Add unprintable helper functions

3 files changed, 11 insertions, 2 deletions

@@ -15,8 +15,8 @@
                          (sxml->html ,(list 'quasiquote (read port))))))
           (render-specials)))
    (render-unprintables
-    (list (cons "#<unspecified>" (lambda _ '()))
-          (cons "#!eof" (lambda (ch) (list ch #\#))))))
+    (list (cons "#<unspecified>" unprintable/skip)
+          (cons "#!eof" unprintable/backtrack))))
   (else))
 
 (define (main args)
@@ -5,6 +5,9 @@
           render-specials
           render-unprintables
           render-environment
+          ;; Unprintables
+          unprintable/skip
+          unprintable/backtrack
           ;; Re-exports
           environment
           )
@@ -77,3 +77,9 @@
 (define (assq-ref key lis)
   (let ((val (assq key lis)))
     (if val (cdr val) #f)))
+
+(define (unprintable/skip . _)
+  '())
+
+(define (unprintable/backtrack ch)
+  (list ch #\#))