vampirc-uci

Vampirc UCI is a Universal Chess Interface (UCI) protocol parser and serializer.

The UCI protocol is a way for a chess engine to communicate with a chessboard GUI, such as Scid vs. PC.

The Vampirc Project is a chess engine and chess library suite, written in Rust. It is named for the Slovenian grandmaster Vasja Pirc, and, I guess, vampires? I dunno.

Vampirc UCI uses the PEST parser to parse the UCI messages. If you want to build your own abstractions of the protocol, the corresponding PEG grammar is available here.

Installing the library

To use the crate, declare a dependency on it in your Cargo.toml file:

[dependencies]
vampirc-uci = "0.8"

Then reference the vampirc_uci crate in your crate root:

extern crate vampirc_uci;

Usage

1. Import either the parse(..) method or the parse_strict(..) method. The difference between them is that parse_strict(..) will return a pest::error::Error if any of the input is unrecognized or violates the rules of the PEG grammar, whereas parse will simply ignore any such input. The latter is the approach recommended by the protocol specification.

use vampirc_uci::parse;

2. Some other useful imports (for message representation):

use vampirc_uci::{UciMessage, MessageList, UciTimeControl, Serializable};

3. Parse some input:

let messages: MessageList = parse("uci\nposition startpos moves e2e4 e7e5\ngo ponder\n");

4. Do something with the parsed messages:

for m in messages {
    match m {
        UciMessage::Uci => {
            // Initialize the UCI mode of the chess engine.
        }
        UciMessage::Position { startpos, fen, moves } => {
            // Set up the starting position in the engine and play the moves e2-e4 and e7-e5
        }
        UciMessage::Go { time_control, search_control } {
            if let Some(tc) = time_control {
                match tc {
                    UciTimeControl::Ponder => {
                        // Put the engine into ponder mode ("think" on opponent's time)
                    }
                    _ => {...}
                }
            }
        }
        _ => {...}
    }
}

5. Outputting the messages

    let message = UciMessage::Option(UciOptionConfig::Spin {
                name: "Selectivity".to_string(),
                default: Some(2),
                min: Some(0),
                max: Some(4),
            });
    
    println!(message); // Outputs "option name Selectivity type spin default 2 min 0 max 4"

API

The full API documentation is available at docs.rs.

New in 0.8.3

• Added the UciMessage::info_string() utility function.
• Allowed the empty go command (see Parser cannot parse "go\n").

New in 0.8.2

• Added ByteVecUciMessage as a UciMessage wrapper that keeps the serialized form of the message in the struct as a byte Vector. Useful if you need to serialize the same message multiple types or support AsRef<[u8]> trait for funnelling the messages into a futures::Sink or something.
• Modifications for integration with async async-std based vampirc-io.

New in 0.8.1

• Added parse_with_unknown() method that instead of ignoring unknown messages (like parse) or throwing an error (like parse_strict) returns them as a UciMessage::Unknown variant.

New in 0.8.0

• Support for parsing of the info message, with the UciAttributeInfo enum representing all 17 types of messages described by the UCI documentation, as well as any other info message via the Any variant.

New in 0.7.5

• Support for parsing of the option message.
• Proper support for <empty> strings in option and setoption.

vampirc-io

This crate goes together well with the vampirc-io crate, a library for non-blocking communication over standard input and output (which is how UCI communication is usually conducted), based on the async-std framework.

Limitations and 1.0

The library is functionally complete – it supports the parsing and serialization to string of all the messages described by the UCI specification. Before the 1.0 version can be released, though, this library needs to be battle tested more, especially in the upcoming Vampirc chess engine.

Furthermore, as I am fairly new to Rust, I want to make sure the implementation of this protocol parser is Rust-idiomatic before releasing 1.0. For this reason, the API should not be considered completely stable until 1.0 is released.

Additionally, some performance testing would also not go amiss.

Supported engine-bound messages (100%)

• uci
• debug
• isready
• register
• position
• setoption
• ucinewgame
• stop
• ponderhit
• quit
• go

Supported GUI-bound messages (100%)

• id
• uciok
• readyok
• bestmove
• copyprotection
• registration
• option
• info