Migrate action and infoset to pure-python cython.

src/pygambit/core/action.pxi

@@ -19,13 +19,11 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #
-import typing
 
-from libcpp.string cimport string
-
-cdef class Action:
+@cython.cclass
+class Action:
     """A choice available at an information set."""
-    cdef c_GameAction action
+    action = cython.declare(c_GameAction)
 
     def __repr__(self):
         return (
@@ -35,21 +33,15 @@ cdef class Action:
             f"in game '{self.infoset.game.title}'>"
         )
 
-    def __richcmp__(self, other, whichop) -> bool:
+    def __eq__(self, other: typing.Any) -> bool:
         if isinstance(other, Action):
-            if whichop == 2:
-                return self.action.deref() == (<Action>other).action.deref()
-            elif whichop == 3:
-                return self.action.deref() != (<Action>other).action.deref()
-            else:
-                raise NotImplementedError
-        else:
-            if whichop == 2:
-                return False
-            elif whichop == 3:
-                return True
-            else:
-                raise NotImplementedError
+            return self.action.deref() == (<Action> other).action.deref()
+        return False
+
+    def __ne__(self, other: typing.Any) -> bool:
+        if isinstance(other, Action):
+            return self.action.deref() != (<Action> other).action.deref()
+        return True
 
     def __hash__(self) -> long:
         return long(<long>self.action.deref())
@@ -103,13 +95,9 @@ cdef class Action:
     def prob(self) -> typing.Union[decimal.Decimal, Rational]:
         """
         Get or set the probability a chance action is played.
-
-        Parameters
-        ----------
-        value : Any
-            The probability the action is played.  This can be any numeric type, or any object that
-            has a string representation which can be interpreted as an integer,
-            decimal, or rational number.
+        When setting the probability, the value can be any numeric type, or any object that
+        has a string representation which can be interpreted as an integer,
+        decimal, or rational number.
 
         Raises
         ------

src/pygambit/core/infoset.pxi

@@ -20,9 +20,14 @@
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #
 
-cdef class Members(Collection):
+
+@cython.cclass
+class Members(Collection):
     """The set of nodes which are members of an information set."""
-    cdef c_GameInfoset infoset
+    infoset = cython.declare(c_GameInfoset)
+
+    def __init__(self, infoset: Infoset):
+        self.infoset = infoset.infoset
 
     def __len__(self):
         return self.infoset.deref().NumMembers()
@@ -36,9 +41,10 @@ cdef class Members(Collection):
         return n
 
 
-cdef class Actions(Collection):
+@cython.cclass
+class Actions(Collection):
     """The set of actions which are available at an information set."""
-    cdef c_GameInfoset infoset
+    infoset = cython.declare(c_GameInfoset)
 
     def add(self, action=None):
         """Add an action at the information set.  If `action` is not null, the new action
@@ -60,36 +66,32 @@ cdef class Actions(Collection):
     def __getitem__(self, act):
         if not isinstance(act, int):
             return Collection.__getitem__(self, act)
-        cdef Action a
+        a = cython.declare(Action)
         a = Action()
         a.action = self.infoset.deref().GetAction(act+1)
         return a
 
-cdef class Infoset:
+
+@cython.cclass
+class Infoset:
     """Represents an information set in a :py:class:`Game`."""
-    cdef c_GameInfoset infoset
+    infoset = cython.declare(c_GameInfoset)
 
     def __repr__(self) -> str:
         return (
             f"<Infoset [{self.infoset.deref().GetNumber()-1}] '{self.label}' "
             f"for player '{self.player.label}' in game '{self.game.title}'>"
          )
-    
-    def __richcmp__(Infoset self, other, whichop) -> bool:
+
+    def __eq__(self, other: typing.Any) -> bool:
         if isinstance(other, Infoset):
-            if whichop == 2:
-                return self.infoset.deref() == (<Infoset>other).infoset.deref()
-            elif whichop == 3:
-                return self.infoset.deref() != (<Infoset>other).infoset.deref()
-            else:
-                raise NotImplementedError
-        else:
-            if whichop == 2:
-                return False
-            elif whichop == 3:
-                return True
-            else:
-                raise NotImplementedError
+            return self.infoset.deref() == (<Infoset> other).infoset.deref()
+        return False
+
+    def __ne__(self, other: typing.Any) -> bool:
+        if isinstance(other, Infoset):
+            return self.infoset.deref() != (<Infoset> other).infoset.deref()
+        return True
 
     def __hash__(self) -> long:
         return long(<long>self.infoset.deref())
@@ -155,18 +157,15 @@ cdef class Infoset:
     @property
     def actions(self) -> Actions:
         """Returns the set of actions at the information set."""
-        cdef Actions a
+        a = cython.declare(Actions)
         a = Actions()
         a.infoset = self.infoset
         return a
 
     @property
     def members(self) -> Members:
         """Returns the set of nodes which are members of the information set."""
-        cdef Members m
-        m = Members()
-        m.infoset = self.infoset
-        return m
+        return Members(self)
 
     @property
     def player(self) -> Player:

src/pygambit/gambit.pyx

@@ -27,6 +27,7 @@ import fractions
 import warnings
 import typing
 
+import cython
 from libcpp cimport bool
 from libcpp.string cimport string
 import typing