From 77d1cfdb84c1b0ba41fc2598a1fd87a5d917adc7 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Mon, 2 Mar 2009 19:11:30 +0000
Subject: [PATCH] doc mr-interaction

svn: r13897
---
 collects/scribblings/quick/info.ss      |  3 ++-
 collects/scribblings/quick/mreval.scrbl | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 collects/scribblings/quick/mreval.scrbl

diff --git a/collects/scribblings/quick/info.ss b/collects/scribblings/quick/info.ss
index 699ae531b2..ba32a0f325 100644
--- a/collects/scribblings/quick/info.ss
+++ b/collects/scribblings/quick/info.ss
@@ -1,3 +1,4 @@
 #lang setup/infotab
 
-(define scribblings '(("quick.scrbl" () (getting-started 9))))
+(define scribblings '(("quick.scrbl" () (getting-started 9))
+                      ("mreval.scrbl")))
diff --git a/collects/scribblings/quick/mreval.scrbl b/collects/scribblings/quick/mreval.scrbl
new file mode 100644
index 0000000000..042cb9ccb5
--- /dev/null
+++ b/collects/scribblings/quick/mreval.scrbl
@@ -0,0 +1,21 @@
+#lang scribble/manual
+@(require (for-label scribble/eval "mreval.ss"))
+
+@title{Writing Examples with Pict Results}
+
+@defmodule[scribblings/quick/mreval]{The
+@schememodname[scribblings/quick/mreval] library support example
+evaluations with results that are @schememodname[slideshow] picts.}
+
+@defform[(mr-interaction datum ...)]{
+
+Like @scheme[interaction], but using an evaluator that includes
+@schememodname[scheme/gui/base] and @schememodname[slideshow]. 
+
+The trick is that @schememodname[scheme/gui] is not generally
+available when rendering documentation, because it requires a GUI
+context. The picture output is rendered to an image file when the
+@envvar{MREVAL} environment variable is set, so run the enclosing
+document once with the environment varibale to generate the
+images. Future runs (with the environment variable unset) use the
+generated image.}