From 0af8f1aeeb9bcd7affe04df9a62fd7aaac20386b Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Wed, 30 Aug 2017 07:37:35 -0700
Subject: [PATCH] correct missing `datum?`

---
 beautiful-racket-lib/br/datum.rkt            | 2 +-
 beautiful-racket-lib/br/scribblings/br.scrbl | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/beautiful-racket-lib/br/datum.rkt b/beautiful-racket-lib/br/datum.rkt
index b4c0b66..38e0275 100644
--- a/beautiful-racket-lib/br/datum.rkt
+++ b/beautiful-racket-lib/br/datum.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(provide format-datum format-datums)
+(provide format-datum format-datums datum?)
 
 (define (blank? str)
   (for/and ([c (in-string str)])
diff --git a/beautiful-racket-lib/br/scribblings/br.scrbl b/beautiful-racket-lib/br/scribblings/br.scrbl
index a590632..870202f 100644
--- a/beautiful-racket-lib/br/scribblings/br.scrbl
+++ b/beautiful-racket-lib/br/scribblings/br.scrbl
@@ -66,9 +66,9 @@ When I use ``datum'' in its specific Racket sense, I use ``datums'' as its plura
 
 @defproc[
 (format-datum
-[datum-form (or/c list? symbol?)]
+[datum-form datum?]
 [val any/c?] ...)
-(or/c list? symbol?)]{
+(or/c datum? void?)]{
 Similar to @racket[format], but the template @racket[datum-form] is a datum, rather than a string, and the function returns a datum, rather than a string. Otherwise, the same formatting escapes can be used in the template (see @racket[fprintf]).
 
 Two special cases. First, a string that describes a list of datums is parenthesized so the result is a single datum. Second, an empty string returns @racket[void] (not @racket[#f], because that's a legitimate datum).