro
• Mac AppStore
• Scratch your own itch
• Fast
• Test Objective-C with RSpec
• Call into C or Obj-C code
• Con
• 50 MB download penalty
• Some gems not working (yet)
• iOS

10. Sounds like fun?
• http://macruby.org
• /Developer/Examples/Ruby/MacRuby
• http://macruby.labs.oreilly.com
• http://developer.apple.com
• git://github.com/peterlind/Hello-SHRUG.git