added performance tests

performance/run.lua

@@ -3,5 +3,41 @@ require 'middleclass'
 time = require 'performance/time'
 
 time('class creation', function()
-  local c = class('A')
+  local A = class('A')
+end)
+
+local A = class('A')
+
+time('instance creation', function()
+  local a = A:new()
+end)
+
+function A:foo()
+  return 1
+end
+
+local a = A:new()
+
+time('instance method invocation', function()
+  a:foo()
+end)
+
+local B = class('B', A)
+
+local b = B:new()
+
+time('inherited method invocation', function()
+  b:foo()
+end)
+
+function A.static:bar()
+  return 2
+end
+
+time('class method invocation', function()
+  A:bar()
+end)
+
+time('inherited class method invocation', function()
+  B:bar()
 end)

performance/time.lua

@@ -1,9 +1,13 @@
 return function(title, f)
 
-  local start = os.clock()
+  collectgarbage()
+
+  local startTime = os.clock()
 
   for i=0,10000 do f() end
 
-  print( title, os.clock() - start )
+  local endTime = os.clock()
+
+  print( title, endTime - startTime )
 
 end