Stage 4 of the QoL arc, framing revision 4 (approved). Under
`truncate`, text past the right edge was UNREACHABLE; moving the cursor
now brings it into view. Automatic only — no commands, no bindings, no
new interaction island (Q#HS2).
THE CONTRACT. `view_left` is an unsnapped per-window display column
(Q#HS7(a)), and each line derives its own effective edge during the
walk it already performs from column 0. Starting at 0 is not laziness:
tab expansion depends on the absolute column from the line start, so a
walk beginning at the edge would put tab stops in the wrong place. The
walk stays line-absolute and only the emit translates.
Where the edge bisects a wide glyph on a given line (Q#HS7(c′)), its
trailing cell paints a styled BLANK rather than a `Continuation` — that
glyph means "the cell before me is a wide glyph's head", and here that
cell is off-screen, so emitting it would name a cell nobody painted.
The mapping designates that cell to the glyph's START byte, which keeps
`byte_at_place` total over visible cells and makes the character the
user scrolled toward clickable. Tabs keep FORWARD rounding (Q#HS7(c″))
— preserved, not chosen.
DECORATIONS TRAVEL WITH THE TEXT. The first version of this commit
translated the base glyph walk and nothing else, which split the frame
in half: at `view_left = 10` a glyph from source column 10 painted at
screen column 0 while its syntax style, diagnostic underline, search
wash and `BufferStyleOverlay` span painted at screen column 10 — or
vanished. Decorations drifting off the characters they describe,
silently, and only once a window had been scrolled.
Every such site carried the same two lines (`start_col.min(max_cols)`,
`end_col.min(max_cols)`), correct only while the left edge was pinned
at zero. `Viewport::visible_cols` is now the one rule all FIVE adopters
share — syntax/LSP styling, diagnostic underlines, search washes,
`BufferStyleOverlay`, and the selection painter — so a future decorator
inherits the translation instead of re-deriving it. It also subsumes
the old `end_col <= start_col` guard rather than sitting beside it.
`StyleSpanOverlay` and `VirtualCellOverlay` are deliberately untouched:
they are documented as viewport-relative, so translating them would be
the mirror defect.
The selection painter was nearly a sixth site with its own copy of the
rule, which I justified by a width it supposedly needed and the
viewport lacked. That was FALSE — the render viewport's
`cell_size.cols` is already `rect.size.cols - gutter_w` and its origin
already sits past the gutter. It now takes that same viewport and drops
its `rect`/`gutter_w` parameters entirely. A canonical rule with one
honest exception is not canonical.
The selection painter had the same defect with a worse failure mode: it
asked `pos_to_display` through the LIVE context, which returns `None`
for a position left of the edge, so a selection beginning off-screen
and reaching into view took `continue` and painted NOTHING. That is the
common shape, not an edge case — select rightward from column 0 past
the window width and the view scrolls with the cursor.
TWO THINGS THE TESTS FOUND, both in `pos_to_display`. My framing note
said a caret sits between characters so never lands inside a glyph;
true for the caret, false for the DESIGNATION direction — the glyph's
start byte must map to its visible trailing cell, so `screen_col` needs
the straddle rule and not a bare subtraction. And the `take == 0` early
return short-circuited the translation entirely, so byte 0 looked
visible at every offset.
`view_left` is inert under `wrap` BY CONSTRUCTION —
`LayoutCtx::effective_left` and `Viewport::left_edge` return 0 while
wrapping — rather than by every caller remembering.
Persisted per leaf at DESKTOP_VERSION 1 (Q#HS5) with both approval
conditions: `#[serde(default)]` and a literal v1 JSON fixture omitting
the field, hand-written because a generated one would gain the field
and prove nothing.
Also: `view_left: window.view_left` in the render viewport, not a
literal 0. My mechanical fill put 0 there and it is EXACTLY the
`aa3cd4d` defect — coordinates and the indicator following the scroll
while the painter stays pinned at column 0.
BITE, per clause. Forcing `bisected = false` fails the multi-line
straddle witness; dropping the backward designation fails the
round-trip witness; removing `#[serde(default)]` fails the v1 fixture;
pinning `visible_cols` to an absolute clamp fails all three decorator
witnesses; restoring the selection painter's live-context lookup fails
the off-screen-start selection witness. Each alone. And with selection
now reading the shared helper, pinning `visible_cols` to an absolute
clamp fails the selection witnesses TOO — which is the check that the
duplication is really gone rather than merely reworded.
