Files
ghostty/example/zig-vt-stream/src/main.zig
Mitchell Hashimoto 2044e5030f terminal: make stream processing infallible
The terminal.Stream next/nextSlice functions can now no longer fail.
All prior failure modes were fully isolated in the handler `vt`
callbacks. As such, vt callbacks are now required to not return an error
and handle their own errors somehow.

Allowing streams to be fallible before was an incorrect design. It
caused problematic scenarios like in `nextSlice` early terminating
processing due to handler errors. This should not be possible.

There is no safe way to bubble up vt errors through the stream because
if nextSlice is called and multiple errors are returned, we can't
coalesce them. We could modify that to return a partial result but its
just more work for stream that is unnecessary. The handler can do all of
this.

This work was discovered due to cleanups to prepare for more C APIs.
Less errors make C APIs easier to implement! And, it helps clean up our
Zig, too.
2026-03-13 13:56:14 -07:00

41 lines
1.2 KiB
Zig

const std = @import("std");
const ghostty_vt = @import("ghostty-vt");
pub fn main() !void {
var gpa: std.heap.DebugAllocator(.{}) = .init;
defer _ = gpa.deinit();
const alloc = gpa.allocator();
var t: ghostty_vt.Terminal = try .init(alloc, .{ .cols = 80, .rows = 24 });
defer t.deinit(alloc);
// Create a read-only VT stream for parsing terminal sequences
var stream = t.vtStream();
defer stream.deinit();
// Basic text with newline
stream.nextSlice("Hello, World!\r\n");
// ANSI color codes: ESC[1;32m = bold green, ESC[0m = reset
stream.nextSlice("\x1b[1;32mGreen Text\x1b[0m\r\n");
// Cursor positioning: ESC[1;1H = move to row 1, column 1
stream.nextSlice("\x1b[1;1HTop-left corner\r\n");
// Cursor movement: ESC[5B = move down 5 lines
stream.nextSlice("\x1b[5B");
stream.nextSlice("Moved down!\r\n");
// Erase line: ESC[2K = clear entire line
stream.nextSlice("\x1b[2K");
stream.nextSlice("New content\r\n");
// Multiple lines
stream.nextSlice("Line A\r\nLine B\r\nLine C\r\n");
// Get the final terminal state as a plain string
const str = try t.plainString(alloc);
defer alloc.free(str);
std.debug.print("{s}\n", .{str});
}