Record the clarity sweep and point the handoff at 7e2b4cd

docs/HANDOFF.md

@@ -6,8 +6,8 @@ found is in `docs/LAYOUT_LOG.md`.
 
 ## The Iris layout repair is submitted
 
-**Iris PR #19** (`layout/one-ask`) replaces closed #18. The tip is `6c84b6f`,
-and past the reviewed `cadfba0` it is four rounds, each described in
+**Iris PR #19** (`layout/one-ask`) replaces closed #18. The tip is `7e2b4cd`,
+and past the reviewed `cadfba0` it is five rounds, each described in
 `docs/LAYOUT_LOG.md`:
 
 - **The repair**, `add6774` and `84dad21` -- collapsed-share placement,
@@ -16,6 +16,9 @@ and past the reviewed `cadfba0` it is four rounds, each described in
 - **The vocabulary and the container API**, `5642f20` through `58ce74d`.
 - **Naming**, `55df32a` through `40b89c1`.
 - **A sweep over the logic those names exposed**, `8d2b7a5` and `6c84b6f`.
+- **A clarity sweep**, `3da1c71` and `7e2b4cd` -- naming the pairs layout
+  returns, `Span::slot`, and a diagnostic that printed the rel base while
+  calling it the box.
 
 The settled design of the last three is in `docs/LAYOUT.md` under "Three
 names, and the one argument that says them". Bryan settled the API over
@@ -35,7 +38,7 @@ the **cold dump**. `layout_dump` over 400 depth-5 trees is 34,492 boxes, and
 it is the only thing that catches two same-typed values being swapped, which
 is the failure mode of a rename or a move. The repair moved 650 of those
 boxes, all from the collapsed-share correction; every commit since has been
-byte-identical to `84dad21`.
+byte-identical to `84dad21`, the clarity sweep included.
 
 **Only when the change can alter what layout computes**: the three seed scans
 -- 400 at depth 5, 1,000 at depth 6, 2,000 at depth 4. They cost about a

docs/LAYOUT_LOG.md

@@ -191,17 +191,40 @@ The descriptions above preserve the original failure at `cadfba0`.
 Everything about naming is done: the unswept `extent`, the two same-typed
 boxes on `ActiveData` and `Painter`'s four holds accumulators in `5642f20`,
 `Part::All` in `aeb60e5`, and `Place`/`Part` themselves in `58ce74d`. The
-settled vocabulary and the ask API are in `docs/LAYOUT.md`. What is left:
+settled vocabulary and the ask API are in `docs/LAYOUT.md`.
+
+The clarity sweep of `3da1c71` and `7e2b4cd` closed the first three items
+that stood here. Both are cold-dump identical to `6c84b6f`, so none of it
+moved a box:
+
+- `Answer` {size, holds} and `Drawn` {answer, drawing_holds} replace
+  `(Size, LayoutHolds)` and the three-tuple with two `LayoutHolds` in it.
+  `try_reuse` answers `bool` rather than `Option<()>`.
+- `Span::along` is `Span::slot`; `far` is `row`, `shares` is `has_room`
+  beside a named `any_leftover`, and `reached` guards on the weight it
+  divides by rather than on the numerator.
+- `DrawInfo::px` was the rel base in pixels, and all three readers printed
+  it as the box the widget drew in. Removed; each reads
+  `region.to_px(window)`. `Placing::window` existed only to feed it.
+- `diag::outside` holds the 23 counter lines that were inside `try_reuse`.
+- `ActiveData::is_region_node` replaces four copies of
+  `move_idx != parent_move`; `Axis::BOTH` replaces `AXES` in three modules;
+  `Len::rel_min`, `rel_max` and the unused `select_len` are gone.
+
+What is left, none of it urgent:
 
-- `draw_inner` returns `(Size, LayoutHolds, LayoutHolds)`, two same-typed
-  values ordered by convention. A named pair makes the swap unwriteable.
-- `DrawInfo::px` is computed at all four construction sites and read only by
-  `diag::draw_request` and two `debug_assert!` messages. Compute it in the
-  assert.
-- The `layout-diagnostics` block inside `try_reuse` is 23 lines of counters
-  in the middle of the decision; one `diag::outside(...)` call would keep
-  the branch readable.
 - `widget_at` does three linear scans per child (`children.contains`,
   `under.iter_mut().find`, `depend_on`), so a span of *n* children is
   O(n^2) per draw. Not a problem at today's sizes; it is worth knowing
   before a long transcript list lands on it.
+- `PlaceSpan` is private to `place.rs`, so `Painter::in_parent` asks five
+  yes/no questions (`stated_rel_base`, `is_sized`, `within_span`,
+  `narrows_rel_base`, `does_fill`) about a three-case enum instead of
+  matching it. Two of those questions are redundant with one another --
+  `Sized` always states a rel base -- but only because nothing constructs
+  a `Sized` without one, which nothing states. `pub(crate)` on the enum
+  would let `in_parent` read as its three cases.
+- `DrawInfo` and `ActiveData` both carry `placed` and `asked`, two
+  `PlaceDesc` fields distinguished only by position in every literal.
+  They are genuinely different and documented, but the names are past
+  participles with no operand; a rename is Bryan's vocabulary call.