Whats new in Ruby 2.3

@h6165

Abhishek Yadav

ரூபீ ப்ரோக்ராமர்

Co-organizer: Chennai.rb

Whats new in Ruby 2.3

h = { a: 2,
      b: { x: 20, y: 30 },
      c: { m: { today: :me, tomorrow: :you },
           n:   :hello                     }}

h.dig(:c, :m, :today)  # => :me

h.dig(:a, :m, :today)  # => nil
       

Hash#dig

Whats new in Ruby 2.3

A = Struct.new(:foo)
a = [A.new(20), nil].sample

## earlier

b = a && a.foo

## Now

b = a&.foo

Lonely operator

(safe navigation operator)

Whats new in Ruby 2.3

h = { a: 2,
      b: { x: 20, y: 30 },
      c: { m: { today: :me, tomorrow: :you },
           n: "hello"  }
    }

h.fetch_values(:a, :b)  # => [2, {:x=>20, :y=>30}]

Hash#fetch_values

Whats new in Ruby 2.3

Classy.new
NameError: uninitialized constant Classy
Did you mean?  Class

did_you_mean?

Whats new in Ruby 2.3

list = ['Ruby', 'Elixir', 'Python']

list.grep(/y/)
list.grep_v(/y/)

grep_v

Whats new in Ruby 2.3

h = { a: 2, b: 3, c: 4}

[:b, :c].map(&h)  #=> [2, 3]

Hash#to_proc

Whats new in Ruby 2.3

# frozen_string_literal: true

str = 'hello'
str[0] = 'H'   #=> RuntimeError: can't modify frozen String

frozen_string_literal

Whats new in Ruby 2.3

ISeq serialize objects

• Additions to RubyVM::InstructionSequence:

  • RubyVM::InstructionSequence#to_binary_format

  • RubyVM::InstructionSequence.from_binary_format(data) 

• Goal:  machine dependent binaries:

  • fast bootstrap time for big applications
  • reduce memory consumption with several techniques
• ​Not:
  • packing scripts to one package
  • to hide source code
• Experimental currently. With security risks

Whats new in Ruby 2.3

Refs:

• http://nithinbekal.com/posts/ruby-2-3-features/
• https://www.ruby-lang.org/en/news/2015/12/25/ruby-2-3-0-released/
• https://bugs.ruby-lang.org/issues/11788
• https://docs.google.com/document/d/1D0Eo5N7NE_unIySOKG9lVj_eyXf66BQPM4PKp7NvMyQ/pub

@h6165

Abhishek Yadav

ரூபீ ப்ரோக்ராமர்

Co-organizer: Chennai.rb