screen-clone was 2.6x slower than Zig. The main cost was in
PageList::clone_range: it created a throwaway page, recycled it into the
pool and Page::reinit then memset the entire page again, faulting in
every cell. Untouched pages now go to a clean_pool that create_node
reuses without re-zeroing. Page::init allocates cells with
bytemuck::allocation::try_zeroed_vec (Cell derives Zeroable), getting
lazily-zeroed memory from the allocator without unsafe code, and
clone_partial_row_from bulk-copies plain-cell runs in rows with managed
memory. screen-clone clone: 78 ms -> ~28 ms (Zig ~27.8 ms).
osc::Parser::next_slice appends payload bytes in bulk while behaving
exactly like per-byte next() (2048 limit, overflow), verified by a
property test; the osc-parser bench uses it (54.5 -> ~32 ms, Zig ~28).
Still slower: screen-clone render (~2.4x), dominated by per-row style
vectors in RenderState::update.
Test Plan:
- cargo test --workspace (no failures)
- ghostty-bench +screen-clone / +osc-parser with --profile production
Cleanup pass over items collected in docs/rewrite/INTEGRATION_TODO.md:
- OSC 133 printf-q / percent decoders live once in
ghostty_vt::string_encoding; ghostty-os re-exports them.
- CursorStyle and clipboard codepoint map entries have one definition
(ghostty-terminal); ghostty-config now depends on ghostty-terminal.
- ActionKey::docs() trailing blank lines fixed at the source; cli's
workaround removed (+list-actions --docs still byte-identical).
- x11_color exposes names in original case; cli no longer re-parses
rgb.txt.
- One cgroup scope wait loop (ghostty_os::cgroup::wait_for_scope).
- Flatpak passwd lookup implemented in ghostty-os via a local pty.
- +version shows the rustc version captured at build time.
Resources: dev builds find <workspace>/resources automatically (keeping
Ghostty's sentinel-file detection and GHOSTTY_RESOURCES_DIR);
scripts/gen-terminfo.sh (just terminfo) regenerates the compiled
terminfo; `just install [PREFIX]` installs binary, share/ghostty,
terminfo, desktop/D-Bus/systemd/metainfo files and icons.
Test Plan:
- cargo test for vt, os, config, input, cli
- diff `+list-keybinds`, `+list-actions --docs`, `+show-config --default`
against /usr/bin/ghostty
Adds crates/ghostty-bench, a port of ZIG/src/benchmark and src/synthetic:
the ghostty-bench binary (terminal-stream, terminal-parser,
codepoint-width, grapheme-break, is-symbol, osc-parser, screen-clone
with Zig's CLI) and ghostty-synthetic data generators (+ascii, +utf8,
+osc, plus a Rust-only +sgr mode).
Measured against Ghostty's own ghostty-bench built with Zig 0.15.2
(ReleaseFast) vs --profile production, the hot paths were optimized
without behaviour changes:
- Terminal::print single-lookup fast path for width-1 chars mid-line
- page grapheme allocator: bitmap first-fit instead of a linear scan
(was 38% of utf8 stream time; randomized equivalence test added)
- plain cells skip per-cell work in clear_cells and row cloning
- ASCII fast path + strict hand-written UTF-8 decoder (exhaustive
equivalence test against std)
- parser/OSC parser split into inlined fast and state-change paths
- RenderState allocates grapheme vectors only for grapheme rows
- Page::assert_integrity no-op stub so the production profile builds
terminal-stream is now at parity (ascii 1.08x, utf8 0.97x, SGR 1.04x of
Zig's time). Still slower: screen-clone (~2.6x, zero-filling fresh
cell Vecs vs Zig's lazily-zeroed mmap), osc-parser (1.9x), and the raw
parser on SGR data (1.5x). Full table in docs/rewrite/notes/perf-P1.md.
Test Plan:
- cargo test --workspace (no failures)
- cargo run --profile production -p ghostty-bench -- +terminal-stream
--data=<file> and compare with Zig's ghostty-bench
Makes the resources directory self-contained like Ghostty's share/ghostty:
- themes/: the 463 iTerm2-Color-Schemes themes Ghostty 1.3.1 ships
(release 20260216-151611-fc73ce3), with the upstream MIT license.
