Use an atom instead of a ref for the entity ID generation.
closes #1
    
        | author | Steve Losh <steve@stevelosh.com> | 
    
        | date | Sat, 14 Jul 2012 14:35:05 -0400 | 
    
    
        | parents | 180b5b981d92 | 
    
        | children | c1fba0f3ec5f | 
    
        | branches/tags | (none) | 
    
        | files | src/caves/entities/core.clj | 
Changes
    
--- a/src/caves/entities/core.clj	Sat Jul 14 14:32:49 2012 -0400
+++ b/src/caves/entities/core.clj	Sat Jul 14 14:35:05 2012 -0400
@@ -1,7 +1,7 @@
 (ns caves.entities.core)
 
 
-(def ids (ref 0))
+(def ids (atom 0))
 
 (defprotocol Entity
   (tick [this world]
@@ -9,10 +9,7 @@
 
 
 (defn get-id []
-  (dosync
-    (let [id @ids]
-      (alter ids inc)
-      id)))
+  (swap! ids inc))
 
 
 (defn make-fnmap