Fix the stacked-structure geometry the census could not yet see

CHANGELOG.md

@@ -9,6 +9,35 @@ project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### Fixed
 
+- The Racket reference engine now answers the two coordinates inside a warichu block that
+  the other two engines already agreed on, which closes
+  [#23](https://github.com/P4suta/jlreq/issues/23) and
+  [#24](https://github.com/P4suta/jlreq/issues/24). `engines/racket/compose.rkt` reported a
+  line's `block_extent` as the sum of the note's own subline heights where that was larger
+  than the paragraph's own block size, so a note set at the paragraph's em rather than at
+  §3.4.2's half one made the line twice as deep as the paragraph set it; and it reported a
+  member's advance as its bare body, so a member standing before a Table 1 amount inside
+  its own subline — `cl-02` then `cl-01`, half of the note's own em — reported 500 where the
+  same engine placed the next member 750 units on. Both are one reading:
+  `docs/decisions/stacked-structure-geometry.md` now states what a block does on the block
+  axis (its sublines run *beside* the line, so their depth is not a depth the line reports)
+  and what Table 1 does inside one (a note's text is ordinary text, so the boundary between
+  two characters of one subline carries the ordinary amount, and a member's advance is the
+  step that reaches the member after it). The same reading closes §3.8.3's half of it: a
+  boundary the line was not composed from is not one the line may take space back from, so
+  the reduction ladder no longer reaches inside a block — the expansion ladder already did
+  not. No public API and no other engine changed. `engines/ocaml/probe/census.ml` reaches
+  both shapes at every class pair now: five further `constructs` variants
+  (`warichu-full-size` and its vertical mirror, `warichu-pair-inside`,
+  `warichu-pair-inside-row` and `warichu-pair-inside-justified`) and two further `tabs`
+  variants (a sign inside a note set at the paragraph's own em, at a stop the line reaches
+  and at one it has passed) — so the `constructs` census is 18,515 requests, `tabs` is
+  31,211, and all ten censuses are at zero differences across the three engines over
+  120,612. A sixth `constructs` variant is deliberately absent: a line that has to *give
+  space back* beside a note whose two sublines meet at a Table 1 amount is a coordinate the
+  Rust and OCaml engines do not yet agree on themselves — the Rust engine divides the
+  line's arrears over that in-block boundary and lays nothing down there, the OCaml engine
+  does not offer it at all — and a census asks the settled question.
 - The Racket reference engine now reads §3.6.3's tab round the way
   `docs/decisions/tab-line-correspondence.md` publishes it, which closes
   [#19](https://github.com/P4suta/jlreq/issues/19) and lifts the census exclusion the entry

ROADMAP.md

@@ -44,7 +44,7 @@ conformance protocol, gated on a milestone sequence of its own
 advanced toward the built-in suite one disjoint milestone per pull request and now claims
 milestone 9, the last one: all eighty-nine cases answer bit for bit, so `just ocaml-gate`
 and `just conform-ocaml` are the same run and the required CI job holds the engine to the
-whole suite. Ten synthetic censuses agree with the Rust engine across 116,909 further
+whole suite. Ten synthetic censuses agree with the Rust engine across 120,612 further
 requests, and the twenty-six observable policies the exercise turned up — rules two engines
 must share to pass the same case, stated in no sentence of JLReq and no file under `docs/` —
 are listed in `engines/ocaml/README.md` and are candidates for `docs/decisions/`.

data/manifest.toml

@@ -11,7 +11,7 @@
 
 [[file]]
 path = "ROADMAP.md"
-sha256 = "e47ffe6ac5c189fa125b463981404643086f40bced7d6713fc85cc773bad3b5e"
+sha256 = "d804757056cc7509c09721c86427db5405febca50853971416a14c63035dc47d"
 
 [[file]]
 path = "crates/jlreq-conformance/protocol.schema.json"

docs/decisions/README.md

@@ -35,7 +35,7 @@ reaches it, where any does — so that a reader can reproduce the observation ra
 the claim.
 
 A *third* engine ([engines/racket/](../../engines/racket/README.md)) has since been brought
-to zero differences against both of the others on all ten censuses, 116,909 requests, and
+to zero differences against both of the others on all ten censuses, 120,612 requests, and
 that convergence turned up nine more policies of the same kind. Two of them are subjects
 nothing here covered and have files of their own in the table below; the other seven belong
 to subjects already published and were written into those files, one of them into a reading

docs/decisions/jidori-room-and-solid-boundaries.md

@@ -11,7 +11,7 @@ SPDX-License-Identifier: MIT OR Apache-2.0
   [`engines/racket/structure.rkt`](../../engines/racket/structure.rkt)
 - Standing: `Unstated`
 - JLReq: §3.7.3, §B.1, §C.3, §3.8.3
-- Observed by: `just census tabs` (30,153 requests) and `just census constructs` (15,870
+- Observed by: `just census tabs` (31,211 requests) and `just census constructs` (18,515
   requests), the jidori variants; no built-in case reaches a jidori with no open boundary
 
 ## The silence

docs/decisions/ornamented-complex-geometry.md

@@ -11,7 +11,7 @@ SPDX-License-Identifier: MIT OR Apache-2.0
   [`engines/ocaml/lib/pipeline.ml`](../../engines/ocaml/lib/pipeline.ml)
 - Standing: `Unstated`
 - JLReq: §3.3.9, §3.7.1, §B.2#9, §C.2#6, §E.2#5
-- Observed by: `just census constructs` (15,870 requests), the emphasis and script variants
+- Observed by: `just census constructs` (18,515 requests), the emphasis and script variants
 
 ## The silence
 

docs/decisions/ruby-overhang-permission.md

@@ -150,7 +150,7 @@ is the one under which the sentence is about something.
 