- terminfo/: xterm-ghostty compiled with `tic -x` from the terminfo
source generated by ghostty-termio; `infocmp -x` is identical to the
installed Ghostty's entry.
The generator script and resources-dir discovery changes follow in a
separate commit.
Test Plan:
- TERMINFO=resources/terminfo infocmp -x xterm-ghostty
This is the integration step that turns the ported crates into a working
terminal: `cargo run` now opens a GTK window running the user's shell.
ghostty-core ports App.zig, Surface.zig (split into keyboard, mouse,
binding, clipboard and config submodules), surface_mouse.zig and
global.zig, and implements the runtime traits. perform_binding_action
handles every binding action.
Cross-crate integration:
- The core<->runtime traits (CoreApp, CoreSurface, RtApp, RtSurface,
Waker) move from apprt-gtk into ghostty_apprt::runtime_api so the core
stays runtime-agnostic; Scrollbar/RendererHealth stand-ins are replaced
by the real terminal/renderer types.
- termio now uses ghostty_renderer::state::{State, SharedState}; the
renderer calls kitty_update; image-storage-limit is applied at init
and on config change.
- The search thread locks the terminal through a TerminalLock trait so
it can share the render state mutex; termio's Wakeup gained a hook to
wake the renderer thread.
- apprt-gtk: GL proc addresses are resolved through libepoxy's
epoxy_glFoo pointer variables (plain glFoo symbols resolved to null),
default DPI fixed to 96, libadwaita version read without GTK init so
--version works headless.
The root binary dispatches +actions to ghostty-cli (list-fonts,
show-face and new-window are now wired) and otherwise runs the GTK app
with the real core.
Verified at runtime on Wayland and X11: shell prompt and colored output
render, child exit closes the window cleanly. Not yet verified: keyboard
and mouse input, clipboard, IME, tabs and splits (no key injection was
possible in this environment). GHOSTTY_DEBUG_SCREENSHOT=<png> dumps the
renderer's last frame for headless checks.
Test Plan:
- cargo test --workspace (2890 passed)
- cargo clippy --workspace --all-targets -- -D warnings
- GSETTINGS_BACKEND=memory GHOSTTY_RESOURCES_DIR=/usr/share/ghostty \
cargo run
Ports renderer/{generic,cell,row,link,State,Overlay,image,Thread}.zig:
- generic.rs builds GPU cell buffers from terminal RenderState each
frame: backgrounds, shaped text runs with glyph atlases and nerd font
constraints, all cursor styles, decorations via sprites, selection and
search colors, min-contrast, bold/faint/blink handling, preedit,
padding extension, background image, custom shader uniforms, link
hover underlines, scrollbar and health reporting.
- The renderer thread updates CPU-side state only and asks the host to
redraw; the app runtime calls draw_frame from the GLArea render signal
(the GL context lives on the GTK thread, as in Ghostty).
- ghostty_renderer::state::{State, SharedState} is the canonical shared
renderer state (termio's interim copy will switch to it).
Deviations: overlay uses a direct RGBA rasterizer instead of z2d; bg
images decode with png/jpeg-decoder instead of wuffs; zero-length link
matches advance by one char (Zig would loop forever).
Kitty image rendering is implemented in image::State but not yet called
from generic::update_kitty (raced with the terminal-side wiring).
Test Plan:
- cargo test -p ghostty-renderer (69 unit + 9 headless EGL tests that
render a Terminal through the full pipeline and check pixels)
Ports the remainder of ZIG/src/termio: Options, backend, message,
mailbox, Termio, Thread, Exec and stream_handler.
Threading model (replacing libxev): the IO thread owns Termio and runs a
single poll(2) loop over the mailbox eventfd, a stop eventfd, the child
pidfd and pty POLLOUT, driving Ghostty's timers (25 ms resize
coalescing, 1 s synchronized-output, 15 ms selection scroll, 200 ms
termios polling). A separate pty read thread locks the shared renderer
state and feeds the terminal. Renderer and surface interaction go
through RendererMailbox/SurfaceMailbox traits.
