[racket] Type for transposition idiom

From: Neil Toronto (neil.toronto at gmail.com)
Date: Mon Dec 22 21:38:52 EST 2014

Is it possible to get something like this to typecheck in Typed Racket?

#lang typed/racket

(: transpose-vector-list (All (A ...) (-> (List (Vectorof A) ... A)
                                           (Vectorof (List A ... A)))))
(define (transpose-vector-list xss)
   (apply vector-map list xss))

TBH, I haven't even gotten the non-dots version of this working, but the 
above type is what I really need.

Neil ⊥

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