Task for defining various definitions.
Task defining a list of global variables in the database. Possibly used in other tasks.
Any valid python expression can be evaluated; any valid key entry of the database will be replaced by it’s value.
Class attribute marking this task as being logical, used in filtering.
A value which allows objects of a given type or types.
Values will be tested using the PyObject_TypeCheck C API call. This call is equivalent to type(obj) in cls.mro(). It is less flexible but faster than Instance. Use Instance when allowing heterogenous values and Typed when the value type is explicit.
The value of a Typed may be set to None
Do nothing (Declared only to avoid raising a NotImplementedError)
In the check() method we write all values to the database.