The stream handler answers all queries (DA, DSR, XTVERSION, DECRQM,
OSC color queries, XTGETTCAP, DECRQSS, ...) and forwards titles, pwd,
OSC 52, notifications, progress and bell as surface messages. Zig
unlocks the renderer mutex when a mailbox is full; here overflow goes to
an ordered outbox flushed after the locks drop.
IO1's local stand-ins are replaced with the real config types.
Open: RendererState lives in termio for now (renderer State.zig is
being ported); kitty graphics replies and tmux viewer are not hooked up;
wait-after-command lives in Surface (core); Flatpak stop path needs a
ghostty-os change.
Test Plan:
- cargo test -p ghostty-termio (102 unit + 21 end-to-end tests on a
real pty, incl. backpressure, DA1 replies, resize coalescing, exits)
Integration pass over the terminal core (Codex/gpt-6-astra, reviewed):
- Screen now owns the real kitty ImageStorage; new/reset/teardown,
erase-display deletes and alternate-screen limit inheritance hook in
where Zig does, and Terminal implements ExecTerminal so kitty APC
commands execute against it. Exec tests use a real Terminal.
- The PageList gains the APIs Screen/Terminal needed (pin iterators,
cross-page row/partial-row clone, string allocator probing, dedup
before allocating hyperlinks, Top viewport fixup after erase, append_
grapheme no longer marking rows dirty), and the Screen/Terminal
workarounds for their absence are removed so the code mirrors Zig.
Public signatures are unchanged; downstream crates build as before.
Test Plan:
- cargo test -p ghostty-terminal (1252 passed, 0 ignored)
- cargo clippy -p ghostty-terminal --all-targets -- -D warnings
Ports ZIG/src/apprt/gtk into ghostty-apprt-gtk: every GObject class
(application, window, tab, split tree, surface + scrolled window,
child-exited banner, search/key-state/resize overlays, command palette,
global shortcuts, all dialogs, config wrapper) as glib subclasses with
the same GType names, properties, signals and template children; GDK
key translation; X11 and Wayland window-protocol helpers (blur, CSD,
quick terminal via gtk4-layer-shell); single-instance D-Bus IPC;
gsettings; cgroup scope creation.
build.rs compiles Ghostty's blueprints with blueprint-compiler and
bundles UI, CSS and icons into a gresource, as Ghostty's build does.
The core is not ported yet, so the crate defines the boundary it needs
in src/core.rs (CoreApp, CoreSurface, RtApp, RtSurface, Waker); the
spec is in docs/rewrite/notes/ghostty-apprt-gtk.md. ghostty-core will
implement these traits (the crate no longer depends on core to avoid a
cycle). examples/demo.rs runs the app with a dummy core that clears the
GLArea; it launches on Wayland without GTK criticals.
Stubs/open items: toggle_visibility, float_window, secure_input and
close_all_windows return false; inspector is a no-op; X11/Wayland
protocol code is untested against real compositors; gtk4-rs doesn't
expose the GLArea framebuffer id, so the renderer must query it.
Also registers ghostty-apprt and ghostty-cli in workspace.dependencies.
Test Plan:
- cargo test -p ghostty-apprt-gtk (36 tests)
- DEMO_QUIT_AFTER_MS=3000 cargo run -p ghostty-apprt-gtk --example demo
Ports ZIG/src/terminal/kitty/graphics_*.zig:
- image loading for direct, file, temp-file and shared-memory
transmissions (rustix::shm, no unsafe), chunking, zlib and PNG decode
- image storage with placements (incl. virtual) tracked by PageList pins,
all delete modes, byte-limit eviction and dirty tracking
- unicode placeholder decoding and placement iteration
- command execution, generic over an ExecTerminal trait
Deviations: storage methods take the PageList explicitly; evicted or
replaced placements now release their tracked pins (Zig leaks them);
file transmissions with S= truncate per the kitty spec. Zig quirks kept
for parity: delete-range matches all placements, eviction stops only
after freeing strictly more than requested, set_limit(0) resets.
Not yet wired: Screen still holds the KittyImages placeholder, so
Terminal does not implement ExecTerminal; integration steps are in
docs/rewrite/notes/ghostty-terminal-kitty.md.
