Ruby refinement example

refinement.rb

#!/usr/bin/env ruby

# here's a good blog post on Refinements => https://blog.codeship.com/ruby-refinements/
# here's some Ruby documentation on Refinements => https://ruby-doc.org/core-2.1.1/doc/syntax/refinements_rdoc.html

class Foo < Struct.new(:bar)
end

module FooTools
  refine Foo do
    def baz
      puts "hey look a baz!"
    end
  end
end

class SomeClass
  using FooTools

  def call_baz(foo)
    foo.baz
  end
end

f = Foo.new("bar")

begin
  f.baz
rescue
  puts "no baz :("
end

SomeClass.new.call_baz(f)

begin
  f.baz
rescue
  puts "no baz :("
end

# irb(main):001:0> #!/usr/bin/env ruby
# => nil
# irb(main):002:0> 
# irb(main):003:0> class Foo < Struct.new(:bar)
# irb(main):004:1> end
# => nil
# irb(main):005:0> 
# irb(main):006:0> module FooTools
# irb(main):007:1>   refine Foo do
# irb(main):008:2*     def baz
# irb(main):009:3>       puts "hey look a baz!"
# irb(main):010:3>     end
# irb(main):011:2>   end
# irb(main):012:1> end
# => #<refinement:Foo@FooTools>
# irb(main):013:0> 
# irb(main):014:0> class SomeClass
# irb(main):015:1>   using FooTools
# irb(main):016:1> 
# irb(main):017:1>   def call_baz(foo)
# irb(main):018:2>     foo.baz
# irb(main):019:2>   end
# irb(main):020:1> end
# => :call_baz
# irb(main):021:0> 
# irb(main):022:0> f = Foo.new("bar")
# => #<struct Foo bar="bar">
# irb(main):023:0> 
# irb(main):024:0> begin
# irb(main):025:1>   f.baz
# irb(main):026:1> rescue
# irb(main):027:1>   puts "no baz :("
# irb(main):028:1> end
# no baz :(
# => nil
# irb(main):029:0> 
# irb(main):030:0> SomeClass.new.call_baz(f)
# hey look a baz!
# => nil
# irb(main):031:0> 
# irb(main):032:0> begin
# irb(main):033:1>   f.baz
# irb(main):034:1> rescue
# irb(main):035:1>   puts "no baz :("
# irb(main):036:1> end
# no baz :(
# => nil
# irb(main):037:0>