Squash compiler warnings.

lib/koans/05_functions.ex

@@ -52,7 +52,7 @@ defmodule Functions do
   end
 
   def sum_up(thing) when is_list(thing), do: :entire_list
-  def sum_up(thing), do: :single_thing
+  def sum_up(_thing), do: :single_thing
   koan "You can 'guard' functions against their arguments" do
     assert sum_up([1,2,3]) == :entire_list
     assert sum_up(1) == :single_thing

lib/koans/07_arithmetic.ex

@@ -53,8 +53,9 @@ defmodule Arithmetic do
   end
 
   koan "it can not divide by zero" do
+    div_by = fn(n) -> 1 / n end
     try do
-      1 / 0.0
+      div_by.(0)
     rescue
        ArithmeticError -> true
     end

lib/koans/08_structs.ex

@@ -6,7 +6,8 @@ defmodule Structs do
   end
 
   koan "structs are defined and named after a module" do
-    assert %Person{}
+    person = %Person{}
+    assert person == %Person{}
   end
 
   koan "you can access the fields of a struct" do
@@ -53,7 +54,6 @@ defmodule Structs do
   koan "are basically maps" do
     silvia = %Person{age: 22, name: "Silvia"}
 
-    assert is_map(silvia)
     assert Map.fetch!(silvia, :age) == 22
   end
 end