1 files changed, 57 insertions, 0 deletions
diff --git a/doc/examples/shadow.m4 b/doc/examples/shadow.m4
new file mode 100644
index 00000000..f13b7dfa
--- /dev/null
+++ b/doc/examples/shadow.m4
@@ -0,0 +1,57 @@
+dnl Copyright (C) 2006, 2010, 2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it
+dnl with or without modifications, as long as this notice is preserved.
+# no modules loaded yet
+test
+shadow
+
+# define our own macros for `test' and `shadow'
+define(`test', `local::`test'')
+define(`shadow', `local::`shadow'')
+test
+shadow
+
+# module Shadow defines `shadow' and `test' macros
+load(`shadow')
+dumpdef(`test')
+dumpdef(`shadow')
+test
+shadow
+
+# save the definition of `test' from the Shadow module
+define(`Shadow::test', defn(`test'))
+
+# module Test also defines a `test' macro
+load(`modtest')
+dumpdef(`test')
+dumpdef(`shadow')
+test
+shadow
+
+# Reloading Shadow shouldn't affect anything
+load(`shadow')
+dumpdef(`test')
+dumpdef(`shadow')
+test
+shadow
+
+# Unloading Test will unshadow the test definition in Shadow
+unload(`modtest')
+dumpdef(`test')
+dumpdef(`shadow')
+test
+shadow
+
+# Unloading Shadow once has no effect (we loaded it twice)
+unload(`shadow')
+dumpdef(`test')
+dumpdef(`shadow')
+test
+shadow
+
+# Unloading Shadow again will revert to copying `test' and the local
+# `shadow' macro.
+unload(`shadow')
+test
+shadow