 Courses from Guy Bedford

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.

javascript

We demonstrate how to build a WebAssembly module that depends on malloc, linking in a pre-built malloc implementation at runtime, using a JS binding trick to handle the circular reference between the two WebAssembly modules. We then optimize the load process to ensure we are fetching these modules in parallel.

Malloc implementation: https://github.com/guybedford/wasm-stdlib-hack/blob/master/dist/memory.wasm

WASM Fiddle: https://wasdk.github.io/WasmFiddle/?1feerp

Demo Repo: https://github.com/guybedford/wasm-intro

Allocate Dynamic Memory in WebAssembly with Malloc

Starting from the previous example, we rebuild the program code to import its memory instead of exporting it. We then use this to simplify the application loading code.

Emscripten: https://kripken.github.io/emscripten-site/

Demo Repo: https://github.com/guybedford/wasm-intro

Create and Import a WebAssembly Memory

Using the previous JS example (with some polishing), we start the conversion by copying the JS code into a C file. Step-by-step we run through the principles of converting this JS code into valid C code that we can compile into Web Assembly, based on the same principles we learnt in the initial lessons. We paste the C code into WASM Fiddle to get the resulting WebAssembly binary, and wire it into the application.

Demo repo: https://github.com/guybedford/wasm-demo

_Note the demo is currently only supported in Chrome Canary with the Experimental Web Platform flag (chrome://flags/#enable-experimental-web-platform-feature) enabled due to the use of ES modules and WebGL 2.0._

Step-by-Step JS to WebAssembly Conversion

To improve the performance of collision detection, we need to dive into the internals of the algorithm. Here we update the JS collision detection code to use a grid for collision detection, which brings a big performance boost at the end.

Demo repo: https://github.com/guybedford/wasm-demo

_Note the demo is currently only supported in Chrome Canary with the Experimental Web Platform flag (chrome://flags/#enable-experimental-web-platform-feature) enabled due to the use of ES modules and WebGL 2.0._

Optimize Collision Detection in JS with a Grid

To write a grid collision detection optimization in C requires thinking about the data structure of the grid more than in JS. In C we can represent this with a linked list and show how to convert the JS optimization code into this structure. When we compare the final performance, the WebAssembly code is now faster than the JS code - being able to write a low-level, more efficient data structure in memory is what gives WebAssembly its best advantage over JS. For those new to the principles, a good introduction to data structures and algorithms is the CLRS Introduction to Algorithms book.

Demo repo: https://github.com/guybedford/wasm-demo

_Note the demo is currently only supported in Chrome Canary with the Experimental Web Platform flag (chrome://flags/#enable-experimental-web-platform-feature) enabled due to the use of ES modules and WebGL 2.0._

Surpass JS Performance with Optimized Collision Detection in WASM using a Linked List Grid

We use the C language instead of pure WAST to create a square root function using WASM Fiddle (https://wasdk.github.io/WasmFiddle//). We show how to run the WebAssembly in WASM Fiddle, then download and run it in the browser using a helper function to load the WebAssembly.

WASM Fiddle: https://wasdk.github.io/WasmFiddle/?t96rp

Demo Repo: https://github.com/guybedford/wasm-intro

Compile C Code into WebAssembly

We use an offset exporting function to get the address of a string in WebAssembly memory. We then create a typed array on top of the WebAssembly memory representing the raw string data, and decode that into a JavaScript string.

WASM Fiddle: https://wasdk.github.io/WasmFiddle/?6wzgh

Demo Repo: https://github.com/guybedford/wasm-intro

Read WebAssembly Memory from JavaScript

This lesson demonstrates a full build of LLVM roughly following the steps in [GettingStarted.html](http://llvm.org/docs/GettingStarted.html) (or [GettingStartedVS.html](http://llvm.org/docs/GettingStartedVS.html) for Windows), but with the experimental WebAssembly target build option. Prerequisites include cmake (which can be downloaded from [cmake.org/download](https://cmake.org/download/)), Visual Studio on windows, or Xcode command line tools on mac.

