add single argument integer functions

pystencils/integer_functions.py

@@ -27,6 +27,27 @@ class IntegerFunctionTwoArgsMixIn(sp.Function):
                 raise ValueError("Integer functions can only be constructed with typed expressions")
         return super().__new__(cls, *args)
 
+class IntegerFunctionOneArgMixIn(sp.Function):
+    is_integer = True
+
+    def __new__(cls, arg1):
+        args = []
+
+        if isinstance(arg1, sp.Number) or isinstance(arg1, int):
+            args.append(cast_func(arg1, create_type("int")))
+        elif isinstance(arg1, np.generic):
+            args.append(cast_func(arg1, arg1.dtype))
+        else:
+            args.append(arg1)
+
+
+        try:
+            type = get_type_of_expression(arg1)
+            if not type.is_int():
+                raise ValueError("Argument to integer function is not an int but " + str(type))
+        except NotImplementedError:
+            raise ValueError("Integer functions can only be constructed with typed expressions")
+        return super().__new__(cls, *args)
 
 # noinspection PyPep8Naming
 class bitwise_xor(IntegerFunctionTwoArgsMixIn):
@@ -59,11 +80,11 @@ class int_div(IntegerFunctionTwoArgsMixIn):
 
 
 # noinspection PyPep8Naming
-class int_power_of_2(sp.Function):
+class int_power_of_2(IntegerFunctionOneArgMixIn):
     pass
 
 # noinspection PyPep8Naming
-class post_increment(sp.Function):
+class post_increment(IntegerFunctionOneArgMixIn):
     pass