Expression.symbol moved to Symbol.name
[linpy.git] / pypol / linear.py
index 2c71c02..621a157 100644 (file)
@@ -1,18 +1,17 @@
-import ctypes, ctypes.util
 import functools
 import numbers
 
 from fractions import Fraction, gcd
 
-from . import isl
-from .isl import libisl
+from pypol import isl
+from pypol.isl import libisl
 
 
 __all__ = [
     'Expression', 'Constant', 'Symbol', 'symbols',
     'eq', 'le', 'lt', 'ge', 'gt',
     'Polyhedron',
-    'empty', 'universe'
+    'Empty', 'Universe'
 ]
 
 
@@ -70,7 +69,7 @@ class Expression:
         self._coefficients = {}
         for symbol, coefficient in coefficients:
             if isinstance(symbol, Symbol):
-                symbol = str(symbol)
+                symbol = symbol.name
             elif not isinstance(symbol, str):
                 raise TypeError('symbols must be strings or Symbol instances')
             if isinstance(coefficient, Constant):
@@ -127,15 +126,11 @@ class Expression:
             yield self.coefficient(symbol)
         yield self.constant
 
-    @property
-    def symbol(self):
-        raise ValueError('not a symbol: {}'.format(self))
-
     def issymbol(self):
         return False
 
     def __bool__(self):
-        True
+        return True
 
     def __pos__(self):
         return self
@@ -331,52 +326,52 @@ class Symbol(Expression):
 
     def __new__(cls, name):
         if isinstance(name, Symbol):
-            name = name.symbol
+            name = name.name
         elif not isinstance(name, str):
             raise TypeError('name must be a string or a Symbol instance')
         self = object().__new__(cls)
         self._coefficients = {name: 1}
         self._constant = 0
         self._symbols = tuple(name)
-        self._symbol = name
+        self._name = name
         self._dimension = 1
         return self
 
     @property
-    def symbol(self):
-        return self._symbol
+    def name(self):
+        return self._name
 
     def issymbol(self):
         return True
 
     def __repr__(self):
-        return '{}({!r})'.format(self.__class__.__name__, self._symbol)
+        return '{}({!r})'.format(self.__class__.__name__, self._name)
 
 def symbols(names):
     if isinstance(names, str):
         names = names.replace(',', ' ').split()
-    return (symbol(name) for name in names)
+    return (Symbol(name) for name in names)
 
 
 @_polymorphic_operator
 def eq(a, b):
-    return a._eq(b)
+    return a.__eq__(b)
 
 @_polymorphic_operator
 def le(a, b):
-    return a <= b
+    return a.__le__(b)
 
 @_polymorphic_operator
 def lt(a, b):
-    return a < b
+    return a.__lt__(b)
 
 @_polymorphic_operator
 def ge(a, b):
-    return a >= b
+    return a.__ge__(b)
 
 @_polymorphic_operator
 def gt(a, b):
-    return a > b
+    return a.__gt__(b)
 
 
 class Polyhedron:
@@ -447,27 +442,42 @@ class Polyhedron:
         raise NotImplementedError
 
     def __eq__(self, other):
-        raise NotImplementedError
+        # works correctly when symbols is not passed
+        # should be equal if values are the same even if symbols are different
+        bset = self._toisl()
+        other = other._toisl()
+        return bool(libisl.isl_basic_set_plain_is_equal(bset, other))
 
     def isempty(self):
         bset = self._toisl()
         return bool(libisl.isl_basic_set_is_empty(bset))
 
     def isuniverse(self):
-        raise NotImplementedError
+        bset = self._toisl()
+        return bool(libisl.isl_basic_set_is_universe(bset))
 
     def isdisjoint(self, other):
         # return true if the polyhedron has no elements in common with other
-        raise NotImplementedError
+        #symbols = self._symbolunion(other)
+        bset = self._toisl()
+        other = other._toisl()
+        return bool(libisl.isl_set_is_disjoint(bset, other))
 
     def issubset(self, other):
-        raise NotImplementedError
+        # check if self(bset) is a subset of other
+        symbols = self._symbolunion(other)
+        bset = self._toisl(symbols)
+        other = other._toisl(symbols)
+        return bool(libisl.isl_set_is_strict_subset(other, bset))
 
     def __le__(self, other):
         return self.issubset(other)
 
     def __lt__(self, other):
-        raise NotImplementedError
+        symbols = self._symbolunion(other)
+        bset = self._toisl(symbols)
+        other = other._toisl(symbols)
+        return bool(libisl.isl_set_is_strict_subset(other, bset))
 
     def issuperset(self, other):
         # test whether every element in other is in the polyhedron
@@ -477,6 +487,10 @@ class Polyhedron:
         return self.issuperset(other)
 
     def __gt__(self, other):
+        symbols = self._symbolunion(other)
+        bset = self._toisl(symbols)
+        other = other._toisl(symbols)
+        bool(libisl.isl_set_is_strict_subset(other, bset))
         raise NotImplementedError
 
     def union(self, *others):
@@ -502,10 +516,14 @@ class Polyhedron:
     def __and__(self, other):
         return self.intersection(other)
 
