Improvements in decorators, data types, caches
authorVivien Maisonneuve <v.maisonneuve@gmail.com>
Wed, 18 Jun 2014 18:50:22 +0000 (20:50 +0200)
committerVivien Maisonneuve <v.maisonneuve@gmail.com>
Wed, 18 Jun 2014 18:50:22 +0000 (20:50 +0200)
pypol/linear.py

index 8e96f35..4f3aeef 100644 (file)
@@ -72,15 +72,17 @@ class Expression:
         if not isinstance(constant, numbers.Rational):
             raise TypeError('constant must be a rational number')
         self._constant = constant
+        self._symbols = tuple(sorted(self._coefficients))
+        self._dimension = len(self._symbols)
         return self
 
-
+    @property
     def symbols(self):
-        yield from sorted(self._coefficients)
+        return self._symbols
 
     @property
     def dimension(self):
-        return len(list(self.symbols()))
+        return self._dimension
 
     def coefficient(self, symbol):
         if isinstance(symbol, Expression) and symbol.issymbol():
@@ -94,9 +96,8 @@ class Expression:
 
     __getitem__ = coefficient
 
-    @property
     def coefficients(self):
-        for symbol in self.symbols():
+        for symbol in self.symbols:
             yield symbol, self.coefficient(symbol)
 
     @property
@@ -107,19 +108,20 @@ class Expression:
         return len(self._coefficients) == 0
 
     def values(self):
-        for symbol in self.symbols():
+        for symbol in self.symbols:
             yield self.coefficient(symbol)
         yield self.constant
 
     def values_int(self):
-        for symbol in self.symbols():
+        for symbol in self.symbols:
             return self.coefficient(symbol)
         return int(self.constant)
 
+    @property
     def symbol(self):
         if not self.issymbol():
             raise ValueError('not a symbol: {}'.format(self))
-        for symbol in self.symbols():
+        for symbol in self.symbols:
             return symbol
 
     def issymbol(self):
@@ -136,7 +138,7 @@ class Expression:
 
     @_polymorphic_method
     def __add__(self, other):
-        coefficients = dict(self.coefficients)
+        coefficients = dict(self.coefficients())
         for symbol, coefficient in other.coefficients:
             if symbol in coefficients:
                 coefficients[symbol] += coefficient
@@ -149,7 +151,7 @@ class Expression:
 
     @_polymorphic_method
     def __sub__(self, other):
-        coefficients = dict(self.coefficients)
+        coefficients = dict(self.coefficients())
         for symbol, coefficient in other.coefficients:
             if symbol in coefficients:
                 coefficients[symbol] -= coefficient
@@ -164,7 +166,7 @@ class Expression:
     @_polymorphic_method
     def __mul__(self, other):
         if other.isconstant():
-            coefficients = dict(self.coefficients)
+            coefficients = dict(self.coefficients())
             for symbol in coefficients:
                 coefficients[symbol] *= other.constant
             constant = self.constant * other.constant
@@ -202,7 +204,6 @@ class Expression:
 
     def __str__(self):
         string = ''
-        symbols = sorted(self.symbols())
         i = 0
         for symbol in symbols:
             coefficient = self[symbol]
@@ -247,7 +248,7 @@ class Expression:
 
     def __repr__(self):
         string = '{}({{'.format(self.__class__.__name__)
-        for i, (symbol, coefficient) in enumerate(self.coefficients):
+        for i, (symbol, coefficient) in enumerate(self.coefficients()):
             if i != 0:
                 string += ', '
             string += '{!r}: {!r}'.format(symbol, coefficient)
@@ -352,6 +353,7 @@ class Polyhedron:
                         raise TypeError('non-integer constraint: '
                                 '{} == 0'.format(constraint))
                 self._equalities.append(constraint)
+        self._equalities = tuple(self._equalities)
         self._inequalities = []
         if inequalities is not None:
             for constraint in inequalities:
@@ -360,15 +362,21 @@ class Polyhedron:
                         raise TypeError('non-integer constraint: '
                                 '{} <= 0'.format(constraint))
                 self._inequalities.append(constraint)
+        self._inequalities = tuple(self._inequalities)
+        self._constraints = self._equalities + self._inequalities
+        self._symbols = set()
+        for constraint in self._constraints:
+            self.symbols.update(constraint.symbols)
+        self._symbols = tuple(sorted(self._symbols))
         return self
 
     @property
     def equalities(self):
-        yield from self._equalities
+        return self._equalities
 
