I suppose I expected it to work the same way define-type does, where later names are fair game to use. I can say:
#lang typed/racket (require/typed "untyped-struct.rkt" [number-me (MyNumbers -> Number)]) (define-type MyNumbers (U String Number)) (number-me 42) But I can't do that with a struct defined later. It was pretty jarring and took some serious thinking to realize that I needed to move a *require* statement to fix my code when it broke because I decided to put a struct type in the require line. So I was wondering if there was a compelling engineering reason for it to be that way; sounds like there's somewhat of a justification. I can't move all of my require/typed declarations to the end of my TR files, either, since the declarations are needed before certain uses of the bindings I bring in. Is there a recommended rule of thumb for where to put require/typed declarations? On Fri, Feb 8, 2013 at 11:38 PM, Eric Dobson <eric.n.dob...@gmail.com> wrote: > Its the same reason that this program gives an error. > > #lang racket > > (define/contract (f x) > (my-struct? . -> . number?) > 1) > > (struct my-struct ()) > > (f (my-struct)) > > Do you expect this to work? > > We could replace uses of my-struct? with (lambda (x) (my-struct? x)) but I > wonder if the optimizer will see through that or not (Given that it actually > is delaying the resolution of the variable). Also that doesn't return true > to struct-predicate-procedure? and something might depend on that for > optimizations. > > > On Fri, Feb 8, 2013 at 8:20 PM, Joe Gibbs Politz <j...@cs.brown.edu> wrote: >> >> When using require/typed with a struct type in the signature, it seems >> to matter if the require comes before or after the struct definition: >> >> typed.rkt >> ========= >> #lang typed/racket >> >> (require/typed "untyped.rkt" >> [number-me (my-struct -> Number)]) >> >> (struct: my-struct ()) >> >> (number-me (my-struct)) >> >> untyped.rkt >> ========= >> #lang racket/base >> >> (provide number-me) >> (define (number-me _) 52) >> >> >> Running typed.rkt yields: >> >> my-struct?: undefined; >> cannot reference an identifier before its definition >> >> But, if I change typed.rkt to >> >> typed2.rkt >> ========= >> #lang typed/racket >> >> (struct: my-struct ()) >> >> (require/typed "untyped.rkt" >> [number-me (my-struct -> Number)]) >> >> (number-me (my-struct)) >> >> >> There's no error and the call succeeds. >> >> Any reason for the ordering dependency? It's quite inconvenient to be >> shuffling require statements around as soon as you want to put a >> struct in their type, so I'm assuming this wasn't intended. >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users > > ____________________ Racket Users list: http://lists.racket-lang.org/users
