I have the following directory structure (minimal demo):

main.scm

(load "regex_utils.scm")
(displayln "test")
...

regex_utils.scm

(load "utils.scm")
... ; load many other lib files

utils.scm

(define (displayln x)
  (newline)
  (display x))

But when running scheme < main.scm it will throw error “;Unbound variable: displayln”. How to make displayln available in regex_utils.scm also available in main.scm?

It seems to be related with environment which is used in MIT 6.5151 code base. But I don’t know how to make 2 files sharing one environment since the-environment can be only called in a top-level environment. (I only read Software Design for Flexibility up to section 2.2, so this paragraph may have some errors.)