Improve tests and docs in STDLIB.

lib/file.ex

@@ -16,7 +16,7 @@ object File
     end
 
     def join(list)
-      Erlang.filename.join list.map(_.to_bin)
+      String.new Erlang.filename.join list.map(_.to_bin)
     end
 
     def join(a, b)

lib/list.ex

@@ -37,10 +37,26 @@ object List
     Erlang.lists.keyfind(key, n + 1, self)
   end
 
+  % "Zips" two lists of equal length into one list of two-tuples, where the
+  % first element of each tuple is taken from the first list and the second
+  % element is taken from corresponding element in the second list.
+  %
+  % Raises an error is list sizes does not match.
+  %
+  % ## Examples
+  %
+  %     ['foo, 'bar].zip [1,2]  % => [{'foo,1}, {'bar,2}]
+  %
   def zip(list)
     Erlang.lists.zip(self, list)
   end
 
+  % Does the opposite of `zip`.
+  %
+  % ## Examples
+  %
+  %     {['foo, 'bar], [1,2]} = [{'foo, 1}, {'bar, 2}].unzip
+  %
   def unzip
     Erlang.lists.unzip(self)
   end

lib/ordered_dict.ex

@@ -4,6 +4,12 @@ object OrderedDict
   % Implement OrderedDict as a record. This is done mainly
   % to have improved performance for the equality operator.
   module Mixin
+    % Generates a new OrderedDict from a list of tuples
+    %
+    % ## Examples
+    %
+    %     { 'a: 1, 'b: 2 } = OrderedDict.from_list(['a/1, 'b/2])
+    %
     def from_list(list)
       { 'elixir_orddict__, Erlang.orddict.from_list(list) }
     end

test/elixir/file_test.ex

@@ -18,5 +18,16 @@ object FileTest
     full = File.expand_path("foo/bar")
     full = File.expand_path("bar/../bar", "foo")
   end
+
+  def join_test
+    "foo/bar" = File.join("foo", "bar")
+    "foo/bar/baz" = File.join(["foo", "bar", "baz"])
+  end
+
+  def split_test
+    ["foo"] = File.split("foo")
+    ["foo", "bar"] = File.split("foo/bar")
+    ["foo", "bar", "baz"] = File.split("foo/bar/baz")
+  end
 end
 

test/elixir/list_test.ex

@@ -87,6 +87,23 @@ object ListTest
     true  = [2,4,6].all? -> (i) i rem 2 == 0
   end
 
+  def keyfind_test
+    {'foo, 1} = ['foo/1, 'bar/2].keyfind('foo, 0)
+    {'bar, 2} = ['foo/1, 'bar/2].keyfind('bar, 0)
+    false = ['foo/1, 'bar/2].keyfind('foo, 1)
+    false = ['foo/1, 'bar/2].keyfind('baz, 0)
+  end
+
+  def zip_test
+    [{'foo, 1}, {'bar, 2}] = ['foo, 'bar].zip([1, 2])
+    self.assert_error 'function_clause, -> ['foo].zip([1, 2])
+  end
+
+  def unzip_test
+    {['foo, 'bar], [1,2]} = [{'foo, 1}, {'bar, 2}].unzip
+    self.assert_error 'function_clause, -> [{'foo, 0}, 'bar].unzip
+  end
+
   def head_test
     1  = [1,2,3].head
     1  = [1].head

test/elixir/ordered_dict_test.ex

@@ -12,6 +12,10 @@ object OrderedDictTest
     { 1: 11, 2: 44 } == a_dict.map -> (key, value) key * value
   end
 
+  def from_list_test
+    { 'a: 1, 'b: 2 } = OrderedDict.from_list(['a/1, 'b/2])
+  end
+
   def match_test
     { 1: 2, 2: 4 } = { 2: 4, 1: 2 }