Test Plan:
- cargo test -p ghostty-terminal (66 kitty tests; all Zig tests ported)
search/: sliding-window matcher over pages, active-area, page list,
viewport and screen searches, and the background search thread (std
thread + crossbeam-channel mailbox, 24 ms refresh, terminal behind
Arc<Mutex<_>>). Searches take &mut Screen explicitly; ScreenSearch::deinit
must be called to untrack pins. The sliding window uses a VecDeque
instead of CircBuf (same results; two layout-only assertions dropped).
tmux/: layout parsing, output formatting and the control-mode viewer
state machine, reusing ghostty_vt::tmux::control for parsing. The viewer
is not wired into termio yet; steps are in the notes.
The renderer must set terminal.flags.search_viewport_dirty for the
search thread to re-search the viewport.
Test Plan:
- cargo test -p ghostty-terminal --lib search (54; 51/53 Zig tests,
2 allocator-failure tests skipped)
- cargo test -p ghostty-terminal --lib tmux (96; all Zig tests)
- render.rs ports render.zig: RenderState, the per-frame snapshot the
renderer consumes (rows, cells, styles, graphemes, selection,
highlights, cursor, colors), updated incrementally with Zig's full
redraw triggers and per-page/per-row dirty tracking. Cells are stored
struct-of-arrays; use the accessors.
- highlight.rs ports highlight.zig (untracked, tracked, flattened).
- formatter.rs ports formatter.zig: plain, VT and HTML output for
terminal, screen, page list and page, with selection, rectangle,
unwrap, trim, palette, codepoint maps, hyperlinks and pin/point maps.
Screen's test dump helpers now delegate to it.
Cargo.toml also picks up dependencies for the kitty graphics and search
modules that are being ported concurrently.
Test Plan:
- cargo test -p ghostty-terminal --lib (1243 passed; formatter 100/100,
render 15/15 Zig tests)
Second pass over the page memory model (done by Codex/gpt-6-astra in an
isolated worktree, reviewed and merged here):
- Resize/reflow now port Zig's incremental ReflowCursor algorithm with
page backfill and the same capacity growth/split sequence, instead of
rebuilding a snapshot, so page boundaries, pruning and tracked-pin
remapping match Ghostty.
- Point<->pin conversion for the active area starts at the list tail and
the viewport offset is cached, so hot-path operations no longer walk
the whole scrollback from the head.
- RefCountedSet reproduces Zig's observable ID reuse and error points.
- All 202 PageList tests are ported (plus 13 extra regressions).
With this, the five Screen/Terminal tests previously ignored as blocked
on PageList behaviour pass and are re-enabled.
Test Plan:
- cargo test -p ghostty-terminal (913 passed, 0 ignored)
- cargo clippy -p ghostty-terminal --all-targets -- -D warnings
Ports ZIG/src/terminal/Terminal.zig - printing with grapheme clustering
and Unicode widths, wraparound, insert mode, charsets, cursor movement,
scroll regions and left/right margins, erase/insert/delete, tabs, modes,
alternate screens, save/restore cursor, DECALN, full reset, palette,
mouse/focus/paste flags, kitty keyboard, titles/pwd, semantic prompts,
hyperlinks, protected mode, synchronized output and resize.
stream_readonly.rs implements ghostty_vt::stream::Handler, applying all
state-changing actions to a Terminal and ignoring queries; it is the
base for termio's side-effecting handler. StringMap uses the onig crate
for Oniguruma-compatible regexes (needed by Ghostty's URL regex).
Not yet wired: kitty graphics (hooks and dirty flags are in place where
Zig calls into it, storage is being ported separately) and the tmux
control-mode viewer.
Test Plan:
- cargo test -p ghostty-terminal (849 passed, 5 ignored; all 372
Terminal and 33 stream_readonly tests ported; ignored ones are blocked
on the PageList parity pass)
Completes the font engine port:
- shaper/run.rs ports run.zig: the RunIterator over terminal rows that
splits text runs at style/face boundaries, selection and cursor,
handles graphemes and ligatures; Shaper::shape_run shapes a run.
- shared_grid_set.rs ports SharedGridSet.zig: grids keyed by a config
derived key, handed out as Arc<SharedGrid>.
