id	summary	reporter	owner	description	type	status	priority	milestone	component	resolution	keywords	cc	planetversion	pltversion
500	"Request for adding parser combinator ""zero"""	anonymous	bzlib	"The library would benefit from having a parser combinator that succeeds if the parser given as a parameter fails. As far as I can tell, the implementation would be:

(define (zero parser)
    (lambda (in) 
        (let-values
            (((v in) ((literal parser) in))) 
            ((if (failed? v) (return '()) fail) in))))"	enhancement	new	major		bzlib/parseq.plt				(1 3)