A string representation of a literal value of some kind
A non-empty LiteralValue if v matches the syntax of a LiteralDateTime LiteralDateTime returns LiteralDateTime: {LiteralDateTime} dateTime=DATE_TIME; terminal DATE_TIME returns DateTimeDataType: 'dateTime=' YEAR_FRAG '-' MONTH_FRAG '-' DAY_FRAG 'T' ( (HOUR_FRAG ':' MINUTE_FRAG ':' SECOND_FRAG) | END_OF_DAY_FRAG ) TIMEZONE_FRAG?; terminal fragment YEAR_FRAG: '-'? ( (DIGIT19 DIGIT DIGIT DIGIT+) | ('0' DIGIT DIGIT DIGIT) ); terminal fragment MONTH_FRAG: ('0' DIGIT19) | ('1' DIGIT02); terminal fragment DAY_FRAG: ('0' DIGIT19) | (('1'|'2') DIGIT) | ('3' ('0'|'1')); terminal fragment HOUR_FRAG: (('0'|'1')DIGIT) | ('2'DIGIT03); terminal fragment MINUTE_FRAG: DIGIT05 DIGIT; terminal fragment SECOND_FRAG: DIGIT05 DIGIT ('.' DIGIT+)?; terminal fragment END_OF_DAY_FRAG: '24:00:00' ('.' DIGIT+)?; terminal fragment TIMEZONE_FRAG: 'Z' | ('+'|'-') (('0' DIGIT | '1' DIGIT03) ':' MINUTE_FRAG | '14:00');