diff --git a/README.md b/README.md
index bd7df3f..8628a1f 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ Unlike its Ruby Counterparts, `clj-libil` is only implemented as library.
 Just include this to fetch it from Clojars
 
 ```clojure
-[clj-libil "0.1.0"]
+[clj-libil "0.1.1"]
 ```
 
 ## Usage
@@ -38,6 +38,17 @@ There are 4 functions to convert word and sentences using `clj-libil`
 (convert-sentence-ngalam "Ngalup Ayabarus") ;; Pulang Surabaya
 ```
 
+## Release Notes
+
+### Version 0.1.1
+
+- Using `StringReader` to process token.
+- Using transient collection for optimisation.
+
+### Version 0.1.0
+
+- Initial Version
+
 ## License
 
 The MIT License (MIT)
diff --git a/project.clj b/project.clj
index d4122e2..872e031 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject clj-libil "0.1.0"
+(defproject clj-libil "0.1.1"
   :description "Clojure port of Libil, Processor of Bahasa Walikan"
   :url "http://github.com/lynxluna/clj-libil"
   :license {:name "MIT License"
diff --git a/src/libil/core.clj b/src/libil/core.clj
index 2f769c3..d647487 100644
--- a/src/libil/core.clj
+++ b/src/libil/core.clj
@@ -1,5 +1,6 @@
 (ns libil.core
-  (:use [clojure.string :only [split lower-case upper-case capitalize join]]))
+  (:use [clojure.string :only [split lower-case upper-case capitalize join]])
+  (:import [java.io Reader StringReader]))
 
 (def first-pair
   ["h" "n" "c" "r" "k" "d" "t" "s" "w" "l"])
@@ -13,15 +14,32 @@
 (defn- within? [coll item]
   ((complement nil?) (some (set [item]) coll)))
 
+(defn- rdr-peek
+  [^Reader rdr]
+  (.mark rdr 1)
+  (let [c (.read rdr)]
+    (.reset rdr)
+    c))
+
+(defn tokenize-rdr
+  "Tokenize a reader" 
+  [^Reader rdr]
+  (loop [tokens (transient [])
+         current (.read rdr)
+         ahead (rdr-peek rdr)]
+    (let [cc (-> current char str)]
+      (cond (== -1 ahead) (persistent! (conj! tokens cc))
+            (within? all-con (lower-case (str cc (char ahead))))
+              (let [pair (str (char current) (char ahead))]
+                (.skip rdr 1)
+                (if (== -1 (rdr-peek rdr)) (persistent! (conj! tokens pair))
+                    (recur (conj! tokens pair) (.read rdr) (rdr-peek rdr))))
+            :else (recur (conj! tokens cc) (.read rdr) (rdr-peek rdr))))))
+
 (defn tokenize-word
   "Tokenizing the word, to be able to be mapped"
   [^String w]
-  (loop [l [] rstr w]
-    (let [pair (apply str (take 2 rstr))
-          fstr (str (first rstr))]
-      (cond (empty? rstr) l
-            (within? all-con (lower-case pair)) (recur (conj l pair) (apply str (-> rstr rest rest)))
-            :else (recur (conj l fstr) (apply str (rest rstr)))))))
+  (tokenize-rdr (StringReader. w)))
 
 (defn- inv-cap 
   "Inverse Capitalize"