leven - npm Package Compare versions

Comparing version 2.0.0 to 2.1.0

index.js

@@ -11,2 +11,11 @@ /* eslint-disable no-nested-ternary */
 
+	var swap = a;
+
+	// Swapping the strings if `a` is longer than `b` so we know which one is the
+	// shortest & which one is the longest
+	if (a.length > b.length) {
+		a = b;
+		b = swap;
+	}
+
 	var aLen = a.length;
@@ -23,2 +32,31 @@ var bLen = b.length;
 
+	// Performing suffix trimming:
+	// We can linearly drop suffix common to both strings since they
+	// don't increase distance at all
+	// Note: `~-` is the bitwise way to perform a `- 1` operation
+	while (aLen > 0 && (a.charCodeAt(~-aLen) === b.charCodeAt(~-bLen))) {
+		aLen--;
+		bLen--;
+	}
+
+	if (aLen === 0) {
+		return bLen;
+	}
+
+	// Performing prefix trimming
+	// We can linearly drop prefix common to both strings since they
+	// don't increase distance at all
+	var start = 0;
+
+	while (start < aLen && (a.charCodeAt(start) === b.charCodeAt(start))) {
+		start++;
+	}
+
+	aLen -= start;
+	bLen -= start;
+
+	if (aLen === 0) {
+		return bLen;
+	}
+
 	var bCharCode;
@@ -32,3 +70,3 @@ var ret;
 	while (i < aLen) {
-		charCodeCache[i] = a.charCodeAt(i);
+		charCodeCache[start + i] = a.charCodeAt(start + i);
 		arr[i] = ++i;
@@ -38,3 +76,3 @@ }
 	while (j < bLen) {
-		bCharCode = b.charCodeAt(j);
+		bCharCode = b.charCodeAt(start + j);
 		tmp = j++;
@@ -44,3 +82,3 @@ ret = j;
 		for (i = 0; i < aLen; i++) {
-			tmp2 = bCharCode === charCodeCache[i] ? tmp : tmp + 1;
+			tmp2 = bCharCode === charCodeCache[start + i] ? tmp : tmp + 1;
 			tmp = arr[i];
@@ -47,0 +85,0 @@ ret = arr[i] = tmp > ret ? tmp2 > ret ? ret + 1 : tmp2 : tmp2 > tmp ? tmp + 1 : tmp2;

package.json

 {
   "name": "leven",
-  "version": "2.0.0",
+  "version": "2.1.0",
   "description": "Measure the difference between two strings using the fastest JS implementation of the Levenshtein distance algorithm",
@@ -43,4 +43,4 @@ "license": "MIT",
   "devDependencies": {
-    "ava": "*",
-    "fast-levenshtein": "^1.0.3",
+    "ava": "^0.17.0",
+    "fast-levenshtein": "^2.0.5",
     "ld": "^0.1.0",
@@ -50,7 +50,8 @@ "levdist": "^2.0.0",
     "levenshtein-component": "0.0.1",
-    "levenshtein-edit-distance": "^1.0.0",
-    "matcha": "^0.6.0",
-    "natural": "^0.2.1",
-    "xo": "*"
+    "levenshtein-edit-distance": "^2.0.0",
+    "matcha": "^0.7.0",
+    "natural": "^0.4.0",
+    "talisman": "^0.18.0",
+    "xo": "^0.16.0"
   }
 }

readme.md

 # leven [![Build Status](https://travis-ci.org/sindresorhus/leven.svg?branch=master)](https://travis-ci.org/sindresorhus/leven)
 
-> Measure the difference between two strings  
+> Measure the difference between two strings<br>
 > The fastest JS implementation of the [Levenshtein distance](http://en.wikipedia.org/wiki/Levenshtein_distance) algorithm
@@ -17,3 +17,3 @@
 ```js
-var leven = require('leven');
+const leven = require('leven');
 
@@ -32,10 +32,11 @@ leven('cat', 'cow');
 ```
-         343,757 op/s » leven
-         264,625 op/s » levenshtein-edit-distance
-          49,981 op/s » fast-levenshtein
-          25,496 op/s » levenshtein-component
-          18,240 op/s » levdist
-          17,554 op/s » ld
-          12,633 op/s » natural
-           9,960 op/s » levenshtein
+         401,487 op/s » leven
+         371,707 op/s » talisman
+         264,191 op/s » levenshtein-edit-distance
+         152,923 op/s » fast-levenshtein
+          57,267 op/s » levenshtein-component
+          19,915 op/s » levdist
+          21,802 op/s » ld
+          18,079 op/s » natural
+          11,761 op/s » levenshtein
 ```
@@ -51,2 +52,2 @@
 
-MIT © [Sindre Sorhus](http://sindresorhus.com)
+MIT © [Sindre Sorhus](https://sindresorhus.com)

No alert changes

Improved metrics

Total package byte prevSize

4803

increased by24.17%

Lines of code

68

increased by78.95%

Number of lines in readme file

51

increased by2%

Worsened metrics

Dev dependency count

11

increased by10%

No dependency changes