Ruby 2.1 Overview

(For HoustonRB)

Transcript

1. @jwo
   Ruby 2.1
   

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2. @jwo
   `def` returns a
   method
   

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3. @jwo
   module Foo!
   def public_method!
   end!
   !
   def some_other_method!
   end!
   !
   private :some_other_method!
   !
   private!
   def a_private_method!
   end!
   end!
   !
   Foo.private_instance_methods!
   => [:some_other_method, :a_private_method]
   

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4. @jwo
   module Foo!
   def public_method!
   end!
   !
   private def some_other_method!
   end!
   !
   private def a_private_method!
   end!
   end!
   !
   Foo.private_instance_methods!
   => [:some_other_method, :a_private_method]
   

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5. @jwo
   Refinements
   Launched and the world did not end.
   

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6. @jwo
   module Permalinker!
   refine String do!
   def permalinkify!
   downcase.split.join("-")!
   end!
   end!
   end
   

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7. @jwo
   class Post!
   using Permalinker!
   !
   def initialize(title)!
   @title = title!
   end!
   !
   def permalink!
   @title.permalinkify!
   end!
   end
   

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8. @jwo
   "Refinements are not globally scoped".permalinkify!
   !
   !
   !
   NoMethodError: undefined method `permalinkify' for
   "Refinements are not globally scoped":String
   

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9. @jwo
   Restricted
   Keyword Args
   

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10. @jwo
    def order_tacos(type: 5, how_many: 'queso')!
    puts "Ordering #{how_many} #{type}"!
    end!
    !
    order_tacos type: "fajita_queso", how_many: 5
    in Ruby 2.0, you HAD to specify a
    default for type and how_many
    

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11. @jwo
    def order_tacos(type:, how_many:)!
    puts "Ordering #{how_many} #{type}"!
    end!
    !
    order_tacos type: "fajita_queso", how_many: 5!
    order_tacos type: “fajita_queso"!
    !
    => ArgumentError: missing keyword: how_many
    NO LONGER
    

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12. @jwo
    Restricted Generational
    Garbage Collector
    (RGENGC)
    

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13. @jwo
    ummm wat
    

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14. @jwo
    Ruby 1.8: Mark and Sweep
    http://tmm1.net/ruby21-rgengc/
    

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15. @jwo
    Ruby 1.9.3 “Lazy Sweep”
    http://tmm1.net/ruby21-rgengc/
    

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16. @jwo
    Ruby 2.0 bitmaps for copy-on-write
    safety
    http://tmm1.net/ruby21-rgengc/
    

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17. @jwo
    Ruby 2.1: OldGen and minor marking
    http://tmm1.net/ruby21-rgengc/
    

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18. @jwo
    Some Graphs!
    

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19. @jwo
    Some Little Stuff
    

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20. @jwo
    27r # => Rational(27/1)!
    1/2r # => Rational(1/2)!
    12+33i # => Complex(12,33)
    Decimal Literal Syntax
    

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21. @jwo
    3.times{puts'blah'.object_id}!
    # => 70287241728160!
    # => 70287241728080!
    # => 70287241728020!
    !
    3.times{puts'blah'f.object_id}!
    # => 70287241709760 !
    # => 70287241709760!
    # => 70287241709760
    Frozen String Literal
    (Same)
    

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22. @jwo
    $ stackprof data/stackprof-cpu-4120-1384979644.dump --text --limit 4
    ==================================
    Mode: cpu(1000)
    Samples: 9145 (1.25% miss rate)
    GC: 448 (4.90%)
    ==================================
    TOTAL (pct) SAMPLES (pct) FRAME
    236 (2.6%) 231 (2.5%) String#blank?
    546 (6.0%) 216 (2.4%) ActiveRecord::ConnectionAdapters::Mysql2Adapter#select
    212 (2.3%) 199 (2.2%) Mysql2::Client#query_with_timing
    !
    $ stackprof data/stackprof-cpu-4120-1384979644.dump --method 'String#blank?'
    String#blank? (lib/active_support/core_ext/object/blank.rb:80)
    samples: 231 self (2.5%) / 236 total (2.6%)
    callers:
    112 ( 47.5%) Object#present?
    code:
    | 80 | def blank?
    187 (2.0%) / 187 (2.0%) | 81 | self !~ /[^[:space:]]/
    Profiling Tools (rb_profile_frames)
    

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23. @jwo
    Install today!
    

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