index f8d413e..fe143d4 100644 (file)
@@ -56,14 +56,23 @@ class Polyhedron(Domain):

@property
def equalities(self):
+    """
+    Return a list of the equalities in a set.
+    """
return self._equalities

@property
def inequalities(self):
+    """
+    Return a list of the inequalities in a set.
+    """
return self._inequalities

@property
def constraints(self):
+    """
+    Return ta list of the constraints of a set.
+    """
return self._constraints

@property
@@ -72,13 +81,13 @@ class Polyhedron(Domain):

def disjoint(self):
"""
-        Return this set as disjoint.
+        Return a set as disjoint.
"""
return self

def isuniverse(self):
"""
-        Return true if this set is the Universe set.
+        Return true if a set is the Universe set.
"""
islbset = self._toislbasicset(self.equalities, self.inequalities,
self.symbols)
@@ -88,7 +97,7 @@ class Polyhedron(Domain):

def aspolyhedron(self):
"""
-        Return polyhedral hull of this set.
+        Return polyhedral hull of a set.
"""
return self

@@ -106,18 +115,42 @@ class Polyhedron(Domain):
return True

def subs(self, symbol, expression=None):
+    """
+    Subsitute the given value into an expression and return the resulting expression.
+    """
equalities = [equality.subs(symbol, expression)
for equality in self.equalities]
inequalities = [inequality.subs(symbol, expression)
for inequality in self.inequalities]
return Polyhedron(equalities, inequalities)

+    def _asinequalities(self):
+        inequalities = list(self.equalities)
+        inequalities.extend([-expression for expression in self.equalities])
+        inequalities.extend(self.inequalities)
+        return inequalities
+
+    def widen(self, other):
+        if not isinstance(other, Polyhedron):
+            raise ValueError('argument must be a Polyhedron instance')
+        inequalities1 = self._asinequalities()
+        inequalities2 = other._asinequalities()
+        inequalities = []
+        for inequality1 in inequalities1:
+            if other <= Polyhedron(inequalities=[inequality1]):
+                inequalities.append(inequality1)
+        for inequality2 in inequalities2:
+            for i in range(len(inequalities1)):
+                inequalities3 = inequalities1[:i] + inequalities[i + 1:]
+                inequalities3.append(inequality2)
+                polyhedron3 = Polyhedron(inequalities=inequalities3)
+                if self == polyhedron3:
+                    inequalities.append(inequality2)
+                    break
+        return Polyhedron(inequalities=inequalities)
+
@classmethod
def _fromislbasicset(cls, islbset, symbols):
-        if libisl.isl_basic_set_is_empty(islbset):
-            return Empty
-        if libisl.isl_basic_set_is_universe(islbset):
-            return Universe
islconstraints = islhelper.isl_basic_set_constraints(islbset)
equalities = []
inequalities = []
@@ -198,6 +231,7 @@ class Polyhedron(Domain):
else:
return 'And({})'.format(', '.join(strings))

+
def _repr_latex_(self):
strings = []
for equality in self.equalities:
@@ -208,12 +242,18 @@ class Polyhedron(Domain):

@classmethod
def fromsympy(cls, expr):
+    """
+    Convert a sympy object to an expression.
+    """
domain = Domain.fromsympy(expr)
if not isinstance(domain, Polyhedron):
raise ValueError('non-polyhedral expression: {!r}'.format(expr))
return domain

def tosympy(self):
+    """
+    Return an expression as a sympy object.
+    """
import sympy
constraints = []
for equality in self.equalities:
@@ -222,7 +262,6 @@ class Polyhedron(Domain):
constraints.append(sympy.Ge(inequality.tosympy(), 0))
return sympy.And(*constraints)

-
class EmptyType(Polyhedron):

__slots__ = Polyhedron.__slots__
@@ -236,6 +275,11 @@ class EmptyType(Polyhedron):
self._dimension = 0
return self

+    def widen(self, other):
+        if not isinstance(other, Polyhedron):
+            raise ValueError('argument must be a Polyhedron instance')
+        return other
+
def __repr__(self):
return 'Empty'

@@ -288,41 +332,42 @@ def _polymorphic(func):
@_polymorphic
def Lt(left, right):
"""
-    Return true if the first set is less than the second.
+    Assert first set is less than the second set.
"""
return Polyhedron([], [right - left - 1])

@_polymorphic
def Le(left, right):
"""
-    Return true the first set is less than or equal to the second.
+    Assert first set is less than or equal to the second set.
"""
return Polyhedron([], [right - left])

@_polymorphic
def Eq(left, right):
"""
-    Return true if the sets are equal.
+    Assert first set is equal to the second set.
"""
return Polyhedron([left - right], [])

@_polymorphic
def Ne(left, right):
"""
-    Return true if the sets are NOT equal.
+    Assert first set is not equal to the second set.
"""
return ~Eq(left, right)

@_polymorphic
def Gt(left, right):
"""
-    Return true if the first set is greater than the second set.
+    Assert first set is greater than the second set.
"""
return Polyhedron([], [left - right - 1])

@_polymorphic
def Ge(left, right):
"""
-    Return true if the first set is greater than or equal the second set.
+    Assert first set is greater than or equal to the second set.
"""
return Polyhedron([], [left - right])
+