Three implementation blockers and one evidence-labelling defect, all
from review.
THE WIRE TARGETS MULTIPLIED ONE NOTCH TWICE. `apply_wheel` banked in
LINES (notch x 3), then emitted one event per banked unit, and the
receiver applied its own SCROLL_LINES = 3 to each. So LineDelta(0, 1)
moved a panel or terminal NINE lines while the document moved three ---
and it broke the "exactly one viewport effect" witness this slice owes
before it was written. The accumulator now banks in NOTCHES, the unit
that survives the wire, and the three-line/column step is applied
exactly once at the point of effect. Pixel deltas divide by a notch's
pixel height rather than a line's.
THE MINIMAP SCROLLED THE DOCUMENT SIDEWAYS. §2a rules the minimap's
horizontal axis inert; the shared local arm was passing its banked x to
`scroll_by_columns`. It keeps its own vertical bank (B6) and no longer
moves the document horizontally.
B3's UPPER BOUND SAW ONLY THE VISIBLE SLICE. `widest_display_columns`
scanned `self.buffer.lines`, which `rebuild_code_slice` populates from
the visible window plus overscan, so every off-screen line was excluded:
horizontal scrolling clamped prematurely and the bound moved as the view
scrolled vertically. It now reads `current_text` --- the whole document
--- through a display-column rule shared with the minimap rather than a
third copy. Cost is O(document) on the wheel path, which is a real risk
against this project's wall-clock budgets and is recorded on the
function rather than pre-optimised: a cache needs an invalidation key,
and the wrong key is a worse defect than a measurable scan.
AND THE R-NAMES WERE WRONG. The rows I called R4 and R5 test
document/chrome sharing and minimap independence; the framing's R4 and
R5 are the two BUFFER-REPLACEMENT resets. The row I called R1 is basic
accumulation; the real R1 is cross-axis. Renamed, and R1's body now
asserts what R1 says --- a sub-tick horizontal followed by a sub-tick
vertical over the same surface reaches no tick on either axis.
The resets themselves are now implemented, on the buffer-replacement
path beside `code_scroll_left`, as two separate clears so that omitting
one is individually visible. Their witnesses --- an actual replacement
through the harness --- are still owed and are labelled as such.
Levi Neuwirth
0f29530dd8