This is written for Guile and works (it seems) on version 1.6.7. I'd like to know how it can be rewritten to get rid of the calls to primitive-eval, which, according to the documentation, evaluates the expression in the top-level environment specified by the current module.

 (define (load-all-modified . files) 
   ; Load each of the given files if it's been modified since it was last loaded. 
   (map (lambda (f) (load-if-modified f)) files)) 
 (define (load-if-modified fname) 
   ; Load the contents of the file with the given name if the file hasn't been 
   ; loaded before or if the file has been modified after being loaded; otherwise 
   ; do nothing. 
   (let ((fp (%search-load-path fname))) 
      (if (not fp) 
         (error (string-append "Can't find the file " fname 
                               " in %load-path, or it's unreadable.")) 
            ((sym (string->symbol (string-append fname ":mtime"))) 
             (mtime (stat:mtime (stat fp)))) 
            (if (and (defined? sym) (apply <= (list mtime (primitive-eval sym)))) 
               (display (string-append fname " unmodified, nothing done.")) 
                  (primitive-eval (list 'define sym mtime)) 
                  (load-from-path fname) 
                  (display (string-append "Modified file " fname " loaded."))))