From 63ba3f3d59f84a9857ec8ea28d18334d67eb5791 Mon Sep 17 00:00:00 2001
From: Colin Jones <trptcolin@gmail.com>
Date: Tue, 9 Feb 2010 12:57:08 +0800
Subject: [PATCH] adding about functions

---
 koans/about_functions.clj       | 21 +++++++++++++++++++++
 koans/path_to_enlightenment.clj |  1 +
 2 files changed, 22 insertions(+)
 create mode 100644 koans/about_functions.clj

diff --git a/koans/about_functions.clj b/koans/about_functions.clj
new file mode 100644
index 0000000..0c5aac3
--- /dev/null
+++ b/koans/about_functions.clj
@@ -0,0 +1,21 @@
+(defn count-items [& items]
+  (count items))
+
+(meditations
+  "Functions are often defined before they are used"
+  (= __ (count-items :a :b :c :d))
+
+  "But they can also be defined inline"
+  (= __ ((fn [n] (Math/pow n 10)) 2))
+
+  "Or using even shorter syntax"
+  (= __ (#(Math/pow % 10)))
+
+  "Functions can beget others"
+  (= __ (((fn []
+            (fn [a b] (+ a b))))
+          4 5))
+
+  "Higher-order functions take function arguments"
+  (= 25 ((fn [f] (f 5))
+          (fn [n] (__ __ __)))))
diff --git a/koans/path_to_enlightenment.clj b/koans/path_to_enlightenment.clj
index e0934f7..745524a 100644
--- a/koans/path_to_enlightenment.clj
+++ b/koans/path_to_enlightenment.clj
@@ -16,4 +16,5 @@
 (load "about_vectors")
 (load "about_sets")
 (load "about_maps")
+(load "about_functions")
 (println "You have acheived clojure enlightenment. Namaste.")