If this ships, it will change javascript forever

Summary

The transcript discusses the introduction of signals in JavaScript through a TC39 proposal, highlighting its potential for improving data flow and reactivity in applications. It emphasizes the collaborative effort of industry experts and the proposal's current stage, encouraging community involvement and feedback for further development and refinement.

Takeaways

• 🚀 Introduction of a TC39 proposal for signals in JavaScript, aiming to standardize a way to handle reactive state and computations.
• 🌟 The proposal is at an early stage (Stage 0), with significant industry collaboration and input from major contributors in the field.
• 🔗 The proposal includes detailed documentation such as background, motivations, design goals, FAQs, and proposed APIs for both state and computed signals.
• 🛠️ A spec-compliant polyfill is available for experimentation and feedback, allowing developers to start using the signal features today.
• 📈 The signal pattern is inspired by performance optimizations in frameworks like Svelte and the solid.js library, which prioritize efficient data flow and reactivity.
• 🔄 Signals enable one-way data flow, making it easier to debug and reason about application state by modeling cells of state and derived computations.
• 📊 The concept of 'clean' and 'dirty' signals allows for efficient tracking of changes and updates, only recomputing values when necessary.
• 🎯 The proposal aims to provide primitives for library authors to build their own effects, rather than prescribing a one-size-fits-all effect API.
• 🔧 The use of the `signal.subtle` namespace for APIs that should be used with care, primarily by framework authors and library maintainers.
• 🔄 The potential for increased interoperability and smaller bundle sizes if the standard is adopted across different frameworks and libraries.
• 📢 A call to action for the community to get involved in the development of the proposal, including testing, feedback, and prototyping.

Q & A

What is the main topic of the video?

The main topic of the video is the introduction of a TC39 proposal for signals in JavaScript, which aims to enable one-way data flow and improve the debugging and understanding of application flows.

What is the significance of the Solid framework mentioned in the video?

Solid is mentioned as a framework that is signals-based instead of reaction-based, which contributes to its high performance. It is often compared to React but is noted for its signals approach, which is a key focus of the video.

Who are some of the notable people involved in the signals proposal?

Notable people involved in the signals proposal include Daniel Erenberg from Bloomberg, Dominic Gannaway who is an original React core team member, Michael West from Meta, and Ben Les, the creator of RxJS.

What is the current status of the signals proposal?

The signals proposal is currently in Stage 0, which means it is in the very early stages of discussion and development. It has not yet been formally considered by TC39.

How does the signal data type work?

A signal is a data type that models cells of state and computations derived from other state. It enables one-way data flow and can be either a source of state (signal.state) or a computed value (signal.computed). Changes in the source signal propagate to dependent computed signals.

What is the 'push then pull' model mentioned in the video?

The 'push then pull' model refers to the way signals update. When a change occurs in a signal, the change is pushed through the graph to dependent signals. However, recomputation is delayed until a specific signal's value is explicitly pulled or accessed.

What are some advantages of using signals?

Some advantages of using signals include automatic memoization, avoidance of unnecessary recomputation, the ability to be notified when signals become dirty, and the option to choose how to react to these changes.

How does the video suggest library authors could use the signal proposal?

Library authors could integrate the signal proposal by updating their libraries to use signal.state and signal.computed internally. They could also build their own effects using the primitives provided in the signal.subtle namespace.

What is the role of the signal.subtle namespace?

The signal.subtle namespace provides APIs for library and framework authors to build their own effects and handle advanced use cases. It includes utilities like signal.subtle.watcher for tracking signal changes and signal.subtle.untrack for executing code without tracking signal access.

What is the next step for the signals proposal?

The next step for the signals proposal is to reach Stage 1 in the TC39 process, which means the proposal will be formally considered by the group. The proposal will continue to evolve based on feedback from TC39 meetings and contributions from the community.

How can interested individuals get involved with the signals proposal?

Individuals can get involved by checking the link provided in the video description, which leads to a section on how to contribute to the proposal. Contributions can range from testing, reporting on other signal implementations, to providing feedback and ideas.