Go 1.21 introduces a new mechanism for building more modular and extensible WebAssembly applications. Previously, interacting with JavaScript from Go WASM required compiling all the code into a single, large WASM module. Now, developers can compile Go functions as individual WASM modules and dynamically import and export them using JavaScript's standard module loading system. This allows for creating smaller initial downloads, lazy-loading functionalities, and sharing Go-defined APIs with JavaScript, facilitating the development of more complex and dynamic web applications. This also enables developers to build extensions for existing WASM applications written in other languages, fostering a more interconnected and collaborative WASM ecosystem.
This Go blog post, titled "Extensible WASM Applications with Go," explores a novel approach to building WebAssembly (WASM) applications using Go that emphasizes extensibility and modularity. Traditional WASM development often involves compiling an entire application into a single WASM module. This approach, while functional, can lead to large file sizes and makes it difficult to update or extend the application without recompiling the entire codebase. This blog post introduces a new strategy where Go developers can compile smaller, independent WASM modules that can be dynamically loaded and integrated into a larger application at runtime.
The post details how this dynamic linking and loading mechanism works within the context of WASM and Go. It explains that this capability is enabled by the wasmexport prototype tool, a new command-line utility designed specifically for generating extensible WASM modules. wasmexport facilitates the process of exporting Go functions for use within a WASM environment and enables these functions to be called from other WASM modules or even JavaScript. This cross-module communication is a key aspect of achieving extensibility.
The blog post walks through a concrete example of building a simple drawing application. It demonstrates how to create separate WASM modules for different drawing shapes, like circles and triangles. Each shape module exports functions to draw the respective shape on a canvas. These modules are then loaded dynamically by a main WASM module, which acts as the orchestrator of the application. The main module can then call the drawing functions exposed by the individual shape modules, effectively combining them into a cohesive application.
The post emphasizes the benefits of this approach, highlighting the reduced initial download size as only the core application needs to be loaded initially. Additional modules, providing extra functionalities, can be downloaded and integrated on demand. This lazy-loading capability contributes to a more responsive user experience. The post further emphasizes the improved maintainability and update process, as modifications to individual modules do not necessitate a recompilation of the entire application. Only the updated module needs to be rebuilt and re-downloaded.
Finally, the post acknowledges that wasmexport is still a prototype and under active development. It encourages community feedback and contributions to further refine and solidify this promising approach to building extensible and modular WASM applications with Go. The overall message is that this new method offers a significant improvement over existing WASM development workflows, paving the way for more complex and dynamic web applications built with Go.
Summary of Comments ( 81 )
https://news.ycombinator.com/item?id=43045698
HN commenters generally expressed excitement about Go's new Wasm capabilities, particularly the ability to import and export functions, enabling more dynamic and extensible Wasm applications. Several highlighted the potential for creating plugins and modules with Go, simplifying development and deployment compared to current WebAssembly workflows. Some discussed the implications for server-side Wasm and potential performance benefits. A few users raised questions about garbage collection and memory management with this new functionality, and another thread explored comparisons to JavaScript's module system and the potential for better tooling around Wasm. Some expressed concerns about whether it's better to use Go or Rust for Wasm development, and there was an insightful dialogue comparing
wasmexportwith previous approaches.The Hacker News post "Extensible WASM Applications with Go" (https://news.ycombinator.com/item?id=43045698) has a moderate number of comments, discussing various aspects of using Go with WebAssembly (Wasm) and the implications of the
wasmexportfeature.Several commenters express enthusiasm for the potential of Wasm and Go's role in it. One user highlights the benefit of Go's relatively small runtime size compared to other languages, making it attractive for Wasm applications. This small runtime contributes to faster loading times and reduced resource consumption, which are crucial for web-based applications.
Another commenter notes the "plugin" architecture enabled by
wasmexport, where core Wasm modules can dynamically load and utilize extensions. They appreciate how this facilitates modularity and code reuse, envisioning scenarios where different teams can develop independent Wasm modules that seamlessly integrate with a central application. The commenter specifically mentions how this could be useful for developing extensions for software like image editors.A discussion emerges around the security implications of this dynamic loading capability. Some users raise concerns about the potential for malicious extensions to compromise the security of the core Wasm module. While acknowledging these risks, others point out that similar security concerns exist with traditional plugin systems and suggest that established security best practices can be applied to mitigate these risks in the Wasm context as well.
The conversation also touches on the broader ecosystem surrounding Wasm and its future. One commenter expresses hope that
wasmexportwill contribute to a thriving ecosystem of reusable Wasm modules. Another commenter draws a parallel betweenwasmexportand the dynamic linking features of operating systems, suggesting thatwasmexportcould pave the way for a more modular and flexible web.A few comments delve into the technical details of
wasmexport, discussing aspects such as interface definitions and the mechanisms for interaction between the core module and its extensions.Finally, some comments offer alternative perspectives. One user suggests exploring Web Workers as a potential solution for extensibility, arguing that this approach might offer certain advantages over
wasmexportin specific use cases. Another user questions the need for dynamic linking in the browser environment, suggesting that static linking might be sufficient for many applications.In summary, the comments on the Hacker News post reflect a generally positive outlook on the potential of
wasmexportto enhance the capabilities of Wasm applications developed with Go. While acknowledging potential security challenges, commenters express excitement about the possibilities for modularity, code reuse, and a richer Wasm ecosystem. The discussion also includes technical insights and alternative viewpoints, providing a balanced perspective on the topic.