One unrelated red, logged as R7 in ci-red-signatures.md — the first
this session with a COMPLETE signature, so a matchable row rather than
a U note. `pmacs-gpu`'s managed-retry attach hit a BrokenPipe once
under full-sweep load and did not reproduce (6 isolated runs plus a
clean 113-target sweep). Per the rerun rule that is intermittence only,
and the row explicitly does not claim harmlessness. Not attributed to
this lane: Stage 4 touches no `pmacs-gpu` file and adds no wire
surface.
Gates: fmt; clippy --workspace --all-targets -D warnings, both
configurations; `cargo test --workspace --no-fail-fast -- --skip
basedpyright` 113 targets exit 0, and the same with --features crdt,
113 targets exit 0; git diff --check. No protocol change, so no version
bump and no protocol-bump matrix.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
pos_to_display and display_to_pos now take a LayoutCtx and DisplayCoord
carries a sub_row. The asymmetry is the whole audit strategy, and it
played out as designed.
Breaking on the way in: adding a required parameter turned the audit
into 61 compiler errors instead of a grep. Additive on the way out:
sub_row defaults to 0, so overlay_paint's `row - view_top` and vertical
motion's bounds check stayed CORRECT rather than merely findable ---
neither needed touching. row is still the source line. Redefining it as
a visual row would have broken both silently.
Two structural gaps this surfaced, neither in the framing:
Window recorded last_visible_rows but no width, so the coordinate
callers --- vertical motion, paging, overlay placement --- had nothing
to build a context from. Added last_content_cols, taken from the
viewport the renderer actually used rather than recomputed: a second
derivation could disagree, and the disagreement would show only as a
cursor on the wrong row. Content width, not window width, because the
gutter grows at the line-count digit boundary.
The mode had the same problem one level up. It is buffer-local and the
registry has no ambient buffer, so only the driver can resolve it ---
but every consumer holds a window, not a registry. Window::last_wrap is
recorded beside the width and read through Window::layout_ctx(), so
there is ONE resolution consumed everywhere. When ui.line-wrap is
registered, only the driver changes and all twenty call sites become
wrap-aware together. The alternative, each caller resolving for itself,
is how two callers end up disagreeing about one buffer.
One real regression, caught by the render tests rather than reasoning:
generalising row_of_byte into place_of_byte lost the boundary rule. A
byte landing exactly on a row edge reported (row, max_cols) instead of
(row+1, 0), so a viewport anchored there painted the wrong row. The fix
is the rule framing section 7 already settled --- the wrap position is
owned by column 0 of the NEXT row, because that cell always exists and
(row, max_cols) does not.
Five coordinate witnesses. Identity on every cursor boundary of a line
containing a tab and a CJK glyph, across four widths; projection to the
codepoint start for interior bytes, unchanged by wrapping; the two
distinct adjacent codepoints across a break mapping distinctly; row
staying the source line; and a truncate control. They bite --- forcing
the wrap branch off fails three, including the round trip.
Gates: fmt, workspace clippy -D warnings, diff --check, --lib 1912/0,
crdt 2092/0, tab_width 2/0, folding 21/0, gui_zoom 15/15.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Inert by construction. Adds the type and the Viewport field, sets all
31 construction sites to Truncate, and changes no rendering: --lib is
1900/0 and crdt 2085/0, the same counts as the parent commit.
The field is required rather than defaulted on purpose. A default would
have let 31 sites stay silent about which behavior they meant; a
required field makes each one state it, so the pre-existing sites now
read as deliberately unwrapped rather than merely untouched. The
compiler enumerated them, including five integration tests --- Viewport
is public API, so this is a real break, and the break is the point.
The render driver is pinned to Truncate too. The wrap path does not
exist yet, and exposing a mode before the cursor mapping honors it
would ship a setting that renders one thing and navigates another ---
the shape of defect this lane exists to remove, not add.
Two notes on getting here, since both were nearly landed:
The first mechanical patch matched every `folds,` line and put a wrap
field into function call sites and a FoldStore literal. Scoping the
insertion to Viewport literals cut it from 40 sites to 31. The compiler
caught it, but only because a struct field cannot be mistaken for an
argument; a same-arity call would have compiled.
While rewriting the character walk I changed the wide-character edge
case --- a double-width glyph with one cell left now breaking instead
of painting a lone lead cell. That is arguably better behavior and it
is NOT this commit's to make: Truncate must be byte-identical, and an
"improvement" smuggled in beside a refactor is how identity cases stop
being identity cases. Reverted; the walk is untouched.
