Trac #478, tests for using closures as method decorators.

tests/run/closure_decorators_T478.pyx

+__doc__ = """
+    >>> Num(13).is_prime()
+    args (Num(13),) kwds {}
+    True
+    >>> Num(13).is_prime(True)
+    args (Num(13), True) kwds {}
+    True
+    >>> Num(15).is_prime(print_factors=True)
+    args (Num(15),) kwds {'print_factors': True}
+    3 5
+    False
+"""
+
+def print_args(func):
+    def f(*args, **kwds):
+        print "args", args, "kwds", kwds
+        return func(*args, **kwds)
+    return f
+    
+
+cdef class Num:
+
+    cdef int n
+    
+    def __init__(self, n):
+        self.n = n
+    
+    def __repr__(self):
+        return "Num(%s)" % self.n
+        
+    @print_args
+    def is_prime(self, bint print_factors=False):
+        if self.n == 2:
+            return True
+        elif self.n < 2:
+            return False
+        elif self.n % 2 == 0:
+            if print_factors:
+                print 2, self.n // 2
+        cdef int i = 3
+        while i*i <= self.n:
+            if self.n % i == 0:
+                if print_factors:
+                    print i, self.n // i
+                return False
+            i += 2
+        return True