Every edit bumped the buffer version (through SetDirty) and called
InvalidateFrom(0), so all cached spans and line states were discarded
and stateful highlighters re-lexed from row 0 to the viewport on each
keystroke.
Buffer mutators now report the row they changed (edited_at_), which
bumps the version and tells the engine to drop only rows from there
down; a row's highlighting depends only on rows above it. A version
change that arrives without that notice still clears everything, so a
missed path cannot show stale spans. The engine keeps states as a
contiguous vector and caches spans for every row it lexes. SetDirty no
longer touches the version: the edits themselves do, including undo
and redo back to the saved state (D9 still holds; its test now checks
the highlighting itself).
Typing near the end of a 100k-line C++ file: 46.3 ms -> 0.14 ms of
highlighting work per keystroke.
Audit finding P3.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- PieceTable::Insert/Delete adjust a valid line index directly (shift
later line starts, add or drop starts for inserted or deleted
newlines) instead of invalidating it, which forced a byte-by-byte
rescan of the whole buffer on the next line query. On a 38 MB,
1M-line buffer, insert + line query drops from 14.7 ms to 0.28 ms.
- The terminal and ImGui renderers fetch only the rows they draw
(Nrows + GetLineString) instead of Buffer::Rows(), which rebuilt a
string for every line of the file on the first frame after each edit.
Qt's line-count uses switch to Nrows().
ImGuiRenderer.cc was syntax-checked with g++ and clang++ against the
vendored ImGui headers; the GUI targets could not be built here (no
SDL2 or Qt6).
Audit findings P1, P2.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- Backspace and delete-char remove a whole UTF-8 character (they
removed one byte, leaving an invalid lead byte in the file), and
record the full character for undo.
- Left/right step over whole characters; up/down snap the column to a
character boundary and clamp the row, which also removes an unsigned
underflow in move-down when the cursor was past the last row.
- Horizontal scroll offsets are computed in display cells, the way the
terminal renderer draws (tabs, wide characters), instead of bytes, so
long non-ASCII lines no longer scroll to blank with the cursor off
screen. The mouse column mapping uses the same measure.
Audit findings B5, B6.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- Regex replace-all, reflow and kill-region replaced or deleted whole
rows, which added or left a stray newline when the text ended on a
last line without one. They now edit the byte range in place.
- Regex replace-all no longer matches the empty position after a final
newline. Before, a zero-width pattern such as ^ matched it, added a
line, and matched the new empty last row again: the editor hung.
- Kill-line on the last row kills an unterminated line with the newline
before it, and does nothing on the empty row after a final newline
(it used to record an undo step that added a line).
- The visual-line newline records its splits as one undo step, and
places the cursor correctly for a repeat count.
- Buffer::delete_text computes its byte range directly instead of
materializing every line it spans.
Audit findings D3, D4, D5.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
A secondary GUI window shared the primary's buffer vector but attached
buffers through its own SwapManager. Closing the window destroyed that
manager while buffers still held its recorders, so the next edit called
into freed memory; Rehome through the wrong manager also dropped
journaling for the primary's buffers.
Audit finding M3.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
Claude