Clone and Build LLVM with the Experimental WebAssembly Target

In this lesson we cover the install process for Binaryen (http://github.com/WebAssembly/binaryen) to get the s2wasm binary and WABT (https://github.com/WebAssembly/wabt) to get the wast2wasm binary.

Prerequisites are cmake (https://cmake.org/download/), XCode CLI tools on Mac, or Visual Studio on Windows.

Install Binaryen and the WebAssembly Binary Toolkit (WABT)

We write a function that converts a string to lowercase in WebAssembly, demonstrating how to set the input string from JavaScript.

WASM Fiddle: https://wasdk.github.io/WasmFiddle/?h1s69

Demo Repo: https://github.com/guybedford/wasm-intro

Write to WebAssembly Memory from JavaScript

We introduce a black-box render function which draws circles to the screen, explaining how the position information is represented in the memory for the renderer (a typed array of [x1, y1, r1, x2, y2, r2, …]). We draw a simple circle (at [0, 0, 100]), then many random circles to get a feel for passing rendering data by directly setting Typed Array memory. The details of the renderer are not discussed at all. We set up some simple dynamics and wall bounds, and then push the circle count up over 1,000,000 renders to demonstrate the performance of dealing with raw memory and WebGL.

Demo repo: https://github.com/guybedford/wasm-demo

_Note the demo is currently only supported in Chrome Canary with the Experimental Web Platform flag (chrome://flags/#enable-experimental-web-platform-feature) enabled due to the use of ES modules and WebGL 2.0._

Typed Arrays in High Performance JavaScript

To compare the performance between JS and WebAssembly, we use an example that calculates the collisions between circles on the screen. This quickly slows down the rendering performance making the performance comparison visible. We briefly go over the same steps of converting JS into C code, and find that the JS version of the code is actually faster than the WASM version - WebAssembly improving performance is not such a simple argument.

Demo repo: https://github.com/guybedford/wasm-demo

_Note the demo is currently only supported in Chrome Canary with the Experimental Web Platform flag (chrome://flags/#enable-experimental-web-platform-feature) enabled due to the use of ES modules and WebGL 2.0._

A First Comparison of the Performance between JS and WebAssembly

We go through the command-line steps to compile C/C++ via LLVM into an intermediate S file, then use Binaryen to compile that S file into a WAST file and finally WABT to get the WASM binary. We then show an approach to clone and configure a custom std library headers for Web Assembly to build includes to the standard library.

Compiling C/C++ to WebAssembly using LLVM, Binaryen and WABT

In this introduction, we show a simple WebAssembly function that returns the square root of a number. To create this function we load up WebAssembly Explorer (https://mbebenita.github.io/WasmExplorer/), writing the native WAST code to create and export the function. We compile and download the resulting WebAssembly binary, loading this with the Fetch API and WebAssembly JavaScript API to call the function in the browser.

Demo Repo: https://github.com/guybedford/wasm-intro

Create and Run a Native WebAssembly Function

Using WASM Fiddle, we show how to write a simple number logger function that calls a consoleLog function defined in JavaScript. We then download and run the same function in a local project.

WASM Fiddle: https://wasdk.github.io/WasmFiddle/?cvrmt

Demo Repo: https://github.com/guybedford/wasm-intro

Call a JavaScript Function from WebAssembly

This course begins with some small steps for working with WebAssembly straight away using online tools wasm Explorer and wasm Fiddle to try out the examples in the browser. We start by calling a WebAssembly function from JS, then a JS function from WebAssembly, then go on to reading and writing WebAssembly memory from JS. To move beyond these online sandboxes, we show the exact steps for setting up and running a complete local WebAssembly build workflow using the experimental LLVM WebAssembly build target. We then take a demo WebGL application written in JS and show how we can optimize this with WebAssembly to get a real world example of a WebAssembly performance improvement, although it isn’t as obvious a process as we might have hoped.

