#lang typed/scheme (lambda () (open-input-file "foo" #:mode 'binary) (open-input-file "foo" #:mode 'text) (open-input-file "foo")) ((inst sort Real Real) (list 1 2 3) >) ((inst sort Real Real) (list 1 2 3) #:key (λ: ([x : Real]) (/ 1 x)) >) ((inst sort Real String) (list 1 2 3) #:key number->string stringstring string)