commander-s/scheme/eval-environment.scm

(define (init-evaluation-environment package)
  (let ((structure (reify-structure package)))
    (load-structure structure)
    (rt-structure->environment structure)))

(define *evaluation-environment*)

(define (set-evaluation-package! package-name)
  (set! *evaluation-environment*
        (init-evaluation-environment package-name)))

(define (evaluation-environment)
  *evaluation-environment*)

(define (read-sexp-from-string string)
  (let ((string-port (open-input-string string)))
    (read string-port)))

(define (eval-string str)
  (eval (read-sexp-from-string str)
        (evaluation-environment)))

(define (eval-s-expr s-expr)
  (eval s-expr (evaluation-environment)))