pgn-reader
==========
A fast non-allocating reader for chess games in PGN notation, as a Rust library.
[](https://travis-ci.org/niklasf/rust-pgn-reader)
[](https://crates.io/crates/pgn-reader)
[](https://docs.rs/pgn-reader)
Introduction
------------
`Reader` parses games and calls methods of a user provided `Visitor`.
Implementing custom visitors allows for maximum flexibility:
* The reader itself does not allocate.
The visitor can decide if and how to represent games in memory.
* The reader does not validate move legality.
This allows implementing support for custom chess variants,
or delaying move validation.
* The visitor can signal to the reader that it does not care about a game or
variation.
Example
-------
A visitor that counts the number of syntactically valid moves in the
mainline of each game.
```rust
extern crate pgn_reader;
use pgn_reader::{Visitor, Skip, Reader, San};
struct MoveCounter {
moves: usize,
}
impl MoveCounter {
fn new() -> MoveCounter {
MoveCounter { moves: 0 }
}
}
impl<'pgn> Visitor<'pgn> for MoveCounter {
type Result = usize;
fn begin_game(&mut self) {
self.moves = 0;
}
fn san(&mut self, _san: San) {
self.moves += 1;
}
fn begin_variation(&mut self) -> Skip {
Skip(true) // stay in the mainline
}
fn end_game(&mut self, _game: &'pgn [u8]) -> Self::Result {
self.moves
}
}
fn main() {
let pgn = b"1. e4 e5 2. Nf3 (2. f4)
{ game paused due to bad weather }
2... Nf6 *";
let mut counter = MoveCounter::new();
let reader = Reader::new(&mut counter, pgn);
let moves: usize = reader.into_iter().sum();
assert_eq!(moves, 4);
}
```
Documentation
-------------
[Read the documentation](https://docs.rs/pgn-reader)
Benchmarks
----------
Run with [lichess_db_standard_rated_2014-07.pgn](https://database.lichess.org/standard/lichess_db_standard_rated_2014-07.pgn.bz2) (1,048,440 games, 1000 MB uncompressed) on an SSD, Intel i7-5500U CPU @ 2.40GHz.
examples/stats.rs | 4.0s | 249.4 MB/s
examples/validate.rs | 10.2s | 98.0 MB/s
examples/parallel_validate.rs | 4.5s | 222.2 MB/s
examples/lichess4545.rs | 1.6s | 625.0 MB/s
[`scoutfish make`](https://github.com/mcostalba/scoutfish) | 10.9s | 96.1 MB/s
`grep -F "[Event " -c` | 1.1s | 909.1 MB/s
License
-------
pgn-reader is licensed under the GPL-3.0 (or any later version at your option).
See the COPYING file for the full license text.