doc mr-interaction

svn: r13897

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")))

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.}