Pardes https://git.0x4200.cafe/pardes.git/atom?h=release-0.24 2026-08-27T12:47:39Z 2026-08-27T12:47:39Z Gabriel Schneider gbrls@0x4200.cafe 2026-08-26T21:58:37Z urn:sha1:29ac9be75fdcafbd7d05c15aa9eb8490d74caa98 ## A terminal row's ANSI colours survive being edited The loudest colour bug this editor had: one keystroke anywhere in a coloured shell row turned EVERY column of it grey. `EditAnchors` anchored a buffer line only when it was BYTE-IDENTICAL to the shell row it stood over, so a single differing byte dropped the whole row's colour projection. Worst shape is invisible: append past the pane's right edge, where the text is clipped, and the row looks the same and only its colour goes. Anchoring is byte-level now. An edit leaves the row's own bytes at both ends, and being the same bytes they keep the same colours; only what was typed has no cell under it, so only that takes none. Live, on real `fastfetch`: a 32-column blue run split into 6 + 26 around one typed character. Three defects underneath it, all found by machinery rather than by reading: * A JOIN removes a buffer line while the buffer's covered span grows, so `lines == covered` and both aligned guesses — Nth line over the Nth covered row, and the same counted from the bottom — resolved to the SAME wrong row. Every untouched row below a join went plain. Anchoring is now a streaming monotone matching: one shell-row cursor that only ever moves forward, advanced once per buffer line, linear in the buffer where the version before it was quadratic. * An EMPTY line is not evidence. Splitting a row makes one, it equals every blank row in the span, and left free to look ahead it claimed the blank row below the last output and took every coloured row in between out of reach of the lines that owned them. * Reflow under a scrolled viewport. `PageList.getTopLeft(.viewport)` returns the viewport pin verbatim, x and all, while `PageList.pin` forces x to 0 — so after a reflow remapped a tracked pin into the middle of a row, the text pass dumped row 0 from that column while the colour pass paired the fragment with the row's FIRST cells. Row 0 wore its left half's colours until the pane snapped back to live output. `bodyText` dumps from column zero now, which is also what ghostty's own renderer draws. Also here: DECSCNM (reverse video) was silently dropped whenever `tty_filter` was off, because the raw path resolved a `.none` colour by role and never consulted the mode. The test that found the first two is the one worth keeping: random editing against an ABSOLUTE oracle — every row's own text names the colour it must have — because the differential oracle it replaced was blind by construction. It skipped the edited row, which is the row the user is complaining about. ## Esc returns to a pane without moving its view Esc in body normal mode runs `Last`, "the pane you were in before this one", and that went through `focusPaneLine`, which recentred a file on the target line unconditionally. So returning to a buffer repainted the whole screen to show a line that was already on it. `focusPaneLine` takes a landing now: `.center` for the three callers going somewhere you have not been (a look target, a path a pane already holds, `@pN:LINE:COL`), `.keep` for Esc. `.keep` leaves the view alone and lets `ensureCursorVisible` — which already existed and already scrolls by the minimum into the `scroll_off` band — be the only thing that may move anything. Not `line = 0`, which `focusPaneLine` already understands as "focus and touch nothing": a background pane's view can move while you are away, because the wheel scrolls the pane under the POINTER and a resize reveals no cursor, so the recorded cursor plus a minimal nudge is what actually gets you back. Ctrl-o and Ctrl-i keep centring, and the asymmetry is structural rather than arbitrary: `Last` only ever CROSSES panes, so the pane it lands on already holds the view you left it with, while `jumpBy` can land in the SAME pane, where a long in-file jump would arrive on the very top or bottom row with `scroll_off` lines of context on one side. Helix splits the same pair the same way — its jumplist centres, its buffer switch does not. One deliberate consequence: under `.keep` a PDF's page is not restored AT ALL, because a page reveal IS that pane's view and a reveal of the page you are already on still snaps `document_scroll_y` to that page's start, discarding where you had read to. When something moved the pane while you were away — the wheel again — Esc leaves it where the wheel left it, and Ctrl-o is how you reach the recorded page. ## host_io.zig: the machine-local half of a host, once `host.zig` is the seam. The part of the answer that is identical on every host with an operating system under it — fork a pane's shell, put bytes on a disk — was written FOUR times: in tty.zig, gui.zig, macos.zig and detached/server.zig. What those copies had in common says what they were for: all four were missing FD_CLOEXEC on the pty master, so in every shell pardes has shipped, a program in one pane could read another pane's terminal. One copy now, and the wire got smaller for it: `ServerMsg.spawn` is gone. A frontend never asked the server to fork anything — the server has an operating system under it and forks through `host_io` like every other host — and `decodeClient` lost the scratch buffer that message needed. 2026-08-10T12:17:07Z Gabriel Schneider gbrls@0x4200.cafe 2026-08-08T13:44:56Z urn:sha1:c3c8bbd8d8add99088c774c54bc1acf1e39ec895 Adds -Dplatform=macos, a fourth backend beside tty, gui and web. Zig keeps the core, the ptys, every effect and the worker threads; Swift owns NSApplication, the window, input translation, and drawing the cell grid with CoreText. They meet at a hand-written C ABI in src/macos/pardes.h, built as a static library the app links. The ABI is src/web.zig's boundary with the wasm removed, because both hosts are the same animal: someone else owns the clock, feeds events in through flat functions, and reads one packed cell buffer out. The browser proved the shape. The one divergence is that the browser has no processes and forwards every effect to JavaScript, whereas forkpty is right here, so src/macos.zig performs them — spawn, write, resize_pty, save_file, new_file, write_dump, open_link, set_clipboard. lsp, pipe and watch are answered with nothing and marked; the core already tolerates that, since the browser answers none of them either. This deliberately inverts ghostty's split, which was studied first and is written up in docs/ghostty-macos-notes.md. Ghostty hands Zig a bare NSView*, installs its own CALayer and owns the frame clock; Swift never renders. Pardes does the opposite because its frame is already a cell grid and CoreText draws one natively — the alternative is a second hand-rolled glyph atlas, which is what most of gui.zig's 4,300 lines already are. It would also have been written blind: the Swift half cannot be compiled here. What makes the scaffold verifiable rather than dead code is that the Zig half is ordinary POSIX and builds and tests on Linux. Borrowing ghostty's best trick, build.zig translate-C's the header into the test build and src/macos.zig asserts every constant, struct layout, and exported function's arity and widths against it. That guard earned its place immediately: pardes_scroll grew a cell coordinate after the Swift view had been written against the older form. Skipped, and named as the upgrade path in docs/macos.md: the Xcode project, xcframework, lipo and codesigning ghostty needs. All four exist for distribution; a dev build is a swiftc invocation and a directory with a plist. The Swift app is a scaffold and says so — every uncertain API spelling carries an UNVERIFIED marker, and no part of it has been compiled. tty is unaffected: 75/75 snapshot scripts and both unit suites pass.