     @property
     def inequalities(self):
-        yield from self._inequalities
+        return self._inequalities
 
     @property
     def constant(self):
@@ -380,26 +388,20 @@ class Polyhedron:
     def isempty(self):
         return bool(libisl.isl_basic_set_is_empty(self._bset))
 
+    @property
     def constraints(self):
-        yield from self.equalities
-        yield from self.inequalities
+        return self._constraints
 
+    @property
     def symbols(self):
-        s = set()
-        for constraint in self.constraints():
-            s.update(constraint.symbols())
-        return sorted(s)
+        return self._symbols
 
     @property
     def dimension(self):
-        return len(self.symbols())
+        return len(self.symbols)
 
     def __bool__(self):
-        # return false if the polyhedron is empty, true otherwise
-        if self._equalities or self._inequalities:
-            return False
-        else:
-            return True
+        return not self.is_empty()
 
     def __contains__(self, value):
         # is the value in the polyhedron?
@@ -408,8 +410,8 @@ class Polyhedron:
     def __eq__(self, other):
         raise NotImplementedError
 
-    def is_empty(self):
-        return
+    def isempty(self):
+        return self == empty
 
     def isuniverse(self):
         return self == universe
@@ -429,11 +431,6 @@ class Polyhedron:
 
     def issuperset(self, other):
         # test whether every element in other is in the polyhedron
-        for value in other:
-            if value == self.constraints():
-                return True
-            else:
-                return False
         raise NotImplementedError
 
     def __ge__(self, other):
@@ -492,14 +489,14 @@ class Polyhedron:
         raise NotImplementedError
 
     def _symbolunion(self, *others):
-        symbols = set(self.symbols())
+        symbols = set(self.symbols)
         for other in others:
-            symbols.update(other.symbols())
+            symbols.update(other.symbols)
         return sorted(symbols)
 
     def _to_isl(self, symbols=None):
         if symbols is None:
-            symbols = self.symbols()
+            symbols = self.symbols
         num_coefficients = len(symbols)
         space = libisl.isl_space_set_alloc(_main_ctx, 0, num_coefficients)
         bset = libisl.isl_basic_set_universe(libisl.isl_space_copy(space))
@@ -509,7 +506,7 @@ class Polyhedron:
         '''if there are equalities/inequalities, take each constant and coefficient and add as a constraint to the basic set'''
         if list(self.equalities): #check if any equalities exist
             for eq in self.equalities:
-                coeff_eq = dict(eq.coefficients)
+                coeff_eq = dict(eq.coefficients())
                 if eq.constant:
                     value = eq.constant
                     ceq = libisl.isl_constraint_set_constant_si(ceq, value)
@@ -520,7 +517,7 @@ class Polyhedron:
             bset = libisl.isl_basic_set_add_constraint(bset, ceq)
         if list(self.inequalities): #check if any inequalities exist
             for ineq in self.inequalities:
-                coeff_in = dict(ineq.coefficients)
+                coeff_in = dict(ineq.coefficients())
                 if ineq.constant:
                     value = ineq.constant
                     cin = libisl.isl_constraint_set_constant_si(cin, value)
@@ -532,23 +529,29 @@ class Polyhedron:
         bset = isl.BasicSet(bset)
         return bset
 
-    def from_isl(self, bset):
+    @classmethod
+    def from_isl(cls, bset):
         '''takes basic set in isl form and puts back into python version of polyhedron
         isl example code gives isl form as:
             "{[i] : exists (a : i = 2a and i >= 10 and i <= 42)}")
             our printer is giving form as:
             b'{ [i0] : 1 = 0 }' '''
+        raise NotImplementedError
+        equalities = ...
+        inequalities = ...
+        return cls(equalities, inequalities)
         #bset = self
-        if self._equalities:
-            constraints = libisl.isl_basic_set_equalities_matrix(bset, 3)
-        elif self._inequalities:
-            constraints = libisl.isl_basic_set_inequalities_matrix(bset, 3)
-        print(constraints)
-        return constraints
+        if self._equalities:
+            constraints = libisl.isl_basic_set_equalities_matrix(bset, 3)
+        elif self._inequalities:
+            constraints = libisl.isl_basic_set_inequalities_matrix(bset, 3)
+        print(constraints)
+        return constraints
 
 empty = None #eq(0,1)
 universe = None #Polyhedron()
 
+
 if __name__ == '__main__':
     ex1 = Expression(coefficients={'a': 1, 'x': 2}, constant=2)
     ex2 = Expression(coefficients={'a': 3  , 'b': 2}, constant=3)