- Font-related types now have one canonical definition in ghostty-config
(Variation, Descriptor, CodepointMap, metric modifiers, freetype load
flags, synthetic style, shaping break) which the font crate re-exports.
MetricModifier::apply_i32 now saturates to -i32::MAX like Zig.
- The 23 terminal-driven harfbuzz shaper tests are ported, printing via
Screen until Terminal lands.
Test Plan:
- cargo test -p ghostty-font (157 passed, 3 ignored - also skipped in
Zig); Devanagari/Chakma/Bengali tests return early without system fonts
- cargo test -p ghostty-config (255 passed)
Ports ZIG/src/terminal/{Screen,ScreenSet,Tabstops,Selection}.zig on top
of the page/PageList layer. The cursor holds a TrackedPin; Zig's cached
page_row/page_cell pointers become accessor methods. Selection methods
take the PageList explicitly because tracked bounds are handles.
Screen tests use minimal plain-text dump/selection-string helpers that
follow the formatter's semantics; they will delegate to the real
formatter once formatter.zig is ported.
Gaps found in the PageList layer are recorded for the parity pass in
docs/rewrite/notes/ghostty-terminal-pagelist-requests.md; three resize
tests are #[ignore]d pending those fixes (PageList::resize keeps
trailing blank rows Zig drops). Kitty image storage and StringMap are
placeholders.
Test Plan:
- cargo test -p ghostty-terminal (443 passed, 3 ignored; Screen 183/184,
Selection 18/18, Tabstops 4/5 - skipped tests use allocator failure
injection)
Ports the terminal-independent half of ZIG/src/renderer (OpenGL only):
- opengl/*: buffers, frames, pipelines, render passes, samplers,
targets, textures and the OpenGL GraphicsAPI backend on top of glow;
the GTK GLArea glue is replaced by a get_proc_address loader closure
- the GLSL shaders, copied verbatim and embedded; uniform/vertex structs
as bytemuck Pod types with std140 offsets asserted in tests
- shadertoy custom shaders converted with naga (GLSL in -> validate ->
GLSL 430 out) instead of glslang + spirv-cross
- size (screen/grid/cell/padding math), cursor style logic, backend
health, options and message types
The crate opts into unsafe_code = "deny"; unsafe glow calls live only in
opengl/gl.rs. A headless EGL integration test builds every pipeline and
the converted shadertoy shaders on Mesa and reads back rendered pixels.
Note: Zig's shadertoy Uniforms order the selection background/foreground
colors opposite to the GLSL block (likely an upstream bug); kept as in
Zig for parity and recorded in the notes.
Deferred to the next renderer pass: generic, cell, image, link, row,
State, Thread, Overlay (need terminal render state).
Test Plan:
- cargo test -p ghostty-renderer (33 tests incl. tests/egl_headless.rs)
Ports ZIG/src/apprt/{action,structs,surface,ipc,runtime}.zig into
ghostty-apprt: the Action enum performed by the core on the app runtime
(all 65 variants with docs), Target<S> generic over the runtime's
surface handle, clipboard/size/scale/selection structs, the core->surface
Message enum with a Mailbox over an AppMailbox trait, and IPC action
types for +new-window.
Owned Strings and Arc<Config> replace Zig's borrowed slices/pointers.
Scrollbar and RendererHealth are local stand-ins until core integration.
The embedded C API and browser runtime are out of scope.
Test Plan:
- cargo test -p ghostty-apprt (16 tests)
Ports ZIG/src/cli into ghostty-cli: action detection/dispatch with
per-action --help, and the actions help, version, list-actions,
list-colors, list-keybinds, list-themes (plain listing plus an
interactive ratatui browser mirroring Ghostty's libvaxis UI),
show-config, validate-config, edit-config, crash-report (listing),
ssh-cache and boo (235 embedded frames).
Verified byte-for-byte against the installed Ghostty 1.3.1 for stdout,
stderr and exit codes of most actions, incl. tty output in a pty at
widths 20-200. Known differences: +list-colors --plain prints all 782
colors (Ghostty truncates at 617 because it never flushes), +version
has placeholder build info until build_info::set is wired up.
Deferred: list-fonts, show-face (need font discovery integration) and
new-window (needs GTK IPC); they return NotYetAvailable for now.
