Skip recursive map_object for scalars with no range

[matentzn]

Fixes #172

When a slot has range=None and no any_of enums, _map_value_by_range now returns scalar values directly instead of recursing into map_object with None as the source type. This eliminates spurious "Unexpected: ... for type None" warnings.

[Copilot]

Pull request overview

Adjusts ObjectTransformer._map_value_by_range to avoid pointless recursion when the source slot has no declared range, reducing noisy “Unexpected …” warnings during normal transforms (Fixes #172).

Changes:

• Add a fast-path return for scalar values when source_class_slot.range is None/"Any" and there are no any_of enums.
• Prevents map_object(..., source_type=None, ...) being called for scalar values in that case.

Comments suppressed due to low confidence (1)

src/linkml_map/transformer/object_transformer.py:606

• The new early-return only skips recursion when v itself is a scalar. For multivalued slots with range None/"Any" (e.g., v is a list of strings/ints), this still recurses into map_object for each element and will continue emitting the same spurious "Unexpected" warnings. Consider extending the guard to also return the collection unchanged when v is a list/dict whose elements/values are all scalars (i.e., nothing nested to recurse into).

            # No range and no any_of enums: nothing to recurse into for scalars
            if not isinstance(v, (dict, list)):
                return v

        if source_class_slot.multivalued:
            if isinstance(v, list):
                return [self.map_object(v1, source_class_slot_range, target_range) for v1 in v]
            elif isinstance(v, dict):

[matentzn]

@amc-corey-cox this works for me but I am not 100% certain of the side effects. As far as I can see, the only consequence is avoiding an unnecessary warning to be printed.

[amc-corey-cox]

This looks good to me. Nice work! Thanks @matentzn