changes

src/main.rs

@@ -72,7 +72,11 @@ impl Market {
 	    traders: Vec::new()
             }
         }
-        
+    fn register_trader(&mut self, name:&str) -> i32 {
+        let rval=self.traders.len() as i32;
+	self.traders.push(Trader::new(name,rval));
+	rval
+	}
     fn register_asset(&mut self, name:&str) -> i32 {
         self.asset_count+=1;
         self.asset_name2num.insert(String::from(name),self.asset_count);