World now building correctly, and a simple printout function allows

a world to be inspected.

project.clj

@@ -3,4 +3,5 @@
   :url "http://example.com/FIXME"
   :license {:name "Eclipse Public License"
             :url "http://www.eclipse.org/legal/epl-v10.html"}
-  :dependencies [[org.clojure/clojure "1.5.1"]])
+  :dependencies [[org.clojure/clojure "1.5.1"]
+                 [org.clojure/math.combinatorics "0.0.7"]])

src/mw_engine/world.clj

@@ -1,4 +1,5 @@
-(ns mw-engine.world)
+(ns mw-engine.world
+  (:require [clojure.math.combinatorics :as combo]))
 
 (defn make-cell 
   "Create a default cell at x, y"
@@ -32,13 +33,33 @@
   (and (>= x 0)(>= y 0)(< y (count world))(< x (count (first world)))))
 
 (defn get-cell 
-  "Return the cell a x, y in this world, if any"
+  "Return the cell a x, y in this world, if any."
   [world x y]
   (cond (in-bounds world x y)
     (nth (nth world y) x)))
 
 (defn get-neighbours 
-  "Get the neighbours to distance depth of the cell at x, y in this world.
+  "Get the neighbours to distance depth of the cell at x, y in this world."
-   NOTE: this implementation is broken, it gets the diagonal"
   [world x y depth]
-  (map #(get-cell world %1 %2) (range (- x depth) (+ x depth)) (range (- y depth) (+ y depth))))
+  (map #(get-cell world (first %) (first (rest %))) 
+       (combo/cartesian-product 
+         (range (- x depth) (+ x depth)) 
+         (range (- y depth) (+ y depth)))))
+
+(defn truncate-state
+  "Truncate the print name of the state of this cell to at most limit characters."
+  [cell limit]
+  (let [s (:state cell)]
+    (cond (> (count (.toString s)) 10) (subs s 0 10)
+      true s)))
+
+(defn format-world-row
+  "Format one row in the state of a world for printing"
+  [row]
+  (apply str  
+         (map #(format "%10s" (truncate-state % 10)) row)))
+
+(defn print-world
+  "Print the current state of this world."
+  [world]
+  (dorun (map #(println (format-world-row %)) world)) nil)