End of input ($) rule deemed invalid when Posix captures enabled

[RadhiFadlillah]

I have the following code:

func findDayYearPattern(input []byte) int {
	var count int
	var cursor, marker int
	input = append(input, byte(0)) // add terminating null
	limit := len(input) - 1        // lim points at the terminating null

	// Variable for capturing parentheses (twice the number of groups).
	/*!maxnmatch:re2c*/
	yypmatch := make([]int, YYMAXNMATCH*2)
	var yynmatch int
	_ = yynmatch

	// Autogenerated tag variables used by the lexer to track tag values.
	/*!stags:re2c format = 'var @@ int; _ = @@\n'; */

	for { /*!re2c
		re2c:posix-captures   = 1;
		re2c:case-insensitive = 1;
		re2c:eof              = 0;
		re2c:yyfill:enable    = 0;

		re2c:define:YYCTYPE     = byte;
		re2c:define:YYPEEK      = "input[cursor]";
		re2c:define:YYSKIP      = "cursor++";
		re2c:define:YYBACKUP    = "marker = cursor";
		re2c:define:YYRESTORE   = "cursor = marker";
		re2c:define:YYLESSTHAN  = "limit <= cursor";
		re2c:define:YYSTAGP     = "@@{tag} = cursor";
		re2c:define:YYSTAGN     = "@@{tag} = -1";
		re2c:define:YYSHIFTSTAG = "@@{tag} += @@{shift}";

		rxDay = ([0-3]?[0-9]);
		rxYear = (199[0-9]|20[0-3][0-9]);

		{rxDay} { count++; continue }
		{rxYear} { count++; continue }

		* { continue }
		$ { return count }
		*/
	}
}

Back in re2go version 3.1 this compiled nicely, but now in version 4.3 it failed with following message:

error: end of input marker $ in the middle of a rule is not supported

You can check it out here in the playground.

[skvadrik]

This was inadvertently broken in 4.3 by the preliminary work on the way to add generalized end-of-input rule (see release notes for 4.3 for more details.

4.2 should work fine.

I have a fix for this in dev branch, but I didn't realize that old code was broken by the changes in 4.3.

[skvadrik]

I have pushed a fix dcf934f and released version 4.3.1 with it.