Add type hints to astep methods

Author: brandonwillard

pymc3/step_methods/arraystep.py

@@ -164,7 +164,7 @@ def step(self, point: Dict[str, np.ndarray]):
 
         return point_new
 
-    def astep(self, apoint, point):
+    def astep(self, apoint: RaveledVars, point: Dict[str, np.ndarray]):
         raise NotImplementedError()
 
 
@@ -225,7 +225,7 @@ def step(self, point):
 
         return new_point
 
-    def astep(self, apoint):
+    def astep(self, apoint: RaveledVars):
         raise NotImplementedError()
 
 

pymc3/step_methods/metropolis.py

@@ -197,7 +197,7 @@ def reset_tuning(self):
             setattr(self, attr, initial_value)
         return
 
-    def astep(self, q0):
+    def astep(self, q0: RaveledVars):
         if not self.steps_until_tune and self.tune:
             # Tune scaling parameter
             self.scaling = tune(self.scaling, self.accepted / float(self.tune_interval))