[](https://crates.io/crates/parze)
[](https://docs.rs/parze)
# Parze
Parze is a clean, efficient parser combinator written in Rust.
## Example
A parser capable of parsing all valid Brainfuck code into an AST.
```rust
use parze::prelude::*;
#[derive(Clone, Debug, PartialEq)]
enum Instr { Add, Sub, Left, Right, In, Out, Loop(Vec<Instr>) }
parsers! {
bf = {
( '+' -> { Instr::Add }
| '-' -> { Instr::Sub }
| '<' -> { Instr::Left }
| '>' -> { Instr::Right }
| ',' -> { Instr::In }
| '.' -> { Instr::Out }
| '[' -& bf &- ']' => { |i| Instr::Loop(i) }
) *
}
}
```
## Features
- [x] All the usual parser combinator operations
- [x] Macro for simple rule and parser declaration
- [x] Support for recursive parser definitions
- [x] Custom error types - define your own!
- [x] Prioritised / merged failure for more useful errors
- [x] No dependencies - fast compilation!
- [x] `no_std` support
## Why Parze?
Parze is fast and lightweight, acting as a bare-bones framework upon which more verbose and interesting parsers can be constructed (see the `custom_error` example).
## Nightly
Parze's declaration macro currently requires a nightly Rust compiler to work.
You may use the explicit declaration form (as shown below) with stable by disabling the `nightly` feature, however.
This can be done like so in your `Cargo.toml`:
```
[dependencies.parze]
version = "x.y.z"
default-features = false
```
## Performance
Here are the results of a JSON parsing test when compared with [`pom`](https://github.com/J-F-Liu/pom). More performance metrics to come later.
```
test parze ... bench: 3,696,323 ns/iter (+/- 358,597)
test pom ... bench: 18,538,775 ns/iter (+/- 1,149,589)
```
## Explicit Form
While Parze encourages use of macros for much of its declarative notation, it is possible (and often useful) to make use of the more explicit rust-y notation.
Here is the Brainfuck parser given above, declared in explicit form.
```rust