entity_types_map() does not work reliably

[ChristophLeonhardt]

This concerns the version of the package on the entity_types branch. The line

dbpedia/R/entity_types.R

Line 77 in f4dc779

type_list <- unlist(el, recursive = FALSE)

which was used in a similar function earlier causes issues in entity_types_map(). This is already anticipated in the comments surrounding this line. Long story short: Earlier, a list of lists was passed to the function (as an object corresponding to el here). Now, el is already a list itself, so does not need to be unlisted. If unlisted, the names of the resulting character vector probably won't match the mapping_vector. In consequence, all entities in the data.table are assigned to the category defined in the argument other.

To address this, I think it would suffice to omit the line quoted above. And instead of type_list in the following chunk, you would use el directly here:

dbpedia/R/entity_types.R

Lines 81 to 87 in f4dc779

	types_with_class_raw <- lapply(
	seq_along(type_list),
	function(i) {
	list_name <- names(type_list)[[i]]
	list_elements <- type_list[[i]]
	paste0(list_name, ":", list_elements)
	})

Then, the assignment should work as expected.

Two notes here:

• It might be worth considering changing the name of the resulting column in the data.table from "class" to "category" as this wording is indeed unclear.
• A similar issue occurs with the "old" map_type_to_class() function. Here, the issue results in a different outcome, assigning all classes to all entities as currently visible in the README. This can be addressed in a similar fashion, but if the function is replaced by entity_types_map() fixing the former seems more important.