EPAL, the language of even palindromes, is defined as the language generated by the following unambiguous context-free grammar:
$S \rightarrow a a$
$S \rightarrow b b$
$S \rightarrow a S a$
$S \rightarrow b S b$
EPAL is the 'bane' of many parsing algorithms: I have yet to encounter any parsing algorithm for unambiguous CFGs that can parse any grammar describing the language. It is often used to show that there are unambiguous CFGs that cannot be parsed by a particular parser. This inspired my question:
Is there some parsing algorithm accepting only unambiguous CFGs that works on EPAL?
Of course, one can design an ad-hoc two-pass parser for the grammar that parses the language in linear time. I'm interested in parsing methods that have not been designed specifically with EPAL in mind.