-    def difference(self, *others):
-        # return a new polyhedron with elements in the polyhedron that are not
-        # in the others
-        raise NotImplementedError
+    def difference(self, other):
+        # return a new polyhedron with elements in the polyhedron that are not in the other
+        symbols = self._symbolunion(other)
+        bset = self._toisl(symbols)
+        other = other._toisl(symbols)
+        difference = libisl.isl_set_subtract(bset, other)
+        return difference
+
 
     def __sub__(self, other):
         return self.difference(other)
@@ -519,10 +537,15 @@ class Polyhedron:
         return '{{{}}}'.format(', '.join(constraints))
 
     def __repr__(self):
-        equalities = list(self.equalities)
-        inequalities = list(self.inequalities)
-        return '{}(equalities={!r}, inequalities={!r})' \
-                ''.format(self.__class__.__name__, equalities, inequalities)
+        if self.isempty():
+            return 'Empty'
+        elif self.isuniverse():
+            return 'Universe'
+        else:
+            equalities = list(self.equalities)
+            inequalities = list(self.inequalities)
+            return '{}(equalities={!r}, inequalities={!r})' \
+                    ''.format(self.__class__.__name__, equalities, inequalities)
 
     def _symbolunion(self, *others):
         symbols = set(self.symbols)
@@ -537,30 +560,32 @@ class Polyhedron:
         space = libisl.isl_space_set_alloc(_main_ctx, 0, num_coefficients)
         bset = libisl.isl_basic_set_universe(libisl.isl_space_copy(space))
         ls = libisl.isl_local_space_from_space(space)
-        ceq = libisl.isl_equality_alloc(libisl.isl_local_space_copy(ls))
-        cin = libisl.isl_inequality_alloc(libisl.isl_local_space_copy(ls))
-        '''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())
-                if eq.constant:
-                    value = eq.constant
-                    ceq = libisl.isl_constraint_set_constant_si(ceq, value)
-                for eq in coeff_eq:
-                    num = coeff_eq.get(eq)
-                    iden = symbols.index(eq)
-                    ceq = libisl.isl_constraint_set_coefficient_si(ceq, libisl.isl_dim_set, iden, num)  #use 3 for type isl_dim_set
+        #if there are equalities/inequalities, take each constant and coefficient and add as a constraint to the basic set
+        for eq in self.equalities:
+            ceq = libisl.isl_equality_alloc(libisl.isl_local_space_copy(ls))
+            coeff_eq = dict(eq.coefficients())
+            if eq.constant:
+                value = str(eq.constant).encode()
+                val = libisl.isl_val_read_from_str(_main_ctx, value)
+                ceq = libisl.isl_constraint_set_constant_val(ceq, val)
+            for eq in coeff_eq:
+                number = str(coeff_eq.get(eq)).encode()
+                num = libisl.isl_val_read_from_str(_main_ctx, number)
+                iden = symbols.index(eq)
+                ceq = libisl.isl_constraint_set_coefficient_val(ceq, libisl.isl_dim_set, iden, num)  #use 3 for type isl_dim_set
             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())
-                if ineq.constant:
-                    value = ineq.constant
-                    cin = libisl.isl_constraint_set_constant_si(cin, value)
-                for ineq in coeff_in:
-                    num = coeff_in.get(ineq)
-                    iden = symbols.index(ineq)
-                    cin = libisl.isl_constraint_set_coefficient_si(cin, libisl.isl_dim_set, iden, num)  #use 3 for type isl_dim_set
+        for ineq in self.inequalities:
+            cin = libisl.isl_inequality_alloc(libisl.isl_local_space_copy(ls))
+            coeff_in = dict(ineq.coefficients())
+            if ineq.constant:
+                value = str(ineq.constant).encode()
+                val = libisl.isl_val_read_from_str(_main_ctx, value)
+                cin = libisl.isl_constraint_set_constant_val(cin, val)
+            for ineq in coeff_in:
+                number = str(coeff_in.get(ineq)).encode()
+                num = libisl.isl_val_read_from_str(_main_ctx, number)
+                iden = symbols.index(ineq)
+                cin = libisl.isl_constraint_set_coefficient_val(cin, libisl.isl_dim_set, iden, num)  #use 3 for type isl_dim_set
             bset = libisl.isl_basic_set_add_constraint(bset, cin)
         bset = isl.BasicSet(bset)
         return bset
@@ -575,24 +600,14 @@ class 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 }' '''
-        #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
-
-empty = None #eq(0,1)
-universe = None #Polyhedron()
+            { [i0, i1] : 2i1 >= -2 - i0 } '''
 
+Empty = eq(0,1)
+Universe = Polyhedron()
 
 if __name__ == '__main__':
-    ex1 = Expression(coefficients={'a': 1, 'x': 2}, constant=2)
-    ex2 = Expression(coefficients={'a': 3  , 'b': 2}, constant=3)
-    p = Polyhedron(inequalities=[ex1, ex2])
-    bs = p._toisl()
-    print(bs)
-    print('empty ?', p.isempty())
-    print('empty ?', eq(0, 1).isempty())
+    ex1 = Expression(coefficients={'a': 6, 'b': 6}, constant= 3) #this is the expression that does not work (even without adding values)
+    ex2 = Expression(coefficients={'x': 4, 'y': 2}, constant= 3)
+    p = Polyhedron(equalities=[ex2])
+    p2 = Polyhedron(equalities=[ex2])
+    print(p._toisl()) # checking is values works for toisl