Optionally have ldpath return RDF::Literals instead of Strings #16
Description
Description
An ldpath program can request a result in a specific language, but if language is not specified, all literals will be returned for all languages. Since the results are returned as strings, the language tagging is lost. This prevents the caller from processing the results based on language.
This can be ameliorated by allowing the #evaluate method to have an optional parameter requesting that results be returned as RDF::Literals instead of Strings.
Rationale
Callers of ldpath may want to get all possible values for all languages and have language specific processing in the calling app.
Use Case
Ldpath is used to get values for two related properties. Each property's values are sorted by language making the two sets of property results align by language.
The values can be requested by language, but that assumes you know in advance all the possible languages.
NOTE: This sorting is happening in the calling app. Without language tagging, this type of sorting cannot be done.
Desired Ordering
term = ["dried milk", "getrocknete Milch", "lait en poudre"]
desc = ["powdery", "Pulverförmig", "poudreux"]
Undesired Ordering
term = ["dried milk", "getrocknete Milch", "lait en poudre"]
desc = ["poudreux", "powdery", "Pulverförmig"]
Expected Results
results = ldpath_program.evaluate(subject_uri, context: graph, limit_to_context: true, literal_results: true)
results # [RDF::Literal<"milk"@en>, RDF::Literal<"milche"@de>, RDF::Literal<"lait"@fr>]
Actual Results
literal_results is not a parameter in the current implementation
results = ldpath_program.evaluate(subject_uri, context: graph, limit_to_context: true)
results # ["milk", "milche", "lait"]