From f30922a7dc27494f6ab401e20974e0b272b1ae06 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Fri, 2 Sep 2016 11:42:38 -0700
Subject: [PATCH] add `verbose-app`

---
 beautiful-racket-lib/br/verbose-app.rkt | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 beautiful-racket-lib/br/verbose-app.rkt

diff --git a/beautiful-racket-lib/br/verbose-app.rkt b/beautiful-racket-lib/br/verbose-app.rkt
new file mode 100644
index 0000000..f5cd4e1
--- /dev/null
+++ b/beautiful-racket-lib/br/verbose-app.rkt
@@ -0,0 +1,10 @@
+#lang br
+(require (prefix-in br: (only-in br #%app)))
+(provide #%app)
+
+(define-macro (#%app APP ARG ...)
+  #'(let ()
+      (br:#%app displayln (br:#%app format "handling subexpressions in ~a" '(APP ARG ...)))
+      (define result (br:#%app APP ARG ...))
+      (br:#%app displayln (br:#%app format "evaluating ~a = ~a" '(APP ARG ...) result ))
+      result))