From 219516b3217bac09238e234de0447559156e6df5 Mon Sep 17 00:00:00 2001
From: Jon Rafkind <rafkind@racket-lang.org>
Date: Thu, 15 Sep 2011 12:50:31 -0600
Subject: [PATCH] [honu] use an empty "begin" if nothing was parsed

---
 .../honu/core/private/honu-typed-scheme.rkt    |  6 +++++-
 collects/honu/core/private/parse2.rkt          | 18 ------------------
 2 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/collects/honu/core/private/honu-typed-scheme.rkt b/collects/honu/core/private/honu-typed-scheme.rkt
index 72ca2a2abd..173ff2515c 100644
--- a/collects/honu/core/private/honu-typed-scheme.rkt
+++ b/collects/honu/core/private/honu-typed-scheme.rkt
@@ -461,7 +461,11 @@ Then, in the pattern above for 'if', 'then' would be bound to the following synt
      (debug "expanded ~a unexpanded ~a\n"
             (if parsed (syntax->datum parsed) parsed)
             (syntax->datum unparsed))
-     (with-syntax ([parsed parsed]
+     ;; if parsed is #f then we don't want to expand to anything that will print
+     ;; so use an empty form, begin, `parsed' could be #f becuase there was no expression
+     ;; in the input such as parsing just ";". hygiene should ensure that this variable
+     ;; will not collide with anything else
+     (with-syntax ([parsed (if (not parsed) #'(begin) parsed)]
                    [(unparsed ...) unparsed])
        (if (null? (syntax->datum #'(unparsed ...)))
          #'parsed
diff --git a/collects/honu/core/private/parse2.rkt b/collects/honu/core/private/parse2.rkt
index bee6c93539..8c19bf65e7 100644
--- a/collects/honu/core/private/parse2.rkt
+++ b/collects/honu/core/private/parse2.rkt
@@ -346,24 +346,6 @@
       (loop (cons parsed all)
             unparsed))))
 
-(define (parse2 forms)
-  (debug "parse forms ~a\n" forms)
-  (when (stx-pair? forms)
-    (define head (stx-car forms))
-    (if (honu-macro? head)
-      (begin
-        (debug "honu macro ~a\n" head)
-        (let-values ([(parsed rest)
-                      ((syntax-local-value head) forms #f)])
-          (with-syntax ([parsed parsed]
-                        [rest rest])
-          #'(splicing-let-syntax ([more-parsing (lambda (stx)
-                                         (debug "more parsing!!\n")
-                                         (parse stx))])
-              parsed
-              (more-parsing . rest)))))
-      #'(debug "regular parsing\n"))))
-
 ;; rest will be some subset of full
 (define (parsed-things full rest)
   (define full-datum (syntax->datum full))