# token-parser
Parse texts into Rust data structures via a small intermediate format of nested lists and symbols (`Unit`).
`token-parser` is a backend for parsers: instead of writing a full parser for each format, you tokenize once into `Unit`s, and any type implementing `Parsable` can be extracted. Implementations are provided for primitives, `String`, `Box<str>`, `PathBuf`, `Vec<T>`, `Box<T>`, `Rc<T>`, `Arc<T>`, and (via the `derive` feature) for your own structs and enums.
## Example
```rust
use token_parser::{Parser, Span, Unit};
let units = [Unit::Symbol("hello".into(), Span::default())];
let mut parser = Parser::new(units);
let value: String = parser.parse_next(&()).unwrap();
assert_eq!(value, "hello");
```
For lists:
```rust
let words = [
Unit::Symbol("a".into(), Span::default()),
Unit::Symbol("b".into(), Span::default()),
];
let mut parser = Parser::new([Unit::Parser(Parser::new(words))]);
let value: Vec<String> = parser.parse_next(&()).unwrap();
assert_eq!(value, vec!["a".to_string(), "b".into()]);
```
## Features
- `derive` — enables `#[derive(Parsable)]` via `token-parser-derive` for structs and enums.
- `radix-parsing` — number parsing with configurable radix via the `Context` trait.
## Errors
`Error` carries an `ErrorKind` (`NotEnoughElements`, `TooManyElements`, `ListNotAllowed`, `SymbolNotAllowed`, `StringParsing`, `InvalidElement`) and an optional `Span`.
## License
MIT OR Apache-2.0