That is weird. It works in the nightly build without annotating anything
but `sphere3d`, and likely in the next release as well. Keyword
arguments haven't been all that well-supported in the past, so I'd try
making the arguments to sphere3d positional instead.
FWIW, the easiest way to destructure a vector is
(match-define (vector ctr.x ctr.y ctr.z) ctr.posn)
Also FWIW, in Typed Racket, vectors are annoying function arguments
because their types are invariant; i.e. because vectors are mutable, a
(Vectorof Integer) isn't also a (Vectorof Real). To use the `sphere3d`
function, I had to explicitly instantiate the #:posn argument's type:
(plot3d (sphere3d #:posn ((inst vector Real) 0 0 0) #:r 2))
When it was (vector 0 0 0), TR made it a (Vectorof Integer) and raised a
type error.
It would be great if we had types and functions for operating on
immutable vectors. Until then, it's best to use lists or your own
immutable structures.
Neil ⊥
On 04/19/2014 07:05 PM, Alexander D. Knauth wrote:
Here’s the program:
#lang typed/racket
(require plot/typed plot/typed/utils)
(: vector-x ((Vectorof Real) -> Real))
(: vector-y ((Vectorof Real) -> Real))
(: vector-z ((Vectorof Real) -> Real))
(define (vector-x v) (vector-ref v 0))
(define (vector-y v) (vector-ref v 1))
(define (vector-z v) (vector-ref v 2))
(: sphere3d (#:posn (Vectorof Real) #:r Nonnegative-Real [#:color
Plot-Color] -> renderer3d))
(define (sphere3d #:posn #{ctr.posn : (Vectorof Real)} #:r #{r :
Nonnegative-Real} #:color [#{color : Plot-Color} "black"])
(let: ([ctr.x : Real (vector-x ctr.posn)]
[ctr.y : Real (vector-y ctr.posn)]
[ctr.z : Real (vector-z ctr.posn)])
(isosurface3d (λ: ([x : Real] [y : Real] [z : Real])
(let: ([posn : (Vectorof Real) (vector x y z)])
(vmag^2 (v- posn ctr.posn))))
(ann (sqr r) Real)
(ann (- ctr.x r) (U Real False)) (ann (+ ctr.x r) (U
Real False))
(ann (- ctr.y r) (U Real False)) (ann (+ ctr.y r) (U
Real False))
(ann (- ctr.z r) (U Real False)) (ann (+ ctr.z r) (U
Real False))
#:line-style 'transparent
#:color color)))
And it returns these errors:
. Type Checker: Expected (Vectorof Real), but got Plot-Color in: (define
(sphere3d …) …)
. Type Checker: Expected Nonnegative-Real, but got True in: (define
(sphere3d …) …)
. Type Checker: Expected Plot-Color, but got (Vectorof Real) in: (define
(sphere3d …) …)
. Type Checker: Expected (Vectorof Real), but got False in: (define
(sphere3d …) …)
. Type Checker: Expected Nonnegative-Real, but got False in: (define
(sphere3d …) …)
. Type Checker: Expected Plot-Color, but got (Vectorof Real) in: (define
(sphere3d …) …)
Why am I getting these? Is it somehow mixing up the arguments?
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