[Chicken-users] Confused by modules

[Mark Carter]

Chicken scheme has modules, extensions, units, eggs, etc., and I'm 
confused as to how it all works.


I have written a module mcutils.scm, containing:


(module
 mcutils
 (export define-syntax-rule displayln
     file->lines hello-utils until)
 (import chicken extras scheme)

...

;;; a proc calling read-line

...

)

The calling program, vas-parser.scm, contains the lines:

(include "mcutils.scm")
(use mcutils)

When I execute

csi vas-parser.scm

it all works fine.

I can compile successfully using

csc vas-parser.scm

but when I try to run vas-parser, it says that there is an unbound 
variable read-line; which is in unit extras, I believe.

I think that's because the interpreter loads the extras unit 
automatically, but the compiler doesn't??

But my module says to import extras, so why doesn't it work?

I must admit, I'm a bit baffled about what distinguishes 
include/import/use/require-extension and when to use what under which 
circumstances.