Readonly operator
operator: "match" | "is" | "=" | "==" | "!=" | "<>" | ">" | ">=" | "<" | "<=" | "in" | "not in" | "is not" | "like" | "not like" | "ilike" | "not ilike" | "@>" | "<@" | "&&" | "?" | "?&" | "!<" | "!>" | "<=>" | "!~" | "~" | "~*" | "!~*" | "@@" | "@@@" | "!!" | "<->" | "regexp" | "+" | "-" | "*" | "/" | "%" | "^" | "&" | "|" | "#" | "<<" | ">>" | "->" | "->>" | "||" | "exists" | "not exists" | "not" | "between" | "between symmetric"