ezno-parser 0.1.1

# Ezno's Parser

Contains "string to AST" parser, AST definitions, AST back to text/string form methods and hooks for traversing/visiting AST. Used in the Ezno checker.

![parser lines of code](https://projects.kaleidawave.workers.dev/project/ezno-parser/badge)
[![crates.io badge](https://img.shields.io/crates/v/ezno-parser?style=flat-square)](https://crates.io/crates/ezno-parser)
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This is more of an exercise project in getting better at writing Rust and doesn't offer too much over other great Rust based JS parsers such as [swc](https://github.com/swc-project/swc), [rome](https://github.com/rome/tools), [oxc](https://github.com/web-infra-dev/oxc) and [boa](https://github.com/boa-dev/boa).

## Goals

- Keep under 15k lines of code (excluding `/tests` and `/examples` folders)
- Easy to use (see `/tests` and `/examples` folders)
- Keep readable and maintainable
- **Designed for analysis and transformations**
    - See expression identifiers can be used to bind information to
    - Retain source positions for throwing errors
    - All AST should be visitable. Immutably to collect facts or mutable to transform/remove
- Optionally via configuration extend the ECMAscript language definition
    - TypeScript type annotations
        - Interfaces, enums and type alias statements
        - Parameter, return type and variable annotations
        - `satisfies` and `as` 😑
    - JSX support
        - Includes HTML comments, special handing of self closing tags from the specification
    - Others under `feature = "extras"` 👀

## Non-goals

- CSTs, close to source operations etc
    - Source with unbalanced parenthesis/brackets
- Increase code size or decrease readability for speed improvements
- Allow adding new syntax at runtime, that would require modifying the lexer at runtime adding new tokens

### Testing

> If in main root rather than this folder, add `-p ezno-parser` after `cargo run` to the following commands.

For testing whether the parser can lex a file

```shell
cargo run --example lex path/to/file.js
```

and parse

```shell
cargo run --example parse path/to/file.js
```

## Features

### Positions

All syntax has reference to where it was in the source using a [Span](https://docs.rs/ezno-parser/0.0.2/ezno_parser/struct.Span.html). This uses the [source-map](https://github.com/kaleidawave/source-map) crate, so it can generate source maps.

### "Cursors"

Allows holes in AST where a cursor exists. This allows for LSP to provide suggestions here while the whole source might not be valid.

### Visiting

[See example](https://github.com/kaleidawave/ezno/blob/main/parser/tests/visiting.rs)

### Generator

Easily generate AST nodes with data interpolation using the constant compiled quasi-quoted macro. [See example](https://github.com/kaleidawave/ezno/blob/main/parser/generator/examples/example.rs).

## Notable structures

- ASTNode, a trait that all AST should implement
- FunctionBase, a abstraction for functions
- Expression
- Statements
- Operators
- TSXToken
- TSXKeyword