RDF.Literal.Datatype.do_equal_value_different_datatypes-question-mark

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do_equal_value_different_datatypes?(literal, literal)

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Specs

do_equal_value_different_datatypes?(literal(), literal()) :: boolean() | nil

Callback for datatype specific equal_value?/2 comparisons when the given literals have different datatypes.

This callback is called by auto-generated equal_value?/2 function when the given literals have different datatypes and are not derived from each other.

Should return nil when the given arguments are not comparable as literals of this datatype. This behaviour is particularly important for SPARQL.ex where this function is used for the = operator, where comparisons between incomparable terms are treated as errors and immediately leads to a rejection of a possible match.

See also do_equal_value_same_or_derived_datatypes?/2.