Add the keys.typedmethodkey decorator

Closes: #296

Author: kuraga

docs/index.rst

@@ -491,7 +491,7 @@ functions with the :func:`cached` and :func:`cachedmethod` decorators:
 
 .. autofunction:: methodkey
 
-   This function is equivalent to :func:`hashkey`, but ignores its
+   This function is similar to :func:`hashkey`, but ignores its
    first positional argument, i.e. `self` when used with the
    :func:`cachedmethod` decorator.
 
@@ -502,6 +502,12 @@ functions with the :func:`cached` and :func:`cachedmethod` decorators:
    ``typedkey(3)`` and ``typedkey(3.0)`` will return different
    results.
 
+.. autofunction:: typedmethodkey
+
+   This function is similar to :func:`typedkey`, but ignores its
+   first positional argument, i.e. `self` when used with the
+   :func:`cachedmethod` decorator.
+
 These functions can also be helpful when implementing custom key
 functions for handling some non-hashable arguments.  For example,
 calling the following function with a dictionary as its `env` argument

src/cachetools/keys.py

@@ -1,6 +1,6 @@
 """Key functions for memoizing decorators."""
 
-__all__ = ("hashkey", "methodkey", "typedkey")
+__all__ = ("hashkey", "methodkey", "typedkey", "typedmethodkey")
 
 
 class _HashedTuple(tuple):
@@ -55,3 +55,8 @@ def typedkey(*args, **kwargs):
     key += tuple(type(v) for v in args)
     key += tuple(type(v) for _, v in sorted(kwargs.items()))
     return key
+
+
+def typedmethodkey(self, *args, **kwargs):
+    """Return a typed cache key for use with cached methods."""
+    return typedkey(*args, **kwargs)

tests/test_cachedmethod.py

@@ -14,8 +14,8 @@ def get(self, value):
         self.count += 1
         return count
 
-    @cachedmethod(lambda self: self.cache, key=keys.typedkey)
-    def get_typed(self, value):
+    @cachedmethod(lambda self: self.cache, key=keys.typedmethodkey)
+    def get_typedmethod(self, value):
         count = self.count
         self.count += 1
         return count
@@ -67,16 +67,16 @@ def test_dict(self):
         cached.cache.clear()
         self.assertEqual(cached.get(1), 2)
 
-    def test_typed_dict(self):
+    def test_typedmethod_dict(self):
         cached = Cached(LRUCache(maxsize=2))
 
-        self.assertEqual(cached.get_typed(0), 0)
-        self.assertEqual(cached.get_typed(1), 1)
-        self.assertEqual(cached.get_typed(1), 1)
-        self.assertEqual(cached.get_typed(1.0), 2)
-        self.assertEqual(cached.get_typed(1.0), 2)
-        self.assertEqual(cached.get_typed(0.0), 3)
-        self.assertEqual(cached.get_typed(0), 4)
+        self.assertEqual(cached.get_typedmethod(0), 0)
+        self.assertEqual(cached.get_typedmethod(1), 1)
+        self.assertEqual(cached.get_typedmethod(1), 1)
+        self.assertEqual(cached.get_typedmethod(1.0), 2)
+        self.assertEqual(cached.get_typedmethod(1.0), 2)
+        self.assertEqual(cached.get_typedmethod(0.0), 3)
+        self.assertEqual(cached.get_typedmethod(0), 4)
 
     def test_lru(self):
         cached = Cached(LRUCache(maxsize=2))
@@ -90,16 +90,16 @@ def test_lru(self):
         cached.cache.clear()
         self.assertEqual(cached.get(1), 2)
 
-    def test_typed_lru(self):
+    def test_typedmethod_lru(self):
         cached = Cached(LRUCache(maxsize=2))
 
-        self.assertEqual(cached.get_typed(0), 0)
-        self.assertEqual(cached.get_typed(1), 1)
-        self.assertEqual(cached.get_typed(1), 1)
-        self.assertEqual(cached.get_typed(1.0), 2)
-        self.assertEqual(cached.get_typed(1.0), 2)
-        self.assertEqual(cached.get_typed(0.0), 3)
-        self.assertEqual(cached.get_typed(0), 4)
+        self.assertEqual(cached.get_typedmethod(0), 0)
+        self.assertEqual(cached.get_typedmethod(1), 1)
+        self.assertEqual(cached.get_typedmethod(1), 1)
+        self.assertEqual(cached.get_typedmethod(1.0), 2)
+        self.assertEqual(cached.get_typedmethod(1.0), 2)
+        self.assertEqual(cached.get_typedmethod(0.0), 3)
+        self.assertEqual(cached.get_typedmethod(0), 4)
 
     def test_nospace(self):
         cached = Cached(LRUCache(maxsize=0))
@@ -141,10 +141,10 @@ def __add__(self, other):
         self.assertEqual(cached.get(1), 2)
         self.assertEqual(cached.get(1.0), 2)
 
-        ref = cached.get_typed(1)
+        ref = cached.get_typedmethod(1)
         self.assertEqual(ref, 3)
-        self.assertEqual(cached.get_typed(1), 3)
-        self.assertEqual(cached.get_typed(1.0), 4)
+        self.assertEqual(cached.get_typedmethod(1), 3)
+        self.assertEqual(cached.get_typedmethod(1.0), 4)
 
         cached.cache.clear()
         self.assertEqual(cached.get(1), 5)