@humanwhocodes/doubly-linked-list - npm Package Compare versions

Comparing version 2.0.1 to 2.1.0

doubly-linked-list.js

@@ -395,3 +395,52 @@ /**
     }
+
+    /**
+     * Returns the first item that matches a given function.
+     * @param {Function} matcher A function returning true when an item matches
+     *      and false when an item doesn't match.
+     * @returns {*} The first item that returns true from the matcher, undefined
+     *      if no items match.
+     */
+    find(matcher) {
     
+        /*
+         * The `current` variable is used to iterate over the list nodes.
+         * It starts out pointing to the head and is overwritten inside
+         * of the loop below.
+         */
+        let current = this[head];
+
+        /*
+         * The `index` variable is used to track how deep into the list we've
+         * gone. This is important because this is the value that is returned
+         * from this method.
+         */
+        let index = 0;
+        
+        /*
+         * This loop checks each node in the list to see if it matches.
+         * If a match is found, it returns the data immediately, exiting the
+         * loop because there's no reason to keep searching. The search
+         * continues until there are no more nodes to search (when `current` is `null`).
+         */
+        while (current !== null) {
+            if (matcher(current.data)) {
+                return current.data;
+            }
+
+            // traverse to the next node in the list
+            current = current.next;
+
+            // keep track of where we are
+            index++;
+        }
+
+        /*
+         * If execution gets to this point, it means we reached the end of the
+         * list and didn't find `data`. Just return `undefined` as the 
+         * "not found" value.
+         */
+        return undefined;
+    }
+    
     /**
@@ -398,0 +447,0 @@ * Removes the node from the given location in the list.

package.json

 {
   "name": "@humanwhocodes/doubly-linked-list",
-  "version": "2.0.1",
+  "version": "2.1.0",
   "description": "A doubly linked list implementation in JavaScript",
@@ -5,0 +5,0 @@ "main": "doubly-linked-list.js",

README.md

@@ -14,4 +14,7 @@ # JavaScript Doubly Linked List Class
 1. Defining a `values()` generator method.
+1. Defining a `find()` method for searching the list.
 1. Returning `undefined` from `get()` when no such index exists.
 
+Read the [blog post](https://humanwhocodes.com/blog/2019/02/computer-science-in-javascript-doubly-linked-lists/) about the design of this class.
+
 ## Usage
@@ -46,2 +49,5 @@
 
+// search for a value
+let result = list.find(value => value.length > 3);
+
 // convert to an array using iterators
@@ -48,0 +54,0 @@ let array1 = [...list.values()];

No alert changes

Improved metrics

Total package byte prevSize

24432

increased by8.69%

Lines of code

559

increased by8.12%

Number of lines in readme file

75

increased by8.7%

No dependency changes