Test Plan:
- cargo test -p ghostty-cli (86 tests)
- cargo run -p ghostty-cli --example cli -- +list-keybinds --plain
and diff against `ghostty +list-keybinds --plain`
Ports the rest of ZIG/src/font for the freetype/fontconfig/harfbuzz
backend: face loading and rasterization (synthetic bold/italic, color
emoji bitmaps, glyph constraints for nerd font icons), fontconfig
discovery, DeferredFace, Collection, CodepointResolver, CodepointMap,
SharedGrid, opentype table parsers, the nerd font attribute table, and
the harfbuzz shaper with feature parsing and shaping cache.
Embedded fonts (JetBrains Mono 2.304 variable, Symbols Nerd Font 3.4.0,
Noto emoji) and the test fonts from Ghostty live in res/ with their OFL/
MIT licenses.
The crate opts into unsafe_code = "deny"; FFI is confined to ft.rs,
fontconfig.rs and hb.rs with SAFETY comments. Glyph resampling uses an
stb-style resampler that is not bit-identical to stb.
Deferred to the next font pass (needs ghostty-terminal/config):
shaper/run.zig, SharedGridSet.zig and the 23 terminal-driven shaper
tests. Config-facing types are mirrored locally in config_types.rs.
Test Plan:
- cargo test -p ghostty-font (139 tests)
First cut of the terminal core memory model from ZIG/src/terminal:
size, point, style, hyperlink, ref_counted_set, page and PageList.
Design (see docs/rewrite/ARCHITECTURE.md decisions 2-4):
- Cell/Row are 8-byte u64 wrappers with Zig's exact bit offsets.
- Page owns row/cell Vecs plus style set, grapheme and hyperlink maps;
Page::layout reproduces Ghostty's byte-size formula on 64-bit Linux so
scrollback-limit pruning matches.
- PageList keeps nodes in a generation-checked slab with a free list and
list-owned tracked pins addressed by handles.
This is explicitly partial (docs/rewrite/notes/ghostty-terminal-
pagelist.md): 151/202 PageList tests ported; reflow rebuilds a snapshot
instead of Zig's incremental ReflowCursor; point<->pin conversion walks
from the list head (no active/viewport caches); RefCountedSet doesn't
reproduce probe-dependent ID reuse. A follow-up pass finishes parity.
Test Plan:
- cargo test -p ghostty-terminal (239 tests)
Ports the parts of Ghostty's IO layer that don't depend on the terminal:
- pty.zig: pty pair, window size, mode, child-side setsid/TIOCSCTTY;
master is CLOEXEC with IUTF8 set
- Command.zig: fork/execvpe with Ghostty's exact child setup (stdio
dup2, best-effort chdir, rlimit restore, os/runtime pre-exec hooks,
cgroup handling) and exit status decoding
- shell_integration.zig for bash/zsh/fish/elvish/nushell plus feature
flags; scripts copied verbatim to resources/shell-integration/
- terminfo generator for xterm-ghostty, byte-identical to Zig's encode
output (golden file produced with the real Zig code)
This crate opts into unsafe_code = "deny" (fork/exec need it) with
allow + SAFETY comments on minimal items.
Integration left: config-derived option types are local stand-ins;
cgroup D-Bus scope creation is a closure hook; Exec/Termio/Thread/
stream_handler wait for ghostty-terminal. Pty now closes both fds on
drop (Zig never auto-closed the slave) - to re-check when wiring Exec.
Test Plan:
- cargo test -p ghostty-termio (52 tests, incl. real pty spawn test
expecting "hi\r\n31 97\r\n" from `echo hi; stty size`)
Ports ZIG/src/config (minus C/WASM APIs) and cli/{args,CommaSplitter,
diagnostics}.zig into ghostty-config:
- all 202 options with exact names, types, defaults and verbatim docs,
declared through one config_struct! macro; Zig's comptime reflection is
replaced by the ConfigField/CliTarget traits
- loading: default XDG files, -e, config-file includes (optional '?',
cycle detection), themes incl. light:/dark: pairs, conditional config,
replay, finalize() derived defaults, clone/changed diffing for reload
- Linux/GTK default keybinds built on ghostty_input::binding::Set
- formatter producing +show-config output
Verified against the installed Ghostty 1.3.1: `+show-config --default`
and `--default --docs` match byte for byte (except gtk-opengl-debug,
which differs between debug/release builds), as do two complex loaded
configs.
