Add sample template

sample-template.clj

@@ -0,0 +1,57 @@
+(use 'packer.model)
+(require 'packer.util)
+
+; Define some useful function
+; to provide a constant number of items.
+(defn x [n] (fn [_] n))
+
+; Define a store - the single source
+; of truth of all items from which
+; we are going to choose what we want to pack.
+; The items are grouped by categories.
+(def store {
+  :cloths [
+    (->Item :t-shirt #(/ % 4))
+  ]
+
+  :electronics [
+    (->Item :smartphone (x 1))
+    (->Item :tablet (x 1))
+    (->Item :laptop (x 1))
+  ]
+})
+
+; Define the display names for each
+; item, category and question.
+(def i18n {
+  :nights? "How many nights?"
+  :tablet? "Do you need your tablet there?"
+  :laptop? "Do you need your laptop there?"
+  :electronics "Electronics"
+  :cloths "Cloths"
+  :t-shirt "T-shirt"
+  :smartphone "Smartphone"
+  :tablet "Tablet"
+  :laptop "Laptop"
+})
+
+; Define some utility function
+; to generate preset basing on some question
+(defn preset [question items seq] 
+  (if (packer.util/ask-bool (get i18n question))
+    (concat seq items)
+    seq))
+
+; Define profile - a function which takes
+; a number of provided nights and produces
+; the sequence of all items which should
+; be in the target list. If the sequence is empty
+; no item will be produced on the target list.
+(defn profile [nights] 
+  (->> [:smartphone :t-shirt]
+      (preset :tablet? [:tablet])
+      (preset :laptop? [:laptop])))
+
+; Wrap it up together. It should be
+; the last expression in the file.
+(->Template store i18n profile)