problem translating functions?

[andimou]

For the following YARRRML document:

prefixes:
 ex: "http://www.semanticweb.org/tijnd/"
 ontology: "http://www.semanticweb.org/tijnd/ontology/"
 schema: "https://schema.org/"
 idlab-fn: "http://example.com/idlab/function/"
 grel: "http://users.ugent.be/~bjdmeest/function/grel.ttl#"
 owl: "http://www.w3.org/2002/07/owl#"
 rdf: "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
 rdfs: "http://www.w3.org/2000/01/rdf-schema#"
 xsd: "http://www.w3.org/2001/XMLSchema#"
sources:
  imdb:
   access: imdb_video_game_rating_modified.csv
   referenceFormulation: csv

mappings:
  director:
    sources:
      - imdb
    s: ex:Person/$(title) #Not really the correct subject, only used to simply test it
    po:
      - [a, schema:Person]
      - p: schema:name
        o:  
            function: grel:string_split
            parameters:
              - [grel:p_string_sep, ", "]
              - [grel:valueParameter, $(directors)]

Yatter has problems using the function, mainly with the ", " it gives an error "objectlist expected."

The same YARRRML document is properly translated with Matey.

The dataset considered for this task is this: https://www.kaggle.com/datasets/nyagami/video-game-ratings-from-imdb (if it matters)

[dachafra]

This is already solved! Thanks :)