* Added (null-environment 5) procedure.

src/ikarus.syntax.ss

@@ -10,7 +10,8 @@
           eval generate-temporaries free-identifier=?
           bound-identifier=? syntax-error datum->syntax
           syntax->datum make-variable-transformer
-          eval-r6rs-top-level boot-library-expand eval-top-level)
+          eval-r6rs-top-level boot-library-expand eval-top-level
+          null-environment)
   (import
     (r6rs)
     (except (ikarus library-manager) installed-libraries)
@@ -2379,6 +2380,10 @@
         (make-eval-environment subst imp*))))
   (define environment?
     (lambda (x) (eval-environment? x)))
+  (define (null-environment n)
+    (unless (eqv? n 5) 
+      (error 'null-environment "~s is not 5" n))
+    (environment '(ikarus null-environment-5)))
   (define eval
     (lambda (x env)
       (unless (eval-environment? env)

src/makefile.ss

@@ -589,6 +589,7 @@
     [new-cafe                i]
     [eval                    i ev]
     [environment             i ev]
+    [null-environment        i]
     [environment?            i]
     [time-it                 i]
     [command-line-arguments  i]

src/todo-r6rs.ss

@@ -535,7 +535,7 @@
     [inexact->exact                             C r5 se]
     [modulo                                     C r5 se]
     [remainder                                  C r5 se]
-    [null-environment                           S r5 se]
+    [null-environment                           C r5 se]
     [quotient                                   C r5 se]
     [scheme-report-environment                  S r5 se]
     ;;;