Declare regexps and functions outside of naturalSort() - speed increased by ~12%

Author: duzun

naturalSort.js

@@ -16,30 +16,32 @@
   : define
 )
 /*define*/([], function factory() {
-
-function naturalSort (a, b) {
     var re = /(^([+\-]?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?(?=\D|\s|$))|^0x[\da-fA-F]+$|\d+)/g,
         sre = /^\s+|\s+$/g,   // trim pre-post whitespace
         snre = /\s+/g,        // normalize all whitespace to single ' ' character
         dre = /(^([\w ]+,?[\w ]+)?[\w ]+,?[\w ]+\d+:\d+(:\d+)?[\w ]?|^\d{1,4}[\/\-]\d{1,4}[\/\-]\d{1,4}|^\w+, \w+ \d+, \d{4})/,
         hre = /^0x[0-9a-f]+$/i,
         ore = /^0/,
+        b0re = /^\0/,
+        e0re = /\0$/,
         i = function(s) {
             return (naturalSort.insensitive && ('' + s).toLowerCase() || '' + s).replace(sre, '');
         },
+        normChunk = function(s, l) {
+            // normalize spaces; find floats not starting with '0', string or 0 if not defined (Clint Priest)
+            return (!s.match(ore) || l == 1) && parseFloat(s) || s.replace(snre, ' ').replace(sre, '') || 0;
+        };
+
+function naturalSort (a, b) {
         // convert all to strings strip whitespace
-        x = i(a),
-        y = i(b),
+    var x = i(a) || '',
+        y = i(b) || '',
         // chunk/tokenize
-        xN = x.replace(re, '\0$1\0').replace(/\0$/,'').replace(/^\0/,'').split('\0'),
-        yN = y.replace(re, '\0$1\0').replace(/\0$/,'').replace(/^\0/,'').split('\0'),
+        xN = x.replace(re, '\0$1\0').replace(e0re,'').replace(b0re,'').split('\0'),
+        yN = y.replace(re, '\0$1\0').replace(e0re,'').replace(b0re,'').split('\0'),
         // numeric, hex or date detection
         xD = parseInt(x.match(hre), 16) || (xN.length !== 1 && Date.parse(x)),
         yD = parseInt(y.match(hre), 16) || xD && y.match(dre) && Date.parse(y) || null,
-        normChunk = function(s, l) {
-            // normalize spaces; find floats not starting with '0', string or 0 if not defined (Clint Priest)
-            return (!s.match(ore) || l == 1) && parseFloat(s) || s.replace(snre, ' ').replace(sre, '') || 0;
-        },
         oFxNcL, oFyNcL;
     // first try and sort Hex codes or Dates
     if (yD) {