Gates: fmt, workspace clippy -D warnings, diff --check, --lib 1900/0,
crdt 2085/0, tab_width 2/0, listview 26/0, compile_mode 73/0,
folding 21/0.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Implements docs/folding-stage2-framing.md rev 4. The daemon grid
renderer now consults the fold store: hidden lines are omitted, rows
below shift up, and every consumer that assumed
`display_row = source_line - view_top` routes through one shared
projection. No wire schema change and no protocol bump (Bet B6) — the
collapse is entirely daemon-side; the GPU path is Stage 3.
The spine (Q#FD12) is `src/fold_view.rs`: a `VisibleLineMap` derived
from `FoldRegistry::folds` plus a window's line offsets and never
stored. Its unit is a merged **hidden component** — overlapping OR
adjacent hidden intervals unioned, each keeping the one visible
`head_line` and that line's exact `head_position`. Adjacent intervals
merge because the later fold's head is itself hidden, which is what
makes nesting, shared heads, and crossing overlap all resolve to a
head that can actually render (round-3 F2).
Instances are short-lived and built **per rendered window** and **per
command/event operation**, never once per frame: `paint_frame` renders
several windows that may show different buffers, so a singleton would
leak one pane's folds into another (round-2 F2). The render instance
rides on a lifetime-bearing `Viewport<'a>` as `Option<&'a
VisibleLineMap>` — a shared ref is `Copy`, so `Viewport` stays `Copy`
(Bet B7).
Rendering:
- `TextView::render` walks visible lines; the head line gets a
trailing content-area ellipsis (Q#FD13).
- The gutter walks visible lines too: Absolute keeps the raw `line+1`,
Relative/Hybrid measure VISIBLE distance anchored on the cursor's
visible head (Q#FD14). The fold glyph takes the col-0 sign cell only
when a gutter exists — line numbers default to Off, so with no gutter
the ellipsis is the sole marker (Q#FD20, round-1 F3). A diagnostic
clamped onto the head wins that cell by paint order.
- A diagnostic on a hidden line clamps its SIGN to the outermost
visible head (most-severe merge); the squiggle needs a real row, so
only the sign clamps (Q#FD15).
- Caret, local selection endpoints, and peer cursors project via
`visible_position_of` — the head row AND the head's end-of-content
column, never an arbitrary column (round-2 F3). Peer presence derives
the RECIPIENT window's map.
- Style/search/completion overlays route through
`Viewport::row_offset_of`; the mode-line indicator reckons in
visible-line space.
Command/event time is scoped per frontend (Q#FD21): a
`fold_projection` flag on `FrontendView`, set at attach from the
negotiated `semantic_render` bit (grid ⇒ true, semantic ⇒ false until
Stage 3, LOCAL ⇒ true) and never inferred from a `FrontendId` (Bet
B8). Without it, shared `EditorCore` motion would make a simultaneous
unfolded GPU session's cursor skip lines it still displays. The map's
two axes stay separate (round-3 F1): the acting frontend supplies the
policy, the operation's TARGET window supplies the buffer — a wheel
event names a pane without activating it.
Motion (Q#FD17, ruled: include), paging, wheel, the click inverse, and
the auto-scroll clamp all step by visible lines under that gate;
motion from a hidden logical cursor normalizes to the visible head
first. `view_top` stays a source-line index (Bet B5), set only via
`clamp_view_top` so it never rests hidden.
Unfold widening (Q#FD19): the pre-edit unfold moves to the top of
`apply_active_edit` — one funnel that subsumes the six primitives'
calls and covers yank + query-replace, both of which place point at
the edit site first. Interactive Lua mutators hook the common
`run_buffer_edit`, above the managed/bypass split, gated on
`InteractiveCommandOrigin` AND the edit targeting that frontend's
active-window buffer. The remote/optimistic-CRDT path stays excluded
(Stage 3); undo/redo unfold stays deferred.
Acceptance: `tests/folding_stage2_acceptance.rs`, 35 tests asserting
on the real `paint_frame` cell grid, covering framing items 1–14
including crossing folds, a nested deeply-hidden cursor, a split of
two different buffers with an inactive-pane wheel, and simultaneous
grid+semantic motion.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Q5BkezMppbpCgGAYk2ftxV
Share one fixed eight-column tab-stop contract across core and GPU renderers. Consolidate byte-to-display-column accounting, expand GPU code tabs with source provenance, align caret/hit/decoration geometry, and refresh minimap projection on edits.
Levi Neuwirth