Add List koans

lib/koans/lists.ex

@@ -1,7 +1,68 @@
 defmodule Lists do
   use Koans
 
-  koan "We shall contemplate truth by testing reality, via equality" do
+  koan "We can see what is ahead" do
-    assert List.first([1, 2, 3]) == 2
+    assert List.first([1, 2, 3]) == 1
+  end
+
+  koan "Checking what's trailing is also simple" do
+    assert List.last([1, 2, 3]) == 3
+  end
+
+  koan "Diversity is embraced" do
+    assert [1, 2] ++ [:a, "b"] == [1, 2, :a, "b"]
+  end
+
+  koan "Things can evolve" do
+    assert [1, 2, 3] -- [3] == [1, 2]
+  end
+
+  koan "Evolution can have different forms" do
+    assert List.delete([1, 2, 2, 3], 2) == [1, 2, 3]
+  end
+
+  koan "Precision is also valued" do
+    assert List.delete_at([1, 2, 3], 1) == [1, 3]
+  end
+
+  koan "Replication is also possible" do
+    assert List.duplicate("life", 3) == ["life", "life", "life"]
+  end
+
+  koan "Sometimes levelling the playing field is desired" do
+    assert List.flatten([1, [2, 3], 4, [5]]) == [1, 2, 3, 4, 5]
+  end
+
+  koan "Same rules apply to new members that arrive late" do
+    assert List.flatten([1, [2, 3]], [4]) == [1, 2, 3, 4]
+  end
+
+  koan "Order can also be specified for new members" do
+    assert List.insert_at([1, 2, 3], 1, 4) == [1, 4, 2, 3]
+  end
+
+  koan "We can replace things at specified positions" do
+    assert List.replace_at([1, 2, 3], 0, 10) == [10, 2, 3]
+  end
+
+  koan "Replacing something which is not" do
+    assert List.replace_at([1, 2, 3], 10, 0) == [1, 2, 3]
+  end
+
+  koan "Order is bound by nature's laws" do
+    assert List.insert_at([1, 2, 3], 10, 4) == [1, 2, 3, 4]
+    assert List.insert_at([1, 2, 3], -1, 4) == [1, 2, 3, 4]
+  end
+
+  koan "We can also transform ourselves completely" do
+    assert List.to_tuple([1, 2, 3]) == {1, 2, 3}
+  end
+
+  koan "Wrapping other values is a handy option" do
+    assert List.wrap("value") == ["value"]
+  end
+
+  koan "Zipping can be a useful operation" do
+    assert List.zip([[1, 2], [3, 4], [5, 6]]) == [{1, 3, 5}, {2, 4, 6}]
   end
 end

mix.exs

@@ -4,7 +4,7 @@ defmodule Koans.Mixfile do
   def project do
     [app: :elixir_koans,
      version: "0.0.1",
-     elixir: "~> 1.1",
+     elixir: "~> 1.2",
      deps: deps]
   end