diff --git a/typo/typo.js b/typo/typo.js
index 9da598d1..32457afd 100644
--- a/typo/typo.js
+++ b/typo/typo.js
@@ -794,41 +794,39 @@ Typo.prototype = {
 		*/
 		
 		function edits1(words) {
-			var rv = [];
+			var rv = new WordList();
 			
-			var ii, i, j, _iilen, _len, _jlen;
+			var i, j,  _len, _jlen;
 			
-			for (ii = 0, _iilen = words.length; ii < _iilen; ii++) {
-				var word = words[ii];
-				
+            words.forEach(function (word) {
 				for (i = 0, _len = word.length + 1; i < _len; i++) {
 					var s = [ word.substring(0, i), word.substring(i) ];
 				
 					if (s[1]) {
-						rv.push(s[0] + s[1].substring(1));
+						rv.add(s[0] + s[1].substring(1));
 					}
 					
 					// Eliminate transpositions of identical letters
 					if (s[1].length > 1 && s[1][1] !== s[1][0]) {
-						rv.push(s[0] + s[1][1] + s[1][0] + s[1].substring(2));
+						rv.add(s[0] + s[1][1] + s[1][0] + s[1].substring(2));
 					}
 
 					if (s[1]) {
 						for (j = 0, _jlen = self.alphabet.length; j < _jlen; j++) {
 							// Eliminate replacement of a letter by itself
 							if (self.alphabet[j] != s[1].substring(0,1)){
-								rv.push(s[0] + self.alphabet[j] + s[1].substring(1));
+								rv.add(s[0] + self.alphabet[j] + s[1].substring(1));
 							}
 						}
 					}
 
 					if (s[1]) {
 						for (j = 0, _jlen = self.alphabet.length; j < _jlen; j++) {
-							rv.push(s[0] + self.alphabet[j] + s[1]);
+							rv.add(s[0] + self.alphabet[j] + s[1]);
 						}
 					}
 				}
-			}
+			});
 			
 			return rv;
 		}
@@ -836,21 +834,22 @@ Typo.prototype = {
 		function known(words) {
 			var rv = [];
 			
-			for (var i = 0, _len = words.length; i < _len; i++) {
-				if (self.check(words[i])) {
-					rv.push(words[i]);
-				}
-			}
+            words.forEach(function(word) {
+                if (self.checkExact(word)){
+                    rv.push(word)
+                }
+            })
 			
 			return rv;
 		}
 		
 		function correct(word) {
 			// Get the edit-distance-1 and edit-distance-2 forms of this word.
-			var ed1 = edits1([word]);
+			var ed1 = edits1(new WordList([word]));
 			var ed2 = edits1(ed1);
+            ed1.forEach(function(word) { ed2.add(word) });
 			
-			var corrections = known(ed1.concat(ed2));
+			var corrections = known(ed2);
 			
 			var i, _len;
 			
@@ -919,9 +918,47 @@ Typo.prototype = {
 		return this.memoized[word]['suggestions'];
 	}
 };
+
+// WordList object
+var WordList = function (initial) {
+  var self = this;
+
+  if (typeof (Set) === 'undefined') {
+    var index = {};
+    var words = [];
+
+    self.add = function (v) {
+      if (!(v in index)) {
+        index[v] = v
+        words.push(v)
+      }
+    }
+
+    self.forEach = function (fn) {
+      for (var i = 0; i < words.length; i++) {
+        fn(words[i], i, words)
+      }
+    }
+  } else {
+    var set = new Set()
+
+    self.add = function (v) { set.add(v) }
+
+    self.forEach = function (fn) { set.forEach(fn) }
+  }
+
+  if (initial) {
+    for (var i = 0; i < initial.length; i++) {
+      self.add(initial[i])
+    }
+  }
+
+  return self
+}
+
 })();
 
 // Support for use as a node.js module.
 if (typeof module !== 'undefined') {
 	module.exports = Typo;
-}
\ No newline at end of file
+}