Add base64 implementation by @dankogaiwq

Changelog

@@ -1,3 +1,6 @@
+intended v0.1.29
++ import base64
+
 v0.1.28
 + implement repeat
 + implement deepEqual

README.md

@@ -12,4 +12,5 @@ Acknowledgements
 - json.js taken from https://github.com/douglascrockford/JSON-js
 - trim taken from http://code.google.com/p/closure-library/source/browse/trunk/closure/goog/string/string.js?r=2
 - The following functions are taken from nodeunit - https://github.com/caolan/nodeunit, https://github.com/caolan/nodeunit/blob/master/LICENSE: deepEqual
+- base64.js implementation taken from @dankogai's https://github.com/dankogai/js-base64, MIT licensed
 

base64.js

@@ -0,0 +1,128 @@
+/*
+ * $Id: base64.js,v 1.2 2011/12/27 14:34:49 dankogai Exp dankogai $
+ *
+ *  Licensed under the MIT license.
+ *  http://www.opensource.org/licenses/mit-license.php
+ *
+ */
+
+(function(global){
+
+if (global.Base64) return;
+
+var b64chars 
+    = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
+var b64tab = function(bin){
+    var t = {};
+    for (var i = 0, l = bin.length; i < l; i++) t[bin.charAt(i)] = i;
+    return t;
+}(b64chars);
+
+var sub_toBase64 = function(m){
+    var n = (m.charCodeAt(0) << 16)
+          | (m.charCodeAt(1) <<  8)
+          | (m.charCodeAt(2)      );
+    return b64chars.charAt( n >>> 18)
+         + b64chars.charAt((n >>> 12) & 63)
+         + b64chars.charAt((n >>>  6) & 63)
+         + b64chars.charAt( n         & 63);
+};
+
+var toBase64 = function(bin){
+    if (bin.match(/[^\x00-\xFF]/)) throw 'unsupported character found' ;
+    var padlen = 0;
+    while(bin.length % 3) {
+        bin += '\0';
+        padlen++;
+    };
+    var b64 = bin.replace(/[\x00-\xFF]{3}/g, sub_toBase64);
+    if (!padlen) return b64;
+    b64 = b64.substr(0, b64.length - padlen);
+    while(padlen--) b64 += '=';
+    return b64;
+};
+
+var btoa = global.btoa || toBase64;
+
+var sub_fromBase64 = function(m){
+        var n = (b64tab[ m.charAt(0) ] << 18)
+            |   (b64tab[ m.charAt(1) ] << 12)
+            |   (b64tab[ m.charAt(2) ] <<  6)
+            |   (b64tab[ m.charAt(3) ]);
+    return String.fromCharCode(  n >> 16 )
+        +  String.fromCharCode( (n >>  8) & 0xff )
+        +  String.fromCharCode(  n        & 0xff );
+};
+
+var fromBase64 = function(b64){
+    b64 = b64.replace(/[^A-Za-z0-9\+\/]/g, '');
+    var padlen = 0;
+    while(b64.length % 4){
+        b64 += 'A';
+        padlen++;
+    }
+    var bin = b64.replace(/[A-Za-z0-9\+\/]{4}/g, sub_fromBase64);
+    if (padlen >= 2)
+        bin = bin.substring(0, bin.length - [0,0,2,1][padlen]);
+    return bin;
+};
+
+var atob = global.atob || fromBase64;
+
+var re_char_nonascii = /[^\x00-\x7F]/g;
+
+var sub_char_nonascii = function(m){
+    var n = m.charCodeAt(0);
+    return n < 0x800 ? String.fromCharCode(0xc0 | (n >>>  6))
+                     + String.fromCharCode(0x80 | (n & 0x3f))
+        :              String.fromCharCode(0xe0 | ((n >>> 12) & 0x0f))
+                     + String.fromCharCode(0x80 | ((n >>>  6) & 0x3f))
+                     + String.fromCharCode(0x80 |  (n         & 0x3f))
+        ;
+};
+
+var utob = function(uni){
+    return uni.replace(re_char_nonascii, sub_char_nonascii);
+};
+
+var re_bytes_nonascii
+    = /[\xC0-\xDF][\x80-\xBF]|[\xE0-\xEF][\x80-\xBF]{2}|[\xF0-\xF7][\x80-\xBF]{3}/g;
+
+var sub_bytes_nonascii = function(m){
+    var c0 = m.charCodeAt(0);
+    var c1 = m.charCodeAt(1);
+    if(c0 < 0xe0){
+        return String.fromCharCode(((c0 & 0x1f) << 6) | (c1 & 0x3f));
+    }else{
+        var c2 = m.charCodeAt(2);
+        return String.fromCharCode(
+            ((c0 & 0x0f) << 12) | ((c1 & 0x3f) <<  6) | (c2 & 0x3f)
+        );
+    }
+};
+
+var btou = function(bin){
+    return bin.replace(re_bytes_nonascii, sub_bytes_nonascii);
+};
+
+global.exports = {
+    fromBase64:fromBase64,
+    toBase64:toBase64,
+    atob:atob,
+    btoa:btoa,
+    utob:utob,
+    btou:btou,
+    encode:function(u){ return btoa(utob(u)) },
+    encodeURI:function(u){
+        return btoa(utob(u)).replace(/[+\/]/g, function(m0){
+            return m0 == '+' ? '-' : '_';
+        }).replace(/=+$/, '');
+    },
+    decode:function(a){ 
+        return btou(atob(a.replace(/[-_]/g, function(m0){
+            return m0 == '-' ? '+' : '/';
+        })));
+    }
+};
+
+})(module);