From a2f430020abbed14f887c2384a67aef04479111c Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Fri, 2 Oct 2015 15:15:31 -0600
Subject: [PATCH] scribble/eval: strip away `code:contract`s

Make `code:contract` handled like `code:comment` for evaluation.

Relevant to PR 15161
---
 scribble-doc/scribblings/scribble/eval.scrbl | 2 +-
 scribble-lib/scribble/eval.rkt               | 8 ++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/scribble-doc/scribblings/scribble/eval.scrbl b/scribble-doc/scribblings/scribble/eval.scrbl
index 8d20d725..b781ed2b 100644
--- a/scribble-doc/scribblings/scribble/eval.scrbl
+++ b/scribble-doc/scribblings/scribble/eval.scrbl
@@ -49,7 +49,7 @@ Certain patterns in @racket[datum] are treated specially:
        @racket[(@#,indexed-racket[code:line] _code-datum (@#,racketidfont{code:comment} _comment-datum ...))]
        is treated as @racket[_code-datum] for evaluation.}
 
- @item{Other uses of @racketidfont{code:comment} and
+ @item{Other uses of @racketidfont{code:comment}, @racketidfont{code:contract}, and
        @racketidfont{code:blank} are stripped from each @racket[datum]
        before evaluation.}
 
diff --git a/scribble-lib/scribble/eval.rkt b/scribble-lib/scribble/eval.rkt
index ea3c81fb..c48b22fb 100644
--- a/scribble-lib/scribble/eval.rkt
+++ b/scribble-lib/scribble/eval.rkt
@@ -206,11 +206,13 @@
 
 (define (extract-to-evaluate s)
   (let loop ([s s] [expect #f])
-    (syntax-case s (code:line code:comment eval:alts eval:check)
+    (syntax-case s (code:line code:comment code:contract eval:alts eval:check)
       [(code:line v (code:comment . rest))
        (loop (extract s cdr car) expect)]
       [(code:comment . rest)
        (values (nothing-to-eval) expect)]
+      [(code:contract . rest)
+       (values (nothing-to-eval) expect)]
       [(eval:alts p e)
        (loop (extract s cdr cdr car) expect)]
       [(eval:check e expect)
@@ -346,8 +348,10 @@
      (define (comment? a)
        (and (pair? a)
             (or (eq? (car a) 'code:comment)
+                (eq? (car a) 'code:contract)
                 (and (identifier? (car a))
-                     (eq? (syntax-e (car a)) 'code:comment)))))
+                     (or (eq? (syntax-e (car a)) 'code:comment)
+                         (eq? (syntax-e (car a)) 'code:contract))))))
      (if (or (comment? a) (and (syntax? a) (comment? (syntax-e a))))
        (strip-comments (cdr stx))
        (cons (strip-comments a)