unvalley / ezno Goto Github PK

A JavaScript compiler and TypeScript checker written in Rust with a focus on static analysis and runtime performance.

What Ezno is

• A type checker for JavaScript usable through a CLI (with a LSP also in the works)
• A high level library that allows type checking to be added to other tools!
• Checks programs with guaranteed type safety (no runtime TypeErrors) (as long as definitions are sound)
• Types aimed at soundness and tracing for better static analysis
• A imperative type system that tracks and evaluates the side effects of functions and control flow structures. It is similar to an interpreter, but acts with types instead of values and does not run IO side effects etc
• A collection of experiments of types. Many are being worked out and are in the prototype stage. Some of the new behaviors benefit JavaScript specifically and others could be applied to other languages
• Written in Rust
• Fast and Small
• Open source! You can help build Ezno!
• A challenge to the status quo of type checking, optimisations and compilation through deeper static analysis beyond syntax analysis

What Ezno is not

• eNZo, the Z is in front of the N (pronounce as 'Fresno' without the 'fr') 😀
• Be on parity with TSC or 1:1, it has some different behaviors but should work in existing projects using TSC
• Faster as a means to serve large codebases. Cut out bloat and complex code first!
• Smarter as a means to allow more dynamic patterns. Keep things simple!
• A binary executable compiler. It takes in JavaScript (or a TypeScript or Ezno superset) and does similar processes to traditional compilers, but at the end emits JavaScript. However in the future it could generate a lower level format using its event (side-effect) representation

Read more about Ezno

• Introducing Ezno
• Ezno in '23
• A preview of the checker

This project is a workspace consisting of a few crates:

Crate	Lines Of Code	Contains
checker		Stores for types and contexts, type checking logic and optional synthesis over the parser AST
parser		AST definitions, logic for parsing, AST to string and visiting

Check out good first issues and comment on discussions! Feel free to ask questions on parts of the code of the checking implementation.

Read CONTRIBUTING.md for information about building and testing.