2016 Update

Task/Collections/Elixir/collections-4.elixir

@@ -1,7 +1,15 @@
-empty_map = Map.new             #=> %{}
-map = %{:a => 1, 2 => :b}       #=> %{2 => :b, :a => 1}
-map[:a]                         #=> 1
-map[2]                          #=> :b
+empty_map = Map.new           #=> %{}
+kwlist = [x: 1, y: 2]         #   Key Word List
+Map.new(kwlist)               #=> %{x: 1, y: 2}
+Map.new([{1,"A"}, {2,"B"}])   #=> %{1 => "A", 2 => "B"}
+map = %{:a => 1, 2 => :b}     #=> %{2 => :b, :a => 1}
+map[:a]                       #=> 1
+map[2]                        #=> :b
 
 # If you pass duplicate keys when creating a map, the last one wins:
-%{1 => 1, 1 => 2}               #=> %{1 => 2}
+%{1 => 1, 1 => 2}             #=> %{1 => 2}
+
+# When all the keys in a map are atoms, you can use the keyword syntax for convenience:
+map = %{:a => 1, :b => 2}     #=> %{a: 1, b: 2}
+map.a                         #=> 1
+%{map | :a => 2}              #=> %{a: 2, b: 2}     update only

Task/Collections/Elixir/collections-5.elixir

@@ -1,3 +1,10 @@
-map = %{:a => 1, :b => 2}       #=> %{a: 1, b: 2}
-map.a                           #=> 1
-%{map | :a => 2}                #=> %{a: 2, b: 2}
+empty_set = MapSet.new                  #=> #MapSet<[]>
+set1 = MapSet.new(1..4)                 #=> #MapSet<[1, 2, 3, 4]>
+MapSet.size(set1)                       #=> 4
+MapSet.member?(set1,3)                  #=> true
+MapSet.put(set1,9)                      #=> #MapSet<[1, 2, 3, 4, 9]>
+set2 = MapSet.new([6,4,2,0])            #=> #MapSet<[0, 2, 4, 6]>
+MapSet.union(set1,set2)                 #=> #MapSet<[0, 1, 2, 3, 4, 6]>
+MapSet.intersection(set1,set2)          #=> #MapSet<[2, 4]>
+MapSet.difference(set1,set2)            #=> #MapSet<[1, 3]>
+MapSet.subset?(set1,set2)               #=> false

Task/Collections/Elixir/collections-6.elixir

@@ -1,10 +1,9 @@
-empty_set = HashSet.new                 #=> #HashSet<[]>
-set1 = Enum.into(1..4,HashSet.new)      #=> #HashSet<[2, 3, 4, 1]>
-Set.size(set1)                          #=> 4
-Set.member?(set1,3)                     #=> true
-Set.put(set1,9)                         #=> #HashSet<[2, 3, 4, 1, 9]>
-set2 = Enum.into([0,2,4,6],HashSet.new) #=> #HashSet<[0, 2, 6, 4]>
-Set.union(set1,set2)                    #=> #HashSet<[0, 2, 6, 4, 3, 1]>
-Set.intersection(set1,set2)             #=> #HashSet<[2, 4]>
-Set.difference(set1,set2)               #=> #HashSet<[3, 1]>
-Set.subset?(set1,set2)                  #=> false
+defmodule User do
+  defstruct name: "john", age: 27
+end
+john = %User{}                      #=> %User{age: 27, name: "john"}
+john.name                           #=> "john"
+%User{age: age} = john              #   pattern matching
+age                                 #=> 27
+meg = %User{name: "meg"}            #=> %User{age: 27, name: "meg"}
+is_map(meg)                         #=> true