;;;;3.12 Input/Output
;Adam Nelson
;Chet Tobrey


(egs :3.12
     #| in order for the next two examples to work properly "test.txt" must not exist in the directory|#
     (eg '(with-open-file(stream "test.txt" :direction :output)
           (print '(hello there) stream)
           (princ 'goodbye stream))
         :of "using the macro with-open-stream to open a file and associate it with a stream"
         )
     (eg '(with-open-file (stream "test.txt" :direction :input)
           (list (read stream)(read-char stream)(read stream)
            (read stream nil 'eof)))
         :of "using the macro with-open file to open test.txt and associate it with a stream"
         )
     (eg '(delete-file "test.txt")
         :of "deleting the file so this example can run again and again")
     (eg '(format t "hello, world")
         :of " the first argument of the function format is the stream to print to. here we use t to specify the terminal"
         )
     (eg '(format t "~&~a plus ~s is ~f" "two" "two" 4)
         :of "the format directive ~&~ moves to a fresh line. ~a prints the next argument as princ would")
     (eg '(let ((numbers '(1 2 3 4 5)))
           (format t "~&~{~r~^ plus ~} is ~@r"
            numbers (apply #'+ numbers)))
         :of "~r prints the next argument which should be a number and ~~@r prints a number as a roman numeral."))