Open items (docs/rewrite/notes/ghostty-config.md): url regex needs an
Oniguruma-compatible engine (onig) in the renderer; some font/terminal
types are local copies awaiting integration; KeyRemapSet equality is
order sensitive unlike Zig.
Test Plan:
- cargo test -p ghostty-config (255 tests)
- compare `ghostty +show-config --default --docs` with our formatter
Ports ZIG/src/terminal/stream.zig: the Stream feeds bytes through the
UTF-8 decoder and parser and dispatches every CSI/ESC/OSC/DCS/APC and
C0/C1 control to a Handler as a high-level Action (all 95 Zig
variants). Zig's comptime handler interface becomes a Handler trait with
an associated error type, a required vt() and an optional vt_raw() hook.
Performance: next_slice() processes 4 KiB chunks, finds ESC with memchr
and decodes printable runs in bulk (scalar port of ZIG/src/simd's
index_of / utf8_decode_until_control_seq), plus the CSI parameter fast
path.
Terminals must construct the stream with Stream::new_alloc so the OSC
parser accepts allocating commands (colors, OSC 133), as in Zig.
Minor differences: after a stray UTF-8 byte the rest of the chunk
returns to the fast path, and a spurious Zig warning after CSI 2/5 W is
dropped.
Test Plan:
- cargo test -p ghostty-vt (448 passed; 37/38 stream tests ported,
the skipped one only exercises the C ABI)
Ports ZIG/src/input (except macOS keymaps) into ghostty-input:
- key, key_mods (incl. RemapSet), the physical keycode table
- key_encode: legacy, modifyOtherKeys and kitty keyboard protocol
encoders, function key tables
- Binding: all keybinding actions with their user-visible docs (for
+list-actions), triggers, sets with sequences, chains, leader keys and
key tables, and formatting back to config strings
- command palette defaults, mouse, paste safety checks, kitty helpers,
links, helpgen action docs
Deviations (docs/rewrite/notes/ghostty-input.md): Mods.super is named
super_; case folding uses char::to_lowercase plus Ghostty's special
cases instead of uucode tables; chain parents are trigger paths instead
of pointers; a Zig bug where chained leaves inside sequences corrupted the
shared prefix when formatting is fixed (covered by a test).
Integration left: building encode/paste Options from terminal modes,
and implementing the EntryFormatter trait in ghostty-config.
Test Plan:
- cargo test -p ghostty-input (220 tests; 8 macOS-only skipped)
- cargo clippy -p ghostty-input --all-targets -- -D warnings
ghostty-unicode: Ghostty computes codepoint properties with the uucode
Zig package (v0.2.0, Unicode 17.0.0). There is no Rust equivalent, so
a trimmed UCD set is vendored in ucd/ and build.rs re-implements
uucode's derivations: cell width rules incl. Ghostty's overrides for
emoji modifiers and Prepend, grapheme break classes with the
compile-time grapheme_break state table, the is_symbol set, and emoji
presentation. Lookups are three array indexes per codepoint. Validated
against the official GraphemeBreakTest.txt.
ghostty-datastruct: split_tree (used for GTK splits; f16 ratios so
rounding and debug diagrams match Zig), circ_buf, lru, cache_table,
blocking_queue, segmented_pool, message_data, comparison,
array_list_collection. intrusive_linked_list is not needed (lru is
index based). lru now reports the evicted (old) key, Zig reported the
new key, which appears to be a bug.
Not yet covered: case_folding_full (needed by input bindings).
Test Plan:
- cargo test -p ghostty-unicode (16) -p ghostty-datastruct (88)
- cargo clippy for both crates with -D warnings
Ports ZIG/src/os for Linux into ghostty-os: XDG dirs, home dir, hostname,
env/PATH helpers, passwd lookup (via nix), shell detection, resources
dir discovery, string encodings (printf-q, URL percent), systemd
sd_notify, i18n via gettextrs, xdg-open, desktop/cgroup/kernel info,
temp dirs, URI parsing (port of std.Uri incl. Ghostty's extra options),
and a zbus-based Flatpak HostCommand implementation.
