On Fri, Aug 10, 2012 at 1:38 PM, Ray Racine <[email protected]> wrote: > Here https://gist.github.com/3315984 > > The first (test1) works fine. Note it uses a KW arg. > > However, (test2) fails. I thought it was the complexity of the first arg > that I was getting wrong. But when the KW #:label is commented out it works > fine.
What's happening here is that vectors don't subtype the way lists do, so (Vector Symbol Flonum) isn't an appropriate value when you need a (Vector Any (U Real False Interval)). This isn't a problem when you don't have the keyword argument, because Typed Racket can figure out the needed types from the type of `discrete-histogram`, and so gives the vector literals appropriate types. However, TR doesn't currently manage to propagate this information when looking at keyworded applications, which are much more complex when expanded. Thus the behavior you're seeing. If we give TR a little help here, then this works: (define: lst : (Listof (Vector Any (U Real False Interval))) (list #(A 1.0) #(B 2.0) #(B 3.0) (vector 'C (ivl 0.5 1.5)))) (define (test2) (plot (discrete-histogram lst #:label "Hello"))) One way that `plot` could make this easier would be to support lists in addition to vectors for histogram data. -- sam th [email protected] ____________________ Racket Users list: http://lists.racket-lang.org/users
