diff -r 0655411d0f14 json-template.rkt
--- a/json-template.rkt	Thu Aug 11 22:31:46 2011 +0200
+++ b/json-template.rkt	Fri Aug 12 11:22:06 2011 +0200
@@ -13,6 +13,8 @@
 (require/typed "typed-sequence.rkt"
                [sequence->sequence (Sequence -> (Sequenceof Any))])
 
+(define-predicate anyseq? (Sequenceof Any))
+
 (provide: [make-template     (String -> Template)]
           [formatters        (Parameterof (Listof (Pairof String (String -> String))))]
           [meta-left         (Parameterof String)]
@@ -274,8 +276,8 @@
                                 (cons context stack)
                                 default-formatter))
              (let: ([first-iteration? : Boolean #t])
-               (if (sequence? context)
-                   (for ([value (sequence->sequence context)])
+               (if (anyseq? context)
+                   (for ([value (identity #;sequence->sequence context)])
                      (when alternates-with
                        (if first-iteration?
                            (set! first-iteration? #f)