diff --git a/beautiful-racket/br/demo/jsonic/parser.rkt b/beautiful-racket/br/demo/jsonic/parser.rkt
index cda9d00..2315a55 100644
--- a/beautiful-racket/br/demo/jsonic/parser.rkt
+++ b/beautiful-racket/br/demo/jsonic/parser.rkt
@@ -1,4 +1,4 @@
 #lang brag
-jsonic-program: (other-char | s-exp)*
-other-char: CHAR
-s-exp: /OPEN CHAR* /CLOSE
\ No newline at end of file
+jsonic-program: (s-exp | json-char)*
+s-exp: /OPEN CHAR* /CLOSE
+json-char: CHAR
diff --git a/beautiful-racket/br/demo/jsonic/tokenizer.rkt b/beautiful-racket/br/demo/jsonic/tokenizer.rkt
index e36b4b1..4a76b08 100644
--- a/beautiful-racket/br/demo/jsonic/tokenizer.rkt
+++ b/beautiful-racket/br/demo/jsonic/tokenizer.rkt
@@ -5,12 +5,14 @@
     (define our-lexer
       (lexer
        [(eof) eof]
-       ;; (char-complement "\n") means any char but "\n"
-       ;; (complement "\n") means any whole string except "\n"
        [(:seq "//" (:* (char-complement "\n"))) (next-token)]
        ["@$" (token 'OPEN)]
        ["$@" (token 'CLOSE)]
        [any-char (token 'CHAR lexeme)]))
     (our-lexer port))  
   next-token)
-(provide tokenize)
\ No newline at end of file
+(provide tokenize)
+
+
+;; (char-complement "\n") means any char but "\n"
+;; (complement "\n") means any whole string except "\n"
\ No newline at end of file
diff --git a/brag/brag/brag.scrbl b/brag/brag/brag.scrbl
index 5c89749..34ac266 100755
--- a/brag/brag/brag.scrbl
+++ b/brag/brag/brag.scrbl
@@ -858,16 +858,18 @@ If the parse cannot be performed successfully, or if a token in the
 @racket[parse] raises an instance of @racket[exn:fail:parsing].}
 
 
+@defproc[(parse-tree [source any/c #f] 
+                [token-source (or/c (sequenceof token)
+                                    (-> token))])
+         list?]{
+Same as @racket[parse], but the result is converted into a visible parse tree. Useful for testing or debugging a parser.
+}
 
-It's often convenient to extract a parser for other non-terminal rules in the
-grammar, and not just for the first rule. A @tt{brag}-generated module also
-provides a form called @racket[make-rule-parser] to extract a parser for the
-other non-terminals:
 
 @defform[#:id make-rule-parser
          (make-rule-parser name)]{
 Constructs a parser for the @racket[name] of one of the non-terminals
-in the grammar.
+in the grammar. 
 
 For example, given the @tt{brag} program
 @filepath{simple-arithmetic-grammar.rkt}:
@@ -902,8 +904,6 @@ the following interaction shows how to extract a parser for @racket[term]s.
 }
 
 
-Finally, the module provides a set of all the used token types in the grammar
-in @racket[all-token-types]:
 @defthing[all-token-types (setof symbol?)]{
 A set of all the token types used in a grammar.
 
@@ -977,7 +977,14 @@ DrRacket should highlight the offending locations in the source.}
 
 @defmodule[brag/lexer-support]
 
-The @racketmodname[brag/lexer-support] module provides everything from @racketmodname[brag/support], everything from @racketmodname[parser-tools/lex], and everything from @racketmodname[parser-tools/lex-sre], but with a @racket[:] prefix.
+In addition to the exports shown below, the @racketmodname[brag/lexer-support] module also provides everything from @racketmodname[brag/support], and everything from @racketmodname[parser-tools/lex].
+
+@defproc[(apply-tokenizer [tokenizer procedure?] 
+                [source-string (or/c string?
+                                    input-port?)])
+         list?]{
+Repeatedly apply @racket[tokenizer] to @racket[source-string], gathering the resulting tokens into a list. Useful for testing or debugging a tokenizer.
+}
 
 @defform[(:* re ...)]{
 
diff --git a/brag/brag/lexer-support.rkt b/brag/brag/lexer-support.rkt
index eb16303..3ea4fa3 100755
--- a/brag/brag/lexer-support.rkt
+++ b/brag/brag/lexer-support.rkt
@@ -4,4 +4,13 @@
          (prefix-in : parser-tools/lex-sre))
 (provide (all-from-out "support.rkt")
          (all-from-out parser-tools/lex)
-         (all-from-out parser-tools/lex-sre))
\ No newline at end of file
+         (all-from-out parser-tools/lex-sre)
+         (all-defined-out))
+
+(define (apply-tokenizer tokenize in)
+    (define input-port (if (string? in)
+                           (open-input-string in)
+                           in))
+    (define token-producer (tokenize input-port))
+    (for/list ([token (in-producer token-producer eof)])
+              token))
\ No newline at end of file