Merge pull request #105 from iamvery/atoms-koan

Atoms koan

lib/koans/03_atoms.ex

@@ -0,0 +1,29 @@
+defmodule Atoms do
+  use Koans
+
+  koan "Atoms are sort of like strings" do
+    adam = :human
+    assert adam == ___
+  end
+
+  koan "Strings can be converted to atoms, and vice versa" do
+    assert String.to_atom("atomized") == ___
+    assert Atom.to_string(:stringified) == ___
+  end
+
+  koan "It is surprising to find out that booleans are atoms" do
+    assert is_atom(true) == ___
+    assert is_atom(false) == ___
+    assert :true == ___
+    assert :false == ___
+  end
+
+  koan "Modules are also atoms" do
+    assert is_atom(String) == ___
+  end
+
+  koan "Functions can be called on the atom too" do
+    assert :"Elixir.String" == String
+    assert :"Elixir.String".upcase("hello") == ___
+  end
+end

test/koans/atoms_koans_test.exs

@@ -0,0 +1,16 @@
+defmodule AtomsTests do
+  use ExUnit.Case
+  import TestHarness
+
+  test "Atoms" do
+    answers = [
+      :human,
+      {:multiple, [:atomized, "stringified"]},
+      {:multiple, [true, true, true, false]},
+      true,
+      "HELLO",
+    ]
+
+    test_all(Atoms, answers)
+  end
+end