Initial commit: new datastructure for iet.

src/sage/dynamics/flat_surfaces/quadratic_strata.py

@@ -67,7 +67,7 @@ def __eq__(self, other):
             sage: QuadraticStratum(4) == QuadraticStratum(0)
             False
         """
-        return isinstance(self, type(other)) and self._zeroes == other._zeroes
+        return type(self) == type(other) and self._zeroes == other._zeroes
 
     def __ne__(self, other):
         r"""
@@ -78,7 +78,7 @@ def __ne__(self, other):
             sage: QuadraticStratum(4) != QuadraticStratum(0)
             True
         """
-        return not isinstance(self, type(other)) or self._zeroes != other._zeroes
+        return type(self) != type(other) or self._zeroes != other._zeroes
 
     def genus(self):
         r"""

src/sage/dynamics/flat_surfaces/strata.py

@@ -799,7 +799,8 @@ def __init__(self, *l, **d):
 
         self._genus = Integer(self._genus)
 
-        zeroes = sorted(filter(lambda x: x > 0, self._zeroes))
+        zeroes = filter(lambda x: x > 0, self._zeroes)
+        zeroes.sort()
 
         if self._genus == 1:
             self._cc = (HypCCA,)
@@ -888,7 +889,7 @@ def __eq__(self, other):
             ...
             TypeError: the right member must be a stratum
         """
-        if not isinstance(self, type(other)):
+        if type(self) != type(other):
             raise TypeError("the right member must be a stratum")
 
         return (self._marked_separatrix == other._marked_separatrix and
@@ -921,7 +922,7 @@ def __ne__(self, other):
             ...
             TypeError: the right member must be a stratum
         """
-        if not isinstance(self, type(other)):
+        if type(self) != type(other):
             raise TypeError("the right member must be a stratum")
 
         return (self._marked_separatrix != other._marked_separatrix or
@@ -945,7 +946,7 @@ def __cmp__(self, other):
             sage: a3_out == a3_in
             False
         """
-        if (not isinstance(self, type(other)) or
+        if (type(self) != type(other) or
             self._marked_separatrix != other._marked_separatrix):
             raise TypeError("the other must be a stratum with same marking")
 
@@ -1412,7 +1413,7 @@ def __cmp__(self, other):
         if not isinstance(other, CCA):
             raise TypeError("other must be a connected component")
 
-        if isinstance(self, type(other)):
+        if type(self) == type(other):
             if self._parent._zeroes > other._parent._zeroes:
                 return 1
             elif self._parent._zeroes < other._parent._zeroes: