vtty

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

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");

// With the `simd-transcode` feature enabled, opt into SIMD scanning,
// validation and UTF-8→UTF-32 transcode:
let mut parser = Parser::with_simd();
parser.advance(&mut screen, b"\x1b[1;31mhello\x1b[0m");

Also available: Event/Recording (owned enum API), State (byte-cursor sink with line/cursor geometry), Reply (query reply builder), and ColorId, SgrFlags, TermFlags, KittyFlags, MouseButton, Charset, Cap.

Design

• Panic-free — #![forbid(unsafe_code)]; malformed PTY input never crashes.
• Zero-allocation hot path — one print_bytes per ASCII run, one print_codepoints per non-ASCII run; CSI/OSC/DCS state is inline.
• no_std by default — optional simd (scanning + validation) and simd-transcode (UTF-8→UTF-32) features, enabled per parser.
• W3C-correct UTF-8 — maximal-subpart substitution; 8-bit clean (DEC “anywhere”).

Test

cargo test -p vtty
cargo test -p vtty --test vt_differential -- --nocapture  # parity vs vte