Merge branch 'FieldShapeSymbol-FieldStrideSymbol-strictly-positive' into 'master'

Declare FieldShapeSymbol and FieldStrideSymbol as strictly positive

See merge request pycodegen/pystencils!16

pystencils/data_types.py

@@ -105,8 +105,8 @@ class TypedSymbol(sp.Symbol):
         obj = TypedSymbol.__xnew_cached_(cls, *args, **kwds)
         return obj
 
-    def __new_stage2__(cls, name, dtype):
-        obj = super(TypedSymbol, cls).__xnew__(cls, name)
+    def __new_stage2__(cls, name, dtype, *args, **kwargs):
+        obj = super(TypedSymbol, cls).__xnew__(cls, name, *args, **kwargs)
         try:
             obj._dtype = create_type(dtype)
         except (TypeError, ValueError):
@@ -143,6 +143,13 @@ class TypedSymbol(sp.Symbol):
 
         return super().is_positive
 
+    @property
+    def is_nonnegative(self):
+        if self.is_negative is False:
+            return True
+        else:
+            return super().is_nonnegative
+
     @property
     def is_real(self):
         if hasattr(self.dtype, 'numpy_dtype'):

pystencils/kernelparameters.py

@@ -30,7 +30,7 @@ class FieldStrideSymbol(TypedSymbol):
 
     def __new_stage2__(cls, field_name, coordinate):
         name = "_stride_{name}_{i}".format(name=field_name, i=coordinate)
-        obj = super(FieldStrideSymbol, cls).__xnew__(cls, name, STRIDE_DTYPE)
+        obj = super(FieldStrideSymbol, cls).__xnew__(cls, name, STRIDE_DTYPE, positive=True)
         obj.field_name = field_name
         obj.coordinate = coordinate
         return obj
@@ -55,7 +55,7 @@ class FieldShapeSymbol(TypedSymbol):
     def __new_stage2__(cls, field_names, coordinate):
         names = "_".join([field_name for field_name in field_names])
         name = "_size_{names}_{i}".format(names=names, i=coordinate)
-        obj = super(FieldShapeSymbol, cls).__xnew__(cls, name, SHAPE_DTYPE)
+        obj = super(FieldShapeSymbol, cls).__xnew__(cls, name, SHAPE_DTYPE, positive=True)
         obj.field_names = tuple(field_names)
         obj.coordinate = coordinate
         return obj