Get Started Using WebAssembly (wasm)

Creating powerful and context-aware tools for Cursor IDE becomes straightforward when leveraging information directly from your current project. In this lesson, you'll learn how to build a custom MCP (model context protocol) tool that intelligently requests essential details—such as the current project path and conversation summaries—from your Cursor project.

Workflow demonstrated in this lesson:

- Define MCP tool parameters to request specific project details.
- Pass project path and conversation summaries into your MCP tool.
- Automatically write or update files within your current project using these parameters.

Key benefits:

- Automate tasks with precision based on your active project's context.
- Simplify interactions by creating AI-driven CLI commands tailored to your needs.
- Open endless possibilities for integrating external APIs and advanced automation.

Through this practical demonstration, you'll gain a versatile technique for enhancing your development workflow in Cursor IDE.

[https://github.com/johnlindquist/mcp-cursor-tool-starter](https://github.com/johnlindquist/mcp-cursor-tool-starter)

John Lindquist

Build MCP Tools Using Project Context for Custom Cursor IDE Automation

Setting up custom MCP (Machine Command Protocol) servers in Cursor can involve tedious steps, such as configuring node paths or referencing additional commands. This lesson shows how to streamline this process by bundling your MCP server directly into a standalone executable.

Workflow demonstrated in this lesson:

- Use a simple MCP server project starter.
- Run a single bundling command to create an executable.
- Right-click the generated executable, copy its full path, and add that directly to your Cursor settings.

Key benefits:

- Eliminates the need for complex node path configurations.
- Simplifies the setup and integration of custom MCP servers into Cursor.
- Makes the server executable instantly accessible within your Cursor environment.

By following this streamlined approach, you can quickly and easily integrate custom MCP servers into Cursor, making your development workflow cleaner and more efficient.

[https://github.com/johnlindquist/mcp-cursor-tool-starter]()

Easy MCP Server Setup in Cursor IDE with Bundled Executables

TanStack Router is the foundation for TanStack Start, which is gaining significant attention due to its innovative approach to application development.

This course focuses on getting effective TanStack Router, a modern and scalable routing solution for React applications. You will learn how to:
- set up and scaffold new applications,
- use file-based routing
- create nested routes
- manage dynamic route parameters and more.

The course covers advanced features like route loaders, caching strategies, and lifecycle hooks, which are crucial for enhancing application performance and user experience.

By understanding TanStack Router, you can build more efficient, type-safe, and maintainable applications, leveraging its integration with data fetching libraries like TanStack Query.

This knowledge is essential for developers looking to improve their routing skills and stay ahead in the field.

Tomasz Ducin

Up and Running with Tanstack Router and React

Learn TanStack Router for React: set up apps, use file-based routing, manage routes, and boost app performance.


In this lesson, we explore how TanStack Router integrates with the [native browser history API](https://developer.mozilla.org/en-US/docs/Web/API/History) to manage navigation.

As we navigate through different routes, the URL changes are stored in the browser's history, allowing users to use the forward and backward buttons to traverse their navigation history.

This functionality also **enables permalinks**, meaning users can copy and paste URLs to access specific routes directly.

Additionally, we learn how to programmatically interact with the history object to move forward or backward through the navigation stack, enhancing the user experience by providing full control over navigation actions.

This compatibility with the native history API ensures that TanStack Router applications behave similarly to traditional websites, offering a seamless and intuitive user experience.

Browse History in Tanstack Router

Browse history in TanStack React Router using the native history API for seamless navigation

In this lesson, we explore how to hook into TanStack Router's lifecycle hooks to execute custom logic during route changes.

The hooks we'll look into are: `onEnter`, `onStay`, and `onLeave`, which are triggered when entering, staying within, or leaving a route, respectively.

All hooks receive a detailed match parameter, providing information about the route's path, ID, and tons of other details.

