fix eval for new macro system

Fix mangled datum<->syntax conversions to be more consistent,
as required by the set-of-scopes expander.

Author: mflatt

r6rs-lib/r6rs/private/parse-ref.rkt

@@ -168,4 +168,4 @@
       orig
       im)]
     [_ (let ([m (parse-import-set orig im stx-err)])
-         (list m `(for-label ,m)))]))
+         (list m #`(for-label #,m)))]))

r6rs-lib/rnrs/eval-6.rkt

@@ -19,31 +19,23 @@
                       (vector->list p)))]
    [else p]))
 
-(define (show v)
-  (printf "~s\n" v)
-  v)
-
 (define (r6rs:eval expr env)
   (eval (datum->syntax #f `(#%expression ,(mpair->pair expr))) env))
 
 (define (environment . specs)
   (let ([reqs
          (map (lambda (spec)
-                (syntax->datum
-                 (datum->syntax
-                  #f
-                  (parse-import
-                   #'here
-                   (mpair->pair spec)
-                   (lambda (msg orig stx)
-                     (error 'environment "~a: ~e" msg spec))))))
+                (parse-import
+                 (datum->syntax #f spec)
+                 (datum->syntax #f (mpair->pair spec))
+                 (lambda (msg orig stx)
+                   (error 'environment "~a: ~e" msg spec))))
               specs)])
     (let ([ns (namespace-anchor->empty-namespace anchor)])
       ;; Make sure all modules are instantiated here:
       (parameterize ([current-namespace ns])
         (namespace-require '(rename scheme/base #%base-require require))
         (namespace-require '(only scheme/base #%expression))
         (eval `(#%base-require r6rs/private/prelims 
-                               . ,(datum->syntax #'here (apply append reqs)))))
+                               . ,(apply append reqs))))
       ns)))
-