diff --git a/functions.lisp b/functions.lisp
index 81a34dc..4c7bb81 100644
--- a/functions.lisp
+++ b/functions.lisp
@@ -10,6 +10,18 @@
 (defparameter *green*  (color 1 32))
 (defparameter *yellow* (color 0 33))
 
+;; simple hash function (Fowler Noll Vo)
+;; https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function
+(defun fnv-hash(string)
+  "return a hash from a string"
+  (let ((FNV_prime 2)
+        (hash 26123230013))
+    (loop for octet-of-data across string
+       do
+         (setf hash (* FNV_prime
+                       (logxor hash (char-code octet-of-data)))))
+    hash))
+
 ;; common-lisp don't have a split string function natively
 (defun replace-all (string part replacement &key (test #'char=))
   (with-output-to-string (out)
@@ -72,8 +84,9 @@
      (or ,@body)))
 
 (defun =>(level fonction &rest params)
-  (format t "[~a~a ~20A~a] ~35A" *yellow* level fonction *white* (getf params :desc params))
-  (let ((result (funcall fonction params)))
+  (format t "[~a~a ~20A~a] ~45A" *yellow* level fonction *white* (getf params :desc params))
+  (let ((hash (fnv-hash (format nil "~{~a~}" (nconc (list level fonction) (remove-if #'symbolp params)))))
+        (result (funcall fonction params)))
     (if (not (listp result))
         (progn
           (format t " => ~asuccess~a~%" *green* *white*)