Make.Baseval rel_type : t Rel.Type.trel_type the Rel type for the identifier.
val rel_make : t -> t Rel_query.valuerel_make id injects constants identifiers into queries.
val rel_equal : t Rel_query.value -> t Rel_query.value -> bool Rel_query.valuerel_equal id0 id1 determines equality on identifiers in the query language.
val rel_to_text : t Rel_query.value -> string Rel_query.valuerel_to_text id is id as text. FIXME get rid of that.
val to_string : t -> stringto_string id should be an UTF-8 compatible encoding of id.
val of_string : string -> (t, string) Stdlib.resultof_string s parses an identifier from s.