Fix Expression.__rsub__

[linpy.git] / pypol / linear.py

diff --git a/pypol/linear.py b/pypol/linear.py
index a5f55fa..c169049 100644 (file)
--- a/pypol/linear.py
+++ b/pypol/linear.py
@@ -1,9 +1,13 @@
-
 import functools
 import numbers
+import ctypes, ctypes.util
+from pypol import isl
 
 from fractions import Fraction, gcd
 
+libisl = ctypes.CDLL(ctypes.util.find_library('isl'))
+
+libisl.isl_printer_get_str.restype = ctypes.c_char_p
 
 __all__ = [
     'Expression',
@@ -14,6 +18,8 @@ __all__ = [
 ]
 
 
+_CONTEXT = isl.Context()
+
 def _polymorphic_method(func):
     @functools.wraps(func)
     def wrapper(a, b):
@@ -68,6 +74,7 @@ class Expression:
         self._constant = constant
         return self
 
+
     def symbols(self):
         yield from sorted(self._coefficients)
 
@@ -103,6 +110,12 @@ class Expression:
             yield self.coefficient(symbol)
         yield self.constant
 
+    def values_int(self):
+        for symbol in self.symbols():
+            return self.coefficient(symbol)
+        return int(self.constant)
+
+
     def symbol(self):
         if not self.issymbol():
             raise ValueError('not a symbol: {}'.format(self))
@@ -145,7 +158,8 @@ class Expression:
         constant = self.constant - other.constant
         return Expression(coefficients, constant)
 
-    __rsub__ = __sub__
+    def __rsub__(self, other):
+        return -(self - other)
 
     @_polymorphic_method
     def __mul__(self, other):
@@ -177,7 +191,7 @@ class Expression:
         return NotImplemented
 
     def __rtruediv__(self, other):
-        if isinstance(other, Rational):
+        if isinstance(other, self):
             if self.isconstant():
                 constant = Fraction(other, self.constant)
                 return Expression(constant=constant)
@@ -345,9 +359,11 @@ class Polyhedron:
                     if value.denominator != 1:
                         raise TypeError('non-integer constraint: '
                                 '{} <= 0'.format(constraint))
-                self._inequalities.append(constraint)
-        return self
-
+                self._inequalities.append(constraint)      
+        self._bset = self.to_isl()
+        return self._bset 
+   
+  
     @property
     def equalities(self):
         yield from self._equalities
@@ -355,24 +371,46 @@ class Polyhedron:
     @property
     def inequalities(self):
         yield from self._inequalities
+        
+    @property
+    def constant(self):
+        return self._constant
+
+    def isconstant(self):
+        return len(self._coefficients) == 0
+    
+        
+    def isempty(self):
+        return bool(libisl.isl_basic_set_is_empty(self._bset))
 
     def constraints(self):
         yield from self.equalities
         yield from self.inequalities
 
+
     def symbols(self):
         s = set()
         for constraint in self.constraints():
             s.update(constraint.symbols)
-        yield from sorted(s)
-
+            yield from sorted(s)
+            
+    def symbol_count(self):
+        s = []
+        for constraint in self.constraints():
+            s.append(constraint.symbols)
+        return s     
+        
     @property
     def dimension(self):
         return len(self.symbols())
 
     def __bool__(self):
         # return false if the polyhedron is empty, true otherwise
-        raise NotImplementedError
+        if self._equalities or self._inequalities:
+            return False
+        else:
+            return True
+        
 
     def __contains__(self, value):
         # is the value in the polyhedron?
@@ -381,8 +419,8 @@ class Polyhedron:
     def __eq__(self, other):
         raise NotImplementedError
 
-    def isempty(self):
-        return self == empty
+    def is_empty(self):
+        return
 
     def isuniverse(self):
         return self == universe
@@ -402,6 +440,11 @@ 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):
@@ -458,8 +501,56 @@ class Polyhedron:
     @classmethod
     def fromstring(cls, string):
         raise NotImplementedError
+    
+    def printer(self):
+        
+        ip = libisl.isl_printer_to_str(_CONTEXT)
+        ip = libisl.isl_printer_print_val(ip, self) #self should be value
+        string = libisl.isl_printer_get_str(ip).decode()
+        print(string)
+        return string
+    
+    
+    def to_isl(self):
+        space = libisl.isl_space_set_alloc(_CONTEXT, 0, len(self.symbol_count()))
+        bset = libisl.isl_basic_set_empty(libisl.isl_space_copy(space))
+        ls = libisl.isl_local_space_from_space(libisl.isl_space_copy(space))
+        ceq = libisl.isl_equality_alloc(libisl.isl_local_space_copy(ls))
+        cin = libisl.isl_inequality_alloc(libisl.isl_local_space_copy(ls))
+        dict_ex = Expression().__dict__
+        print(dict_ex)
+        '''
+        if there are equalities/inequalities, take each constant and coefficient and add as a constraint to the basic set
+        need to change the symbols method to a lookup table for the integer value for each letter that could be a symbol
+        '''
+        if self.equalities:
+            for _constant in dict_ex:
+                value = dict_ex.get('_constant')
+                ceq = libisl.isl_constraint_set_constant_val(ceq, value)    
+            for _coefficients in dict_ex: 
+                value_co = dict_ex.get('_coefficients')
+                if value_co:       
+                    ceq = libisl.isl_constraint_set_coefficient_si(ceq, libisl.isl_set_dim, self.symbols(), value_co)  
+            bset = libisl.isl_set_add_constraint(bset, ceq)     
+            bset = libisl.isl_basic_set_project_out(bset, libisl.isl_set_dim, 1, 1);                
+        elif self.inequalities:     
+            for _constant in dict_ex:
+                value = dict_ex.get('_constant')
+                cin = libisl.isl_constraint_set_constant_val(cin, value)    
+            for _coefficients in dict_ex: 
+                value_co = dict_ex.get('_coefficients')   
+                if value_co:
+                    cin = libisl.isl_constraint_set_coefficient_si(cin, libisl.isl_set_dim, self.symbols(), value_co)
+            bset = libisl.isl_set_add_contraint(bset, cin) 
+            
+        string = libisl.isl_printer_print_basic_set(bset)
+        print('here')
+        print(bset)
+        print(self)
+        #print(string)
+        return bset
+
+empty = eq(1, 1)
 
 
-empty = le(1, 0)
-
 universe = Polyhedron()