On Sat, Apr 9, 2011 at 5:50 PM, Renzo Orsini <renzo.ors...@gmail.com> wrote: > I was trying Typed Racket for the first time. > > when I do "Check Syntax" on the following function (which in a (untyped) > Racket program works correctly) (I simplified the real function): > > #lang typed/racket > > (: elaborate (String String -> Any)) > (define (elaborate in-path-name out-path-name) > (let ([out-path (string->path out-path-name)]) > (call-with-output-file out-path #:exists 'replace > (lambda(out-file) > (list out-file))))) > > the following error message is shown: "for: expected a sequence for (v r), > got something else: #f"
This seems to be a bug in Typed Racket. > If I omit #:exists 'replace > then the message becomes (notes that in the reference manual it is said that > call-with-output file expects a path as first parameter): > > <unsaved editor>:6:8: Type Checker: Polymorphic function > call-with-output-file could not be applied to arguments: > Argument 1: > Expected: String > Given: Path > Argument 2: > Expected: (Output-Port -> a) > Given: (Any -> (List Any)) > > Result type: a > Expected result: Any > in: (call-with-output-file out-path (lambda (out-file) (list out-file))) You need to annotate your `lambda' with a type for `out-file'. See `lambda:' in the documentation. -- sam th sa...@ccs.neu.edu _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
