I think you want to use `(Listof Any)`. Sam
On Thu, Jan 8, 2015 at 6:18 PM, Daniel Prager <daniel.a.pra...@gmail.com> wrote: > I was surprised that cdr upsets the type-checker? How to fix? > > #lang typed/racket > > (: atom? (-> Any Boolean)) > (define (atom? a) > (or (symbol? a) (boolean? a) (number? a) (string? a))) > > (: lat? (-> (List Any) Boolean)) > (define (lat? l) > (cond > [(null? l) #t] > [(atom? (car l)) (lat? (cdr l))] > [else #f])) > > > Type Checker: Polymorphic function `cdr' could not be applied to arguments: > Types: (Pairof a b) -> (b : ((! False @ (cdr) (0 0)) | (False @ (cdr) (0 > 0))) : (cdr (0 0))) > (Listof a) -> (Listof a) > Arguments: (List Any) > Expected result: (List Any) > in: (cdr l) > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users > ____________________ Racket Users list: http://lists.racket-lang.org/users
