I’m trying to make a multiplication function that can take either all numbers
or all numbers and one vector, and have it not matter what order they come in.
To do this, I’m using match with list-no-order:
#lang typed/racket
(require plot/typed/utils)
(define listof-number?
(make-predicate (Listof Number)))
(: my* (case->
(-> One)
(Number Number * -> Number)
((Vectorof Real) Real * -> (Vectorof Real))
(Real (Vectorof Real) Real * -> (Vectorof Real))
(Real Real (Vectorof Real) Real * -> (Vectorof Real))
(Real Real Real (Vectorof Real) Real * -> (Vectorof Real))
(Real Real Real Real (Vectorof Real) Real * -> (Vectorof Real))))
; if I could, I would do this:
; (Real * (Vectorof Real) Real * -> (Vectorof Real))
(define my*
(case-lambda
[() 1]
[args (match args
[(list-no-order (? vector? v) (? real? ns) ...)
(v* v (apply * ns))]
[(? listof-number? ns)
(apply * ns)])]))
It’s giving me these errors:
. Type Checker: Expected One, but got Number in: (apply * ns) ; why is it
expecting One there?
. Type Checker: Expected (Vectorof Real), but got Any in: v ; the type
shouldn’t be Any, it should at least
; be VectorTop, and
with the type annotation
; for my* should
tell it that all of the
; vectors are
(Vectorof Real), right?
. Type Checker: Bad arguments to function in apply: ; shouldn’t it be able to
tell that ns is a
Domains: Number * ; (Listof Number),
especially since
Arguments: (Listof Any) * ; listof-number? was
defined with
in: (apply * ns) ; make-predicate?
. Type Checker: Expected One, but got (Vectorof Real) in: (v* v (apply * ns)) ;
why is it expecting One?
. Type Checker: Expected Number, but got (Vectorof Real) in: (v* v (apply *
ns)) ;why is it expecting Number?
. Type Checker: Expected (Vectorof Real), but got Number in: (apply * ns);whyis
it expecting (Vectorof Real)?
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