Joe Savona
79167dcb38
First a quick fix: if we have a known type for the lvalue of CreateFrom, we can drop the effect. This is a bit awkward generally because the types and abstract values overlap a bit, and i'd prefer to only look at types during one phase. So maybe move all the type-checking to where we generate effects, and then after that applyEffect() doesn't have to consider types. The larger fix is for InferMutationAliasingRanges. When processing a mutation we have to walk the graph in both forward and backwards directions. Consider `alias a -> b, mutate(b)`. We have to walk back the alias chain from b to a, and mark a as mutated too. But for `alias a -> b, mutate(a)`, we also have to mark b as mutated — walking forwards along the alias chain. But phis are a bit different. You can have a mutation of one of the phi operands, such that you have `a, b -> phi c, mutate(a)`. Here, we do need to mark c as mutated, but we should not walk back to b — it's a different operand! a and b don't alias together. There are now about 150 fixtures failing, but they're in a few categories and all of them are addressable: * Infinite loops. `applyEffect()` creates new un-memoized effect values which means that any input with a backedge (loop) will spin until my infinite loop detection throws. This is somewhat tedious to address but it's a pragmatic concern and not a flaw in the model. I also need to convince myself that the approach in InferMutationAliasingRanges is safe for loops, but first i have to get inputs w loops to even reach that phase. * LoadContext/StoreContext - i currently treat these too similarly to regular load/store, ie assuming the mutations happen in order. One idea is to treat LoadContext as a mutate instead of an alias, just to make sure all instances get grouped together. * InvalidReact detection. We already synthesize MutateFrozen/MutateGlobal effects but we don't throw these as errors yet. This is probably the largest category of failing tests, which means overall this is actually "pretty close" (so, 50% of the way there). [ghstack-poisoned]
React · 
React is a JavaScript library for building user interfaces.
- Declarative: React makes it painless to create interactive UIs. Design simple views for each state in your application, and React will efficiently update and render just the right components when your data changes. Declarative views make your code more predictable, simpler to understand, and easier to debug.
- Component-Based: Build encapsulated components that manage their own state, then compose them to make complex UIs. Since component logic is written in JavaScript instead of templates, you can easily pass rich data through your app and keep the state out of the DOM.
- Learn Once, Write Anywhere: We don't make assumptions about the rest of your technology stack, so you can develop new features in React without rewriting existing code. React can also render on the server using Node and power mobile apps using React Native.
Learn how to use React in your project.
Installation
React has been designed for gradual adoption from the start, and you can use as little or as much React as you need:
- Use Quick Start to get a taste of React.
- Add React to an Existing Project to use as little or as much React as you need.
- Create a New React App if you're looking for a powerful JavaScript toolchain.
Documentation
You can find the React documentation on the website.
Check out the Getting Started page for a quick overview.
The documentation is divided into several sections:
- Quick Start
- Tutorial
- Thinking in React
- Installation
- Describing the UI
- Adding Interactivity
- Managing State
- Advanced Guides
- API Reference
- Where to Get Support
- Contributing Guide
You can improve it by sending pull requests to this repository.
Examples
We have several examples on the website. Here is the first one to get you started:
import { createRoot } from 'react-dom/client';
function HelloMessage({ name }) {
return <div>Hello {name}</div>;
}
const root = createRoot(document.getElementById('container'));
root.render(<HelloMessage name="Taylor" />);
This example will render "Hello Taylor" into a container on the page.
You'll notice that we used an HTML-like syntax; we call it JSX. JSX is not required to use React, but it makes code more readable, and writing it feels like writing HTML.
Contributing
The main purpose of this repository is to continue evolving React core, making it faster and easier to use. Development of React happens in the open on GitHub, and we are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving React.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our contributing guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React.
Good First Issues
To help you get your feet wet and get you familiar with our contribution process, we have a list of good first issues that contain bugs that have a relatively limited scope. This is a great place to get started.
License
React is MIT licensed.