It's also worth mentioning that a "lispier" way of doing this is to use parameters, described in "6.11.2 Parameters". I get the impression that you were asking this more for curiosity about how the language implementation works than to solve a problem, but I might be wrong in that assumption and people who are looking to solve this problem might come upon this thread in the future. The example looks like this after re-writing to use parameters (and it displays the correct output on my machine):
-------------testexport.scm begin---------------------------------- (define-module (testexport) #:use-module (ice-9 pretty-print) #:use-module (env) ) (define (main) (pretty-print (string-append "varA in main: " (varA))) (pretty-print (string-append "varB in main: " (varB))) (pretty-print (string-append "varC in main: " (varC))) ) (main) -------------testexport.scm end---------------------------------- -------------env.scm begin---------------------------------- (define-module (env) #:use-module (ice-9 pretty-print) #:export(varA varB varC)) (define varA (make-parameter "A")) (define varB (make-parameter "")) (define varC (make-parameter "")) (define testval "x") (cond ((string= testval "x") (varB "B")) ((string= testval "y") (varB "error")) ((string= testval "z") (varB "null")) ) (pretty-print (string-append "varB post cond: " (varB))) (when (string= testval "x") (varC "C")) (pretty-print (string-append "varC post if: " (varC))) -------------env.scm end----------------------------------
