+1 A flavor of this problem has come up repeatedly, and it will come up again. We need some fix.
On Sep 18, 2012, at 6:28 PM, Ryan Culpepper wrote: > Typed Racket should raise an error saying something like "(Setof Any) cannot > be translated to a contract". Then elaborate in the docs where you discuss > interaction with untyped code about what types cannot be converted to > contracts and maybe why. > > Ryan > > > On 09/18/2012 06:00 PM, Sam Tobin-Hochstadt wrote: >> I'm saying that I don't at the moment know how to avoid giving this >> error, given the current behavior of `set/c`. >> >> On Tue, Sep 18, 2012 at 5:57 PM, Robby Findler >> <[email protected]> wrote: >>> Are you saying it is reasonable that a typed racket program should >>> produce contract constructor errors like that? >>> >>> Robby >>> >>> On Tue, Sep 18, 2012 at 4:53 PM, Sam Tobin-Hochstadt <[email protected]> >>> wrote: >>>> The problem here is that `Any` is a special contract which isn't a >>>> "chaperone contract", and `set/c` requires chaperone contracts. >>>> >>>> It's not obvious to me if this can be detected statically, but you can >>>> work around this by changing `Any` to some other type. >>>> >>>> Sam >>>> >>>> On Tue, Sep 18, 2012 at 5:44 PM, Tony Garnock-Jones <[email protected]> >>>> wrote: >>>>> Hi all, >>>>> >>>>> What could I be doing wrong here? >>>>> >>>>> #lang typed/racket >>>>> (provide (struct-out foo)) >>>>> (struct: foo ([bar : (Setof Any)])) >>>>> >>>>> Racket 5.3.0.24 complains about it ("racket problem.rkt"): >>>>> >>>>> set/c: contract violation >>>>> expected: chaperone-contract? >>>>> given: #<make-contract> >>>>> context...: >>>>> /Users/tonyg/src/racket-typed-matrix/problem.rkt: [running body] >>>>> >>>>> The complaint vanishes if I comment out the provide, remove the bar >>>>> field, or change the bar field's type to Any/Integer/etc. >>>>> >>>>> Tony >>>>> ____________________ >>>>> Racket Users list: >>>>> http://lists.racket-lang.org/users >>>> >>>> >>>> >>>> -- >>>> sam th >>>> [email protected] >>>> ____________________ >>>> Racket Users list: >>>> http://lists.racket-lang.org/users >> >> >> > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
