Parze

Parze is a clean, efficient parser combinator written in Rust.

Example

A parser capable of parsing all valid Brainfuck code into an AST.

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 &- ']' => |ts| { Instr::Loop(ts) }
        ) *
    }
}

Features

All the usual parser combinator operations
Macro for simple rule and parser declaration
Support for recursive parser definitions
Custom error types - define your own!
Prioritised / merged failure for more useful errors
No dependencies - fast compilation!
no_std support

Why Parze?

Parze is largely a personal project. There is currently little reason to use it over a well-established existing parser combinator like pom.

Explicit Form

While Parze encourage 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.

let bf: Parser<_, _> = recursive(|bf| (
        sym('+').to(Instr::Add)
    .or(sym('-').to(Instr::Sub))
    .or(sym('<').to(Instr::Left))
    .or(sym('>').to(Instr::Right))
    .or(sym(',').to(Instr::In))
    .or(sym('.').to(Instr::Out))
    .or(sym('[').delimiter_for(bf).delimited_by(sym(']')).map(|ts| Instr::Loop(ts)))
).repeat(..));

License

Parze is distributed under either of:

Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)