[plt-dev] reader

Save the program below and run. See surprising error message. Change  
language to #lang scheme and see same surprising error message. Why?


;; The first three lines of this file were inserted by DrScheme. They  
record metadata
;; about the language level of this file in a form that our tools can  
easily process.
#reader(lib "htdp-advanced-reader.ss" "lang")((modname foo) (read-case- 
sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor  
repeating-decimal #t #t none #f ())))

(with-input-from-file "foo.ss" read)