I am trying to import this module from the REPL. I got the error below. Any clues ??? The functions works in the REPL when copied and pasted, however it doesn't work when define in the module.



$ rlwrap -c --remember csi -p '(import sutils)'

Warning: reference to possibly unbound identifier `with-input-from-string' in:
Warning:    str->sexp

Warning: reference to possibly unbound identifier `call-with-output-string' in:
Warning:    sexp->str

Error: during expansion of (import ...) - module unresolved: sutils

	Call history:

	<syntax>	  [sexp->file] (##core#begin (close-output-port out))
	<syntax>	  [sexp->file] (close-output-port out)
	<syntax>	  [sexp->file] (##core#undefined)
	<syntax>	  (define (file->sexp filename) (define in (open-input-file filename)) (define sexp (read in)) (begin ...
	<syntax>	  (##core#set! file->sexp (##core#lambda (filename) (define in (open-input-file filename)) (define sex......
	<syntax>	  (##core#lambda (filename) (define in (open-input-file filename)) (define sexp (read in)) (begin (clo......
	<syntax>	  [file->sexp] (##core#let ((in (##core#undefined)) (sexp (##core#undefined))) (##core#set! in (open-input-file fil......
	<syntax>	  [file->sexp] (##core#begin (##core#set! in (open-input-file filename)) (##core#set! sexp (read in)) (close-input-......
	<syntax>	  [file->sexp] (##core#set! in (open-input-file filename))
	<syntax>	  [file->sexp] (open-input-file filename)
	<syntax>	  [file->sexp] (##core#set! sexp (read in))
	<syntax>	  [file->sexp] (read in)
	<syntax>	  [file->sexp] (##core#begin (close-input-port in) sexp)
	<syntax>	  [file->sexp] (close-input-port in)
	<syntax>	  [file->sexp] (##core#undefined)
	<syntax>	  [file->sexp] (##core#undefined)


;;---------------------------------------------;;

File: sutils.import.scm

(module sutils
        (
         sexp->str
         str->sexp
         sexp->file
         file->sexp
         )
        (import chicken scheme)
        ;; (use srfi-6)
        
(define (sexp->str sexp)
  (call-with-output-string
   (lambda (out)
     (write sexp out))))

(define (str->sexp str)
  (with-input-from-string str
    (lambda () (read))))

(define (sexp->file filename sexp)
  (define out (open-output-file filename))
  (begin
    (write sexp out)
    (close-output-port out)))

(define (file->sexp filename)
  (define in (open-input-file filename))
  (define sexp (read in))
  (begin
    (close-input-port in)
             sexp))

) ;;; End of module sutils
         
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

Thanks to: <vandusen> and <evhan>.

Solution: Add (use port)


(module sutils
        (
         sexp->str
         str->sexp
         sexp->file
         file->sexp
         )
        (import chicken scheme)
        (use ports)
...