Minor improvements to Polyhedra._fromislbasicset(), _toislbasicset()

diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py
index d181646..44826c1 100644 (file)
--- a/pypol/polyhedra.py
+++ b/pypol/polyhedra.py
@@ -95,8 +95,8 @@ class Polyhedron(Domain):
             constant = libisl.isl_constraint_get_constant_val(islconstraint)
             constant = islhelper.isl_val_to_int(constant)
             coefficients = {}
-            for dim, symbol in enumerate(symbols):
-                coefficient = libisl.isl_constraint_get_coefficient_val(islconstraint, libisl.isl_dim_set, dim)
+            for index, symbol in enumerate(symbols):
+                coefficient = libisl.isl_constraint_get_coefficient_val(islconstraint, libisl.isl_dim_set, index)
                 coefficient = islhelper.isl_val_to_int(coefficient)
                 if coefficient != 0:
                     coefficients[symbol] = coefficient
@@ -117,34 +117,35 @@ class Polyhedron(Domain):
     @classmethod
     def _toislbasicset(cls, equalities, inequalities, symbols):
         dimension = len(symbols)
+        indices = {symbol: index for index, symbol in enumerate(symbols)}
         islsp = libisl.isl_space_set_alloc(mainctx, 0, dimension)
         islbset = libisl.isl_basic_set_universe(libisl.isl_space_copy(islsp))
         islls = libisl.isl_local_space_from_space(islsp)
         for equality in equalities:
             isleq = libisl.isl_equality_alloc(libisl.isl_local_space_copy(islls))
             for symbol, coefficient in equality.coefficients():
-                val = str(coefficient).encode()
-                val = libisl.isl_val_read_from_str(mainctx, val)
-                sid = symbols.index(symbol)
+                islval = str(coefficient).encode()
+                islval = libisl.isl_val_read_from_str(mainctx, islval)
+                index = indices[symbol]
                 isleq = libisl.isl_constraint_set_coefficient_val(isleq,
-                    libisl.isl_dim_set, sid, val)
+                    libisl.isl_dim_set, index, islval)
             if equality.constant != 0:
-                val = str(equality.constant).encode()
-                val = libisl.isl_val_read_from_str(mainctx, val)
-                isleq = libisl.isl_constraint_set_constant_val(isleq, val)
+                islval = str(equality.constant).encode()
+                islval = libisl.isl_val_read_from_str(mainctx, islval)
+                isleq = libisl.isl_constraint_set_constant_val(isleq, islval)
             islbset = libisl.isl_basic_set_add_constraint(islbset, isleq)
         for inequality in inequalities:
             islin = libisl.isl_inequality_alloc(libisl.isl_local_space_copy(islls))
             for symbol, coefficient in inequality.coefficients():
-                val = str(coefficient).encode()
-                val = libisl.isl_val_read_from_str(mainctx, val)
-                sid = symbols.index(symbol)
+                islval = str(coefficient).encode()
+                islval = libisl.isl_val_read_from_str(mainctx, islval)
+                index = indices[symbol]
                 islin = libisl.isl_constraint_set_coefficient_val(islin,
-                    libisl.isl_dim_set, sid, val)
+                    libisl.isl_dim_set, index, islval)
             if inequality.constant != 0:
-                val = str(inequality.constant).encode()
-                val = libisl.isl_val_read_from_str(mainctx, val)
-                islin = libisl.isl_constraint_set_constant_val(islin, val)
+                islval = str(inequality.constant).encode()
+                islval = libisl.isl_val_read_from_str(mainctx, islval)
+                islin = libisl.isl_constraint_set_constant_val(islin, islval)
             islbset = libisl.isl_basic_set_add_constraint(islbset, islin)
         return islbset