Fix IE11 compatability with reduce polyfill.

bower.json

@@ -1,7 +1,7 @@
 {
   "name": "tribute",
   "description": "Native ES6 @mentions",
-  "version": "2.3.4",
+  "version": "2.3.5",
   "main": [
     "dist/tribute.js",
     "dist/tribute.css"

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tributejs",
-  "version": "2.3.4",
+  "version": "2.3.5",
   "description": "Native ES6 @mentions",
   "main": "dist/tribute.js",
   "devDependencies": {

src/utils.js

@@ -21,6 +21,70 @@ if (!Array.prototype.find) {
     }
 }
 
+// Production steps of ECMA-262, Edition 5, 15.4.4.21
+// Reference: http://es5.github.io/#x15.4.4.21
+// https://tc39.github.io/ecma262/#sec-array.prototype.reduce
+if (!Array.prototype.reduce) {
+  Object.defineProperty(Array.prototype, 'reduce', {
+    value: function(callback /*, initialValue*/) {
+      if (this === null) {
+        throw new TypeError( 'Array.prototype.reduce ' + 
+          'called on null or undefined' );
+      }
+      if (typeof callback !== 'function') {
+        throw new TypeError( callback +
+          ' is not a function');
+      }
+
+      // 1. Let O be ? ToObject(this value).
+      var o = Object(this);
+
+      // 2. Let len be ? ToLength(? Get(O, "length")).
+      var len = o.length >>> 0; 
+
+      // Steps 3, 4, 5, 6, 7      
+      var k = 0; 
+      var value;
+
+      if (arguments.length >= 2) {
+        value = arguments[1];
+      } else {
+        while (k < len && !(k in o)) {
+          k++; 
+        }
+
+        // 3. If len is 0 and initialValue is not present,
+        //    throw a TypeError exception.
+        if (k >= len) {
+          throw new TypeError( 'Reduce of empty array ' +
+            'with no initial value' );
+        }
+        value = o[k++];
+      }
+
+      // 8. Repeat, while k < len
+      while (k < len) {
+        // a. Let Pk be ! ToString(k).
+        // b. Let kPresent be ? HasProperty(O, Pk).
+        // c. If kPresent is true, then
+        //    i.  Let kValue be ? Get(O, Pk).
+        //    ii. Let accumulator be ? Call(
+        //          callbackfn, undefined,
+        //          « accumulator, kValue, k, O »).
+        if (k in o) {
+          value = callback(value, o[k], k, o);
+        }
+
+        // d. Increase k by 1.      
+        k++;
+      }
+
+      // 9. Return accumulator.
+      return value;
+    }
+  });
+}
+
 (function() {
 
     if (typeof window.CustomEvent === "function") return false

tributejs.d.ts

@@ -1,4 +1,4 @@
-// Type definitions for TributeJS v2.3.4
+// Type definitions for TributeJS v2.3.5
 // Project: https://github.com/zurb/tribute
 // Definitions by: Jordan Humphreys <https://github.com/mrsweaters/>