Add support for repr/str to new_sets (#42)

lib/new_sets.bzl

@@ -220,6 +220,17 @@ def _length(s):
   """
   return len(s._values)
 
+def _repr(s):
+  """Returns a string value representing the set.
+
+  Args:
+    s: A set, as returned by `sets.make()`.
+
+  Returns:
+    A string representing the set.
+  """
+  return repr(s._values.keys())
+
 
 sets = struct(
   make = _make,
@@ -235,4 +246,6 @@ sets = struct(
   difference = _difference,
   length = _length,
   remove = _remove,
+  repr = _repr,
+  str = _repr,
 )

tests/new_sets_tests.bzl

@@ -246,6 +246,24 @@ def _remove_test(ctx):
 
 remove_test = unittest.make(_remove_test)
 
+
+def _repr_str_test(ctx):
+  """Unit test for new_sets.repr and new_sets.str."""
+  env = unittest.begin(ctx)
+
+  asserts.equals(env, "[]", new_sets.repr(new_sets.make()))
+  asserts.equals(env, "[1]", new_sets.repr(new_sets.make([1])))
+  asserts.equals(env, "[1, 2]", new_sets.repr(new_sets.make([1, 2])))
+
+  asserts.equals(env, "[]", new_sets.str(new_sets.make()))
+  asserts.equals(env, "[1]", new_sets.str(new_sets.make([1])))
+  asserts.equals(env, "[1, 2]", new_sets.str(new_sets.make([1, 2])))
+
+  unittest.end(env)
+
+repr_str_test = unittest.make(_repr_str_test)
+
+
 def new_sets_test_suite():
   """Creates the test targets and test suite for new_sets.bzl tests."""
   unittest.suite(
@@ -263,4 +281,5 @@ def new_sets_test_suite():
       contains_test,
       length_test,
       remove_test,
+      repr_str_test,
   )