This allows for the implementation of features like animations or logging when navigating between routes.

We also learn how to use these hooks to track and manage state changes as users interact with the application, making it easier to implement complex behaviors based on route transitions.

Hook into Route Lifecycle Hooks in Tanstack Router

Hook into TanStack React Router's lifecycle hooks for custom route logic and animations.

In this lesson, we learn how to handle not found errors in TanStack Router by using the `notFoundComponent` at both nested and global levels.

To trigger the display of a `notFoundComponent`, we must throw a specific error using the `notFound` function within a loader or other lifecycle method of a route. This approach allows us to provide custom error messages for specific routes or globally across the application.

We explore how to define a notFoundComponent within a specific route's configuration and how to set a `defaultNotFoundComponent` at the router global level, which applies to all routes unless overridden locally. This flexibility ensures that users receive meaningful feedback when encountering non-existent routes.

Provide NotFoundComponent at Nested Route or Global Level in Tanstack Router

Handle notFound errors in TanStack Router with notFoundComponent at nested or global levels.



In this lesson, we learn how to access dynamic route parameters using the `useParams` hook in TanStack Router.

When used with a specific `Route` object, `useParams` provides type-safe access to route parameters, ensuring that TypeScript knows the exact types of these parameters.

This approach eliminates the possibility of undefined/optional values, making it safer for accessing parameters like `employeeId`.

However, when using `useParams` globally without specifying a route, it requires an options object with `{ strict: false }`, which reduces type safety.

In this case, the hook can access parameters from any route in the application, but it does not guarantee their existence or type. This flexibility allows components to be reused across different routes, but it requires careful handling of potential errors.



Access Dynamic Route Parameters with useParams in Tanstack Router

Access dynamic route parameters with useParams in TanStack React Router for type-safe routing.

In this lesson, we learn how to reorganize file-based routes in TanStack Router to accommodate nested routing structures.

We explore how to create additional nested routes by converting files into directories, allowing for further nesting.

For example, to create a nested route like `/employees/$employeeId/edit`, we can create a **directory** (!) named `$employeeId` and place an `index.tsx` file inside it to define the route component for this nested route.

This approach provides flexibility in organizing files while maintaining the convention that file names and locations align with route paths. We also see how to adapt existing components and loaders to work with these reorganized routes, enabling features like edit forms or delete actions (or whatever) within nested routes.


Reorganize File-Based Routes in Tanstack Router

Reorganize file-based routes in TanStack Router for flexible nested routing.



In this lesson, we learn how to parametrize the loader for a nested route in TanStack Router.

We focus on a nested route like `/employees/$employeeId`, where the `$employeeId` is a **dynamic parameter**.

To fetch data for this route, we use a `loader` function that accesses the `$employeeId` parameter. This is achieved by using the params object available in the `loader` function, which contains the dynamic segments of the URL. We then use this parameter to call a function like `getEmployeeById`, which fetches specific employee details from an API.

We highlights that TanStack Router **automatically infers types** for these parameters, ensuring type safety for nested routes.

Parametrize Route Loader for Nested Route in Tanstack Router

Parametrize nested route loaders in TanStack Router using path parameters

In this lesson, we learn how to create nested routes and outlets in TanStack Router using file-based routing.

We start by creating a new `employees` directory and files to represent nested routes, such as `/employees/$employeeId`. The `$` symbol is used to denote dynamic parameters.

We then use the `<Link>` component from TanStack Router to create links to these nested routes, passing necessary parameters.

To render the nested content, we use the `<Outlet>` component (nested), which automatically renders child routes. This approach allows us to dynamically display stuff under a nested route.

All the time, the TanStack Router generator automatically updates the route tree based on file changes - our routing configuration remains consistent 🔥



Create Nested Route and Nested Outlets in Tanstack Router

Create nested routes and outlets in TanStack Router using file-based routing

Guy Bedford

Search Results