creating empty property fails

[jgrewe]

the following code works:

section.create_property("test", None)

this version fails with an assert error which cannot be caught:

section.create_property("test", [])

I guess we should allow this.

[achilleas-k]

On a similar note, the same assertion error is triggered when trying to store an empty nix.Value.

>>> nix.Value()
Value{[Nothing] }
>>> section.create_property("test", nix.Value())
... nix/backend/hdf5/PropertyHDF5.cpp:305: static nix::hdf5::h5x::DataType nix::hdf5::PropertyHDF5::fileTypeForValue(nix::DataType): Assertion `false' failed.

I'd expect since an empty (Nothing) value is supported by nix.Value, that at least that would be supported as a property, even if None were not supported.

[gicmo]

@achilleas-k problem is, what would be the type of the underlying property, i.e. the type of the DataSet in HDF5 holding the property? Catching the error earlier is of course needed.

[achilleas-k]

Right, no null-type in the backend. Understandable. By catching the error earlier, do you mean removing Value{[Nothing] } so that the error is caught on creation of the property value?

[achilleas-k]

Empty properties can be created if a dtype is specified.

E.g.,

sec.create_property("empty", values_or_dtype=nix.DataType.String)

Should we close this?