Introducing Walt for WebAssembly - Free Source Library

Walt: A JavaScript-like Syntax for WebAssembly

In the world of modern web development, the introduction of WebAssembly (Wasm) has significantly changed how developers approach performance-intensive tasks in the browser. WebAssembly enables developers to write code in languages like C, C++, and Rust and then compile it into a binary format that runs in the browser at near-native speed. However, the complexity of WebAssembly’s text format, often referred to as “Wasm text” or “wat,” has been a barrier for many developers. In response to this challenge, a new project called Walt was introduced. Walt is a JavaScript-like syntax for WebAssembly’s text format, designed to make the WebAssembly experience more approachable, readable, and maintainable.

The Need for a New Syntax

WebAssembly has gained widespread adoption because it offers near-native performance in web applications, making it possible to run computationally intensive code directly in the browser. However, writing WebAssembly code directly in the text format (WAT) can be cumbersome and unintuitive, especially for developers with a background in high-level languages like JavaScript, Python, or Ruby.

The WebAssembly text format is designed to be minimal and close to machine code, which makes it very efficient for browsers to parse and execute. However, this minimalism comes at the cost of readability and ease of use. Writing and maintaining WebAssembly code in WAT can be error-prone, particularly when dealing with large projects or more complex features.

This is where Walt comes into play. Walt is a high-level, human-readable alternative to the raw WebAssembly text format. It introduces a JavaScript-like syntax, which many web developers are already familiar with. The primary goal of Walt is to make WebAssembly more accessible by using familiar constructs, allowing developers to focus more on the logic of their applications and less on the intricacies of WebAssembly’s lower-level text format.

The Origins of Walt

Walt was introduced in 2017 by a developer known under the pseudonym BallerCat, with the intention of simplifying WebAssembly’s text format. The idea was to create a syntax that would be easier to read, write, and maintain, while still being closely tied to the WebAssembly execution model. Walt was not designed to replace WebAssembly but to offer an alternative representation that makes development more intuitive.

The project was made open-source, allowing developers to contribute and improve upon the original concept. Walt’s main selling point is its simplicity and familiarity for developers who are accustomed to JavaScript and similar programming languages.

Key Features of Walt

JavaScript-Like Syntax
Walt is designed to be familiar to developers who have worked with JavaScript. It uses many similar constructs and patterns, such as function and let, making it easier to write and understand WebAssembly code. For example, you can define a function in Walt in a manner similar to how you would in JavaScript:
```
javascript
func add(a, b) {
  return a + b;
}
```
Simplified Code Structure
Unlike the raw WebAssembly text format, which can be verbose and low-level, Walt uses a higher-level structure that is more abstract and easier to follow. This includes clearer definitions of variables, functions, and modules, and more natural-looking syntax.
Readable Function Signatures
Walt allows for easier-to-read function signatures. In the standard WebAssembly text format, defining a function’s parameters and return types can be somewhat cryptic. Walt abstracts these details in a way that makes the code more readable:
```
javascript
func add(i32, i32) -> i32 {
  return a + b;
}
```
Support for WebAssembly’s Core Features
While Walt is a higher-level abstraction, it still supports all of the core features of WebAssembly. This includes working with WebAssembly’s module system, memory management, and low-level operations like importing and exporting functions between the WebAssembly module and JavaScript. Walt’s goal is not to abstract away WebAssembly’s power, but to make it easier to work with.
Human-Readable Error Messages
Debugging WebAssembly code, especially when written in the raw WAT format, can be a frustrating experience. Walt aims to improve this by offering better error messages, which are often easier to understand and act upon. This feature is particularly useful for developers who are new to WebAssembly and may not be familiar with the intricacies of the raw text format.
Semantics for Readability
Walt introduces semantic indentation, which helps developers follow the logical flow of code more naturally. Indentation is not just about making the code look good; it also plays a crucial role in enhancing the understanding of how different sections of code interact with each other. This feature makes Walt closer to JavaScript in terms of style and readability.

Benefits of Using Walt

Improved Developer Productivity
By offering a syntax that closely resembles JavaScript, Walt reduces the learning curve for developers who are already familiar with web technologies. This allows for faster development and iteration on WebAssembly-based applications.
Increased Maintainability
Since Walt is more human-readable than raw WebAssembly text, it becomes easier to maintain WebAssembly code over time. Developers can more easily revisit and update their code, especially when collaborating in teams or working on large codebases.
Better Debugging and Error Handling
Walt’s error messages and syntax highlight help improve the debugging process. The more readable structure allows for quicker identification of issues, reducing the amount of time spent fixing bugs and troubleshooting problems.
Easy Transition from JavaScript
For developers already experienced with JavaScript, transitioning to Walt is a natural next step. Since the syntax is very similar to JavaScript, developers can more easily shift to working with WebAssembly without needing to learn a completely new language or format.

Walt vs. Raw WebAssembly Text Format (WAT)

To better understand the advantages of Walt, it’s useful to compare it to the raw WebAssembly text format (WAT), which is the default way of writing WebAssembly modules.

WAT Example

Here’s a simple example of adding two integers in the WAT format:

wat
(module
  (func $add (param $a i32) (param $b i32) (result i32)
    (i32.add
      (local.get $a)
      (local.get $b)
    )
  )
  (export "add" (func $add))
)

This code defines a function add that takes two integer parameters and returns their sum. While it’s functional, the syntax can be difficult for developers who are unfamiliar with the WebAssembly text format. The lack of high-level constructs makes it harder to quickly understand what the code is doing.

Walt Example

The same functionality written in Walt looks like this:

javascript
func add(i32, i32) -> i32 {
  return a + b;
}

In this example, the function is defined with a much more familiar JavaScript-like syntax. The parameters and return type are clearly specified, and the operation is expressed in a straightforward manner. It’s immediately obvious what the function does, even to someone with only a basic understanding of programming.

Getting Started with Walt

Walt is an open-source project, and developers can start using it by visiting its official website here. The website includes detailed documentation, examples, and instructions on how to install and use Walt. Additionally, the project is hosted on GitHub, where developers can report issues, contribute to the project, and stay updated with the latest developments.

The GitHub repository for Walt includes the source code and allows developers to contribute directly to the project. As of the latest updates, Walt has been actively maintained and has received contributions from the open-source community, which has helped to refine its syntax and functionality.

Conclusion

Walt represents an important step toward making WebAssembly more accessible to a broader range of developers. By providing a JavaScript-like syntax for WebAssembly’s text format, Walt significantly lowers the barrier to entry for WebAssembly development, allowing more developers to leverage the power of WebAssembly in their web applications. As the WebAssembly ecosystem continues to grow, tools like Walt will play an increasingly vital role in simplifying development workflows and improving the overall developer experience.

For developers already working with WebAssembly, or those considering it for performance-critical parts of their web applications, Walt offers a promising and highly productive alternative to the traditional WAT format. Its familiarity, readability, and ease of use make it a valuable tool for anyone looking to write WebAssembly code more efficiently and with greater clarity.