Tree-less LALR hangs when final `start` returns False about lark HOT 5 CLOSED

action          : variable action_operator value
?attr           : (action | conditional | parent)

// Colon is used as separator within a line. Its not needed as terminator.
attrs           : attr (";" attr)* ";"?

// If colon would be required as terminator, we could write:
//attrs         : (attr + ";")+

conditional     : STRING "?" STRING ":" STRING?

expr            : (macro operator attrs)

line            : (expr comment) | expr | comment
file            : line? (newline line?)*

parent          : STRING
newline         : NEWLINE
variable        : STRING
macro           : STRING
comment         : COMMENT

value           : ESCAPED_STRING | NUMBER | STRING

!operator       : ("+:"|":")
!action_operator: ("-="|"+="|"==="|"=="|"=")

COMMENT         : /#[^\n]*/
STRING          : /[a-zA-Z0-9_.-]{2,}/
NUMBER          : /[0-9.]+/
WS              : /[ \t\f]/+
CR              : /\r/
LF              : /\n/
NEWLINE         : (CR? LF)

%import common.ESCAPED_STRING
%ignore WS