From 02bc968e0cec04db2c2b6e02c08decedb8e8e8dc Mon Sep 17 00:00:00 2001
From: darkf <lw9k123@gmail.com>
Date: Wed, 12 Feb 2014 02:54:41 -0800
Subject: [PATCH] add ref example

---
 examples/ref.lamb | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 examples/ref.lamb

diff --git a/examples/ref.lamb b/examples/ref.lamb
new file mode 100644
index 0000000..d13b90e
--- /dev/null
+++ b/examples/ref.lamb
@@ -0,0 +1,16 @@
+-- Refs are global mutable (changing) values.
+-- They let you break referential transparency (purity) to make some things easier.
+
+x = ref!(1337). -- Construct a new ref, set to the value 1337
+print(x). -- Should print <ref>
+print(readRef!(x)). -- Should print 1337
+
+setRef!(x, 42). -- Set it to 42
+print(readRef!(x)).
+
+-- Apply a function on the current value in the reference and set it to the new value.
+modifyRef!(ref, f) ->
+	setRef!(ref, f(readRef!(ref))).
+
+modifyRef!(x, \v -> v*2). -- Double x
+print(readRef!(x)). -- 84