Ruby 2.0 Walkthrough: The Best Bits

509e15b158eaac5ab3a5332a3f89d4a7?s=47 Peter Cooper
February 25, 2013

Ruby 2.0 Walkthrough: The Best Bits

A quick overview of a few of the best bits in Ruby 2.0.

509e15b158eaac5ab3a5332a3f89d4a7?s=128

Peter Cooper

February 25, 2013
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Transcript

  1. 6.

    module FloatDivision refine Fixnum do def /(other); self.to_f / other;

    end end end class MathFun using FloatDivision def self.ratio(a, b) a / b end end p MathFun.ratio(6, 8) THE OLD IDEA (no longer works)
  2. 7.

    module FloatDivision refine Fixnum do def /(other); self.to_f / other;

    end end end class MathFun using FloatDivision def self.ratio(a, b) a / b end end p MathFun.ratio(6, 8)
  3. 8.

    module FloatDivision refine Fixnum do def /(other); self.to_f / other;

    end end end using FloatDivision class MathFun def self.ratio(a, b) a / b end end p MathFun.ratio(6, 8) Main context is OK
  4. 10.

    def some_method(options = {}) defaults = { x: 10, y:

    20, z: 30 } options = defaults.merge(options) p options end some_method x: 1, y: 2
  5. 11.

    def some_method(x: 10, y: 20, z: 30) p x, y,

    z end some_method x: 1, y: 2, z: 3
  6. 17.

    module Bar def my_method "inside the module" end end class

    Foo include Bar def my_method "inside the class" super end end x = Foo.new p x.my_method 1 2
  7. 18.

    module Bar def my_method "inside the module" super end end

    class Foo prepend Bar def my_method "inside the class" end end x = Foo.new p x.my_method 1 2
  8. 19.

    INCLUDE PREPEND Foo class Bar module x object NEITHER Foo

    class x object Object class Object class Foo class Bar module x object Object class
  9. 20.
  10. 24.

    RubyGems 2.0 Lots of refactoring, initial support for stdlib gemification,

    gem search is now remote, arbitrary metadata support & more.
  11. 25.

    RDoc 4.0 Adds Markdown support & ri can now show

    pages (e.g. READMEs with ri rdoc:README)
  12. 26.
  13. 30.

    CSV.load and CSV.dump gone Not considered such a good idea

    in light of the early 2013 YAML vulnerabilities
  14. 31.

    String#chars, #lines, #codepoints, etc. Now return arrays rather than enumerators.

    Use #each_char, #each_line, etc. instead if you need enumerators.
  15. 33.

    tracer = lambda do |event, file, line, id, binding, klass|

    to_display = [event, File.basename(file), line, klass, id] puts "%10s in %s at line %-2d %s:%s" % to_display end set_trace_func tracer # .. normal code here ..
  16. 34.

    tracer = TracePoint.new do |tp| to_display = [tp.event, File.basename(tp.path), tp.lineno,

    tp.defined_class, tp.method_id] puts "%10s in %s at line %-2d %s:%s" % to_display end tracer.enable # .. normal code here ..
  17. 39.

    [1, 4, 9, 13, 14, 22, 40].bsearch { |i| p

    i; i >= 6 } # 13 # 4 # 9 # => 9 (1..1000).bsearch { |i| i > 372 }
  18. 40.

    __dir__ Like __FILE__ but for the current source file’s directory

    Equivalent to File.dirname(File.realpath(__FILE__))
  19. 41.

    to_h and Hash() A new convention. The hash equivalent to

    #to_a A key use is with Struct and OpenStruct
  20. 42.

    User = Struct.new(:name, :age, :status) me = User.new("Peter", 31, :admin)

    me.to_h ENV.to_h Hash(nil) # => {} Hash([]) # => {}