vtty

Zero-allocation, panic-free DEC VT500 terminal parser with UTF-8 decoding and no_std support

Crates

crate	purpose
vtty	the parser (re-exports vtty_core)
vtty_core	terminal model types + Perform
vtty_codec	no_std binary Encode/Decode codec for vtty_core
vtty_width	display cell width + emoji sequences
vtty_grapheme	UAX #29 grapheme cluster segmentation
vtty_status	OSC 7501 Program Status Protocol
vtty_screen	cell-grid terminal screen
vtty_ffi	raw C ABI
vtty_bench	throughput benchmarks

Features

• Safety — #![forbid(unsafe_code)], no unwrap/expect/panic.
• Zero-allocation — bulk print_bytes / print_codepoints.
• no_std — optional simd / simd-transcode features.
• UTF-8 — maximal-subpart substitution; 8-bit C1 controls.
• Serialization — compact, no_std, zero-allocation Encode/Decode codec (vtty_codec) for events, replies, and terminal state.

Install

cargo add vtty

Usage

use vtty::{Parser, Perform};

struct Screen;

impl Perform for Screen {
    fn print_bytes(&mut self, s: &[u8]) { /* printable ASCII run */ }
    fn print(&mut self, c: char) { /* non-ASCII code point */ }
    fn execute(&mut self, b: u8) { /* \n \t \x1b … */ }
    fn csi_dispatch(&mut self, params: &[i32], sep: u16, intermediates: &[u8], final_byte: u8) {
        /* CSI Ps ; Ps final */
    }
    fn osc_dispatch(&mut self, params: &[&[u8]], bell: bool) { /* OSC */ }
}

let mut parser = Parser::new();
parser.advance(&mut screen, b"\x1b[1;31mhello\x1b[0m");

Serialization

Owned events, replies and terminal state round-trip through a compact, no_std binary codec:

use vtty_codec::{decode_from_slice, encode_to_vec};
use vtty::{Event, Parser};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Owned events encode/decode as data:
    let mut parser = Parser::new();
    let events = parser.parse_events(b"\x1b[1;31mhi");

    let bytes = encode_to_vec(&events)?;
    let restored = decode_from_slice::<Vec<Event>>(&bytes)?;

    assert_eq!(events, restored);
    Ok(())
}

Benchmarks

Throughput vs vte/vt100/vtparse/rio-vt — see crates/vtty_bench for the full table.

Testing

cargo test --workspace
cargo test -p vtty --test vt_differential -- --nocapture      # parity vs vte
cargo test -p vtty --test vt_differential_rio -- --nocapture  # parity vs rio-vt

License

Licensed under either of Apache-2.0 or MIT at your option.