The crate stays free of unsafe. Consequences, all tracked as
TODO(integration) in docs/rewrite/notes/ghostty-os.md:
- locale::ensure_locale is a no-op (setlocale/setenv are unsafe; GTK
calls setlocale itself); setenv/unsetenv are not exposed.
- passwd's Flatpak branch needs the termio pty and falls back to the
sandbox entry for now.
- FlatpakHostCommand's D-Bus path is untested (no portal here).
Intentional fix: a leading '@' in NOTIFY_SOCKET is treated as an
abstract socket.
macOS/Windows/WASM modules are out of scope.
Test Plan:
- cargo test -p ghostty-os (88 tests)
- cargo clippy -p ghostty-os --all-targets -- -D warnings
Ports ZIG/src/font/{Metrics,Atlas,Glyph}.zig and the whole sprite font
(font/sprite/**): box drawing, block elements, braille, branch/git
graph symbols, geometric shapes, powerline, and the symbols for legacy
computing (+ supplement, incl. the octants table).
Ghostty draws sprites with z2d; we use tiny-skia for path coverage,
composited onto an alpha8 canvas, while following the Zig geometry
(positions, thickness, rounding). Comptime discovery of draw functions
is replaced by explicit, overlap-checked codepoint range tables.
Upstream reference sheets are vendored in testdata/ and compared with a
tolerance: braille and U+1CD00 are pixel-identical; other sheets differ
only in antialiasing on thin diagonals/curves. Review renders are written
to target/sprite_sheets/.
The crate temporarily drops its config/unicode/terminal deps until the
rest of the font engine is ported (Phase 3).
Test Plan:
- cargo test -p ghostty-font (49 tests incl. reference sheet comparison)
- inspect target/sprite_sheets/review-all-18x36.png
Ports the parsing half of ZIG/src/terminal into the ghostty-vt crate:
- Parser state machine with a compile-time generated parse table and
the UTF-8 decoder
- OSC parser incl. all sub-parsers (titles, colors, clipboard, hyperlinks,
semantic prompts/OSC 133, OSC 9 / ConEmu, iTerm2, kitty clipboard,
color and text-sizing protocols, context signals)
- CSI, SGR, modes table with save/restore, charsets, ansi, device status,
mouse shapes, APC, DCS (incl. XTGETTCAP), tmux control-mode parser
- color palette / X11 color names, kitty color and graphics command parser
Deviations from Zig (documented in docs/rewrite/notes/ghostty-vt-W*.md):
parser actions own their payloads instead of borrowing parser buffers;
OSC strings are Vec<u8>; non-exhaustive Zig enums gain an Other(raw)
variant; tmux regexes replaced by equivalent hand-written matchers.
Known follow-up: semantic_prompt.rs carries local copies of the printf-q
and percent decoders that belong in ghostty-os.
Test Plan:
- cargo test -p ghostty-vt: 395 passed, 1 ignored (skipped in Zig too)
- cargo clippy -p ghostty-vt --all-targets -- -D warnings: clean
Start of the full Rust rewrite of Ghostty 1.3.1 (reference source in
../ghostty). Sets up a workspace whose crates mirror Ghostty's Zig modules
(vt, unicode, datastruct, os, input, config, terminal, font, renderer,
termio, core, apprt-gtk) so porting work can proceed in parallel per crate.
Also adds:
- docs/rewrite/{ARCHITECTURE,PLAN,STATUS,AGENT_GUIDE}.md: crate map, core
design decisions (safe Rust, slab-based PageList, logical capacity
accounting), phased plan, progress tracker, and porting rules.
- Workspace clippy config relaxing pedantic lints that are pure noise for
low-level terminal code (casts, long functions).
- Shared vt types needed by several work packages up front: kitty
keyboard flags (kitty/key.rs) and the CSI separator bitset (SepList).
Test Plan:
- cargo test -p ghostty-vt (3 tests pass)
- cargo clippy -p ghostty-vt --all-targets -- -D warnings
ddidderr