X-Git-Url: https://svn.cri.ensmp.fr/git/linpy.git/blobdiff_plain/23787dd83c4990ca14e52ce3ddff256e26397cdc..30df3336bf6b16524326d28c2c15475aa2e5328d:/pypol/linear.py?ds=inline

diff --git a/pypol/linear.py b/pypol/linear.py
index d1aa882..343acc7 100644
--- a/pypol/linear.py
+++ b/pypol/linear.py
@@ -1,7 +1,3 @@
-'''
-VERY MESSY, made notes on where I will change things
-'''
-
 import functools
 import numbers
 import ctypes, ctypes.util
@@ -162,7 +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):
@@ -300,7 +297,7 @@ class Expression:
 
 def constant(numerator=0, denominator=None):
     if denominator is None and isinstance(numerator, numbers.Rational):
-        return Expression(constant=numerator)
+        return Expression(constant=3)
     else:
         return Expression(constant=Fraction(numerator, denominator))
 
@@ -363,11 +360,8 @@ class Polyhedron:
                         raise TypeError('non-integer constraint: '
                                 '{} <= 0'.format(constraint))
                 self._inequalities.append(constraint)      
-        print('in polyhedron')  
-        #print(self.constraints())
         self._bset = self.to_isl()
-        #print(self._bset)
-        return self 
+        return self._bset 
    
   
     @property
@@ -510,31 +504,39 @@ class Polyhedron:
     
     def to_isl(self):
         space = libisl.isl_space_set_alloc(_CONTEXT, 0, len(self.symbol_count()))
-        bset = libisl.isl_basic_set_universe(libisl.isl_space_copy(space))
-        copy = libisl.isl_basic_set_copy(bset)
+        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))
-        for value in self.equalities:    
-            for value in self.equalities:
-                #need method to get expression value 
-                if self._equalities:
-                    value = self._equalities.method_get_value_from_expression()
-                    ceq = libisl.isl_constraint_set_constant_val(ceq, value ) 
-                    #ceq = libisl.isl_constraint_set_coefficient_si(ceq, libisl.isl_set_dim, self.symbols(), value)                              
-        '''
         cin = libisl.isl_inequality_alloc(libisl.isl_local_space_copy(ls))
-        for item in self.inequalities:     
-                   for item in self.inequalities:
-                if isinstance(item, int):
-                    cin = libisl.isl_constraint_set_constant_si(cin, item) 
-                else:    
-                    cin = libisl.isl_constraint_set_coefficient_si(cin, libisl.isl_set_dim, self.symbols(), item)
-                    '''
-        bsetfinal = libisl.isl_basic_set_add_contraint(copy, ceq)
-        #bsetfinal = libisl.isl_basic_set_add_contraint(copy, cin)
-        string = libisl.isl_printer_print_basic_set(bsetfinal)
+        d = Expression().__dict__  #write expression values to dictionary in form {'_constant': value, '_coefficients': value}      
+        '''
+        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:
+            if '_constant' in d:
+                value = d.get('_constant')
+                ceq = libisl.isl_constraint_set_constant_si(ceq, value)
+            if '_coefficients' in d: 
+                value_co = d.get('_coefficients')
+                if value_co:   #if dictionary not empty add coefficient as to constraint    
+                    ceq = libisl.isl_constraint_set_coefficient_si(ceq, libisl.isl_set_dim, self.symbols(), value_co)  
+            bset = libisl.isl_set_add_constraint(bset, ceq) 
+                       
+        if self._inequalities:     
+            if '_constant' in d:
+                value = d.get('_constant')
+                cin = libisl.isl_constraint_set_constant_si(cin, value)   
+            if '_coefficients' in d: 
+                value_co = d.get('_coefficients')   
+                if value_co: #if dictionary not empty add coefficient as to constraint
+                    cin = libisl.isl_constraint_set_coefficient_si(cin, libisl.isl_set_dim, self.symbols(), value_co)
+            bset = libisl.isl_set_add_constraint(bset, cin) 
+        ip = libisl.isl_printer_to_str(_CONTEXT) #create string printer
+        ip = libisl.isl_printer_print_set(ip, bset) #print set to printer 
+        string = libisl.isl_printer_get_str(ip)   #get string from printer
         print(string)
-        return self
+        return bset
 
 empty = eq(1, 1)