Functional additions.

mom/functional.py

@@ -217,10 +217,12 @@ def oldest(person1, person2):
 
 Predicates, transforms, and walkers
 -----------------------------------
+.. autofunction:: always
+.. autofunction:: constant
 .. autofunction:: identity
 .. autofunction:: loob
-.. autofunction:: always
 .. autofunction:: never
+.. autofunction:: nothing
 """
 
 # pylint: disable-msg=C0302
@@ -1472,3 +1474,29 @@ def never(_):
       ``False``.
   """
   return False
+
+
+def constant(c):
+  """Returns a predicate function that returns the given constant.
+
+  :param c:
+     The constant that the generated predicate function will return.
+  :returns:
+     A predicate function that returns the specified constant.
+  """
+
+  def _func(*args, **kwargs):
+    return c
+
+  return _func
+
+
+def nothing(*args, **kwargs):
+  """A function that does nothing.
+
+  :param args:
+    Any number of positional arguments.
+  :param kwargs:
+    Any number of keyword arguments.
+  """
+  pass

mom/tests/test_mom_functional.py

@@ -766,6 +766,23 @@ def test_never_true(self):
     self.assertFalse(functional.never(True))
 
 
+class Test_constant(unittest2.TestCase):
+  def test_returns_a_function(self):
+    func = functional.constant(4)
+    self.assertTrue(callable(func))
+    self.assertEqual('_func', func.func_name)
+
+  def test_generate_returns_constant(self):
+    func = functional.constant(4)
+    self.assertEqual(4, func(45))
+
+
+class Test_nothing(unittest2.TestCase):
+  def test_does_nothing(self):
+    self.assertEqual(None, funtional.nothing())
+    self.assertEqual(None, funtional.nothing(34, 21, a="something"))
+
+
 class Test_partition_dict(unittest2.TestCase):
   def test_properly_partitions(self):
     args = dict(

tox.ini

@@ -1,8 +1,8 @@
 [tox]
-envlist = py25,py26,py27,py32,pypy
+envlist = py25,py26,py27,py33,pypy
 
 [pytest]
-# Add -v for verbosity.
+#Add -v for verbosity.
 #addopts = -n4 -v --cov mom --cov-report term-missing # --doctest-modules
 addopts = --cov mom --cov-report term-missing # --doctest-modules
 
@@ -41,18 +41,16 @@ deps=pyasn1 >=0.0.13
      pytest-cov
      sphinx
 
-[testenv:py32]
+[testenv:py33]
 deps=coverage >= 3.5
      unittest2py3k
      PyTest
      pytest-xdist
      pytest-cov
-#     sphinx
 
 [testenv:pypy]
 deps=pyasn1 >=0.0.13
      coverage >= 3.5
-#     PyCrypto ==2.0.1
      unittest2
      PyTest
      pytest-xdist