Merge pull request #220 from eriknw/curry_classmethods

`curry` can work on class methods by using the `__get__` descriptor protocol

toolz/functoolz.py

@@ -223,6 +223,11 @@ def __call__(self, *args, **kwargs):
 
         return curry(self._partial, *args, **kwargs)
 
+    def __get__(self, instance, owner):
+        if instance is None:
+            return self
+        return curry(self, instance)
+
     # pickle protocol because functools.partial objects can't be pickled
     def __getstate__(self):
         # dictoolz.keyfilter, I miss you!

toolz/tests/test_functoolz.py

@@ -4,7 +4,7 @@
 from operator import add, mul, itemgetter
 from toolz.utils import raises
 from functools import partial
-from toolz.compatibility import reduce
+from toolz.compatibility import reduce, PY3
 
 
 def iseven(x):
@@ -313,6 +313,93 @@ def f(x, y=0):
     assert cf(y=1)(y=2)(y=3)(1) == f(1, 3)
 
 
+def test_curry_on_classmethods():
+    class A(object):
+        BASE = 10
+
+        def __init__(self, base):
+            self.BASE = base
+
+        @curry
+        def addmethod(self, x, y):
+            return self.BASE + x + y
+
+        @classmethod
+        @curry
+        def addclass(cls, x, y):
+            return cls.BASE + x + y
+
+        @staticmethod
+        @curry
+        def addstatic(x, y):
+            return x + y
+
+    a = A(100)
+    assert a.addmethod(3, 4) == 107
+    assert a.addmethod(3)(4) == 107
+    assert A.addmethod(a, 3, 4) == 107
+    assert A.addmethod(a)(3)(4) == 107
+
+    assert a.addclass(3, 4) == 17
+    assert a.addclass(3)(4) == 17
+    assert A.addclass(3, 4) == 17
+    assert A.addclass(3)(4) == 17
+
+    assert a.addstatic(3, 4) == 7
+    assert a.addstatic(3)(4) == 7
+    assert A.addstatic(3, 4) == 7
+    assert A.addstatic(3)(4) == 7
+
+    # we want this to be of type curry
+    assert isinstance(a.addmethod, curry)
+    assert isinstance(A.addmethod, curry)
+
+
+def test_memoize_on_classmethods():
+    class A(object):
+        BASE = 10
+        HASH = 10
+
+        def __init__(self, base):
+            self.BASE = base
+
+        @memoize
+        def addmethod(self, x, y):
+            return self.BASE + x + y
+
+        @classmethod
+        @memoize
+        def addclass(cls, x, y):
+            return cls.BASE + x + y
+
+        @staticmethod
+        @memoize
+        def addstatic(x, y):
+            return x + y
+
+        def __hash__(self):
+            return self.HASH
+
+    a = A(100)
+    assert a.addmethod(3, 4) == 107
+    assert A.addmethod(a, 3, 4) == 107
+
+    a.BASE = 200
+    assert a.addmethod(3, 4) == 107
+    a.HASH = 200
+    assert a.addmethod(3, 4) == 207
+
+    assert a.addclass(3, 4) == 17
+    assert A.addclass(3, 4) == 17
+    A.BASE = 20
+    assert A.addclass(3, 4) == 17
+    A.HASH = 20  # hashing of class is handled by metaclass
+    assert A.addclass(3, 4) == 17  # hence, != 27
+
+    assert a.addstatic(3, 4) == 7
+    assert A.addstatic(3, 4) == 7
+
+
 def test__num_required_args():
     assert _num_required_args(map) != 0
     assert _num_required_args(lambda x: x) == 1