Add example "animals"

README.md

@@ -10,3 +10,49 @@ Haskell type classes in Ruby.
 Examples
 --------
 
+```ruby
+# This comes from Rust traits example
+# http://rustbyexample.com/trait.html
+
+Animal = Typeclass.new a: Object do
+  fn :name, [:a]
+  fn :noise, [:a]
+
+  fn :talk, [:a] do |a|
+    "#{name a} says \"#{noise a}\""
+  end
+end
+
+Dog = Struct.new(:name)
+
+Typeclass.instance Animal, a: Dog do
+  def name(a)
+    a.name
+  end
+
+  def noise(_a)
+    'woof woof!'
+  end
+end
+
+Sheep = Struct.new(:name)
+
+Typeclass.instance Animal, a: Sheep do
+  def name(a)
+    a.name
+  end
+
+  def noise(_a)
+    'baaah'
+  end
+end
+
+include Animal
+
+dog = Dog['Spike']
+sheep = Sheep['Dolly']
+
+puts talk(dog)
+puts talk(sheep)
+
+```

examples/animals.rb

@@ -0,0 +1,43 @@
+# This comes from Rust traits example
+# http://rustbyexample.com/trait.html
+
+Animal = Typeclass.new a: Object do
+  fn :name, [:a]
+  fn :noise, [:a]
+
+  fn :talk, [:a] do |a|
+    "#{name a} says \"#{noise a}\""
+  end
+end
+
+Dog = Struct.new(:name)
+
+Typeclass.instance Animal, a: Dog do
+  def name(a)
+    a.name
+  end
+
+  def noise(_a)
+    'woof woof!'
+  end
+end
+
+Sheep = Struct.new(:name)
+
+Typeclass.instance Animal, a: Sheep do
+  def name(a)
+    a.name
+  end
+
+  def noise(_a)
+    'baaah'
+  end
+end
+
+include Animal
+
+dog = Dog['Spike']
+sheep = Sheep['Dolly']
+
+puts talk(dog)
+puts talk(sheep)