 **Nothing before M6 could see this.** cl-09 and cl-10 are the same row and the same column in
 all six matrices, at every coordinate except those four ruby cells. An engine could carry
-either reading through 116,909 census requests and every one of the eighty-nine conformance
+either reading through 120,612 census requests and every one of the eighty-nine conformance
 cases without the difference surfacing anywhere but here. That is the reason to publish it
 rather than leave it in a comment: it is invisible until it is not, and the next independent
 engine has no way to derive it.

docs/decisions/stacked-structure-geometry.md

@@ -11,9 +11,10 @@ SPDX-License-Identifier: MIT OR Apache-2.0
   [`engines/ocaml/lib/pipeline.ml`](../../engines/ocaml/lib/pipeline.ml)
 - Standing: `Unstated`
 - JLReq: §3.4.2, §3.4.3, §3.7.2, §B.2#13, §C.3
-- Observed by: `just census constructs` (15,870 requests), the warichu and furawake
+- Observed by: `just census constructs` (18,515 requests), the warichu and furawake
   variants; the last two readings below by the third engine's convergence on the same
-  census
+  census, and the two block-axis and in-block readings by its `warichu-full-size` and
+  `warichu-pair-inside` variants
 
 ## The silence
 
@@ -84,6 +85,21 @@ stands before the whole block and is no part of the bracket's reported advance,
 amount stated in the *neighbor's* em is the neighbor's and stands where the neighbor puts
 it. A structure has two edges and they are the same edge twice.
 
+**The block a structure makes is not a depth the line reports.** A warichu's sublines run
+*beside* the line, so however deep they come to, the line's own block extent is the one the
+paragraph set — a note whose members are set at the paragraph's own em rather than at the
+half em §3.4.2's own sizing comes to makes a block two ems deep and leaves the line one em
+deep. The sublines' own extents are the block's business and the line reports its own.
+
+**A character *inside* the block is spaced like any other, and its advance is the step that
+reaches the next one.** §3.4.2's note is ordinary text of the note, so the boundary between
+two characters of one subline carries Table 1's ordinary amount, and the advance the
+character before it reports is its own body plus that amount — exactly what it would report
+standing beside the line. The character that *ends* a subline reports its body alone,
+because nothing of that subline stands after it. Neither ladder reaches such a boundary:
+§3.8.3 and §3.8.4 adjust the spacing of the line, and space inside a block was never the
+line's to give back or to open.
+
 **§3.4.3's balance is a demerit in the paragraph's own objective, ranked below an overrun
 and above a short line.** A break inside a warichu carries a cost proportional to how
 unevenly it divides the note — one 1,000,000-unit demerit per cluster of imbalance, in the
@@ -134,6 +150,28 @@ taken from — the same distinction [ruby-overhang-permission](ruby-overhang-per
 draws for a Table 1 `hang` term — and it is drawn once for the structure rather than twice
 for its brackets.
 
+**The block axis is the same sentence read across the line instead of along it.** "One
+position" is a statement about how much of the line a structure is, and a line has two
+extents. If the sublines' own heights summed into the line's, a caller could make a line
+taller by writing a longer note into it — and §3.4.2's own subject is a note set *inside* a
+line rather than one that pushes the lines apart. The sublines are not lines of their own,
+so what they cover is not a height the line has to make room for, exactly as their combined
+width is not a width the line advances by. It is the same argument that keeps the closing
+bracket's trailing space off the bracket, applied to the axis the section never spells out
+separately.
+
+**Inside the block, there is no structure to be at the edge of.** The two readings above
+withdraw a space because the character stands where the *line* stops and the block begins;
+between two characters of one subline there is no such edge, and the note is text being set.
+Table 1 is what sets text, so it answers there like anywhere else, and an engine that
+withheld it would be composing the note by a rule the specification states for nothing. The
+advance follows from the same place the line's own advances do: the number an implementation
+reports as a character's advance is the number that reaches the character after it, and an
+answer whose advances did not add up to its own positions would be two geometries at once —
+the defect [#24](https://github.com/P4suta/jlreq/issues/24) records. The ladders are the
+other half of it: a boundary the line was not composed from is not a boundary the line can
+adjust, which is why the two of them read the *line's* geometry and stop at the block.
+
 **A figure is an example, and an example cannot outrank the measure.** §3.4.3 shows what a
 straddling note looks like when it comes out well. Reading its balance as a *requirement*
 would put a rule about a note's own two lines above the rule that a line of base text fits
@@ -166,6 +204,13 @@ where it belongs, because it is a fact about how the matrix is addressed rather
 what a warichu is. That same legend settles the fourth reading in the same stroke: the two
 edges are one question and a note about either of them answers both.
 
+A sentence in §3.4.2 stating how deep a line carrying a note is, or an Appendix B legend
+that says whether the matrix is asked between two characters of one subline, settles the two
+readings above in the same stroke: both are questions about which object a rule is addressed
+to, and both were reached by measurement before anything was written down here
+([#23](https://github.com/P4suta/jlreq/issues/23),
+[#24](https://github.com/P4suta/jlreq/issues/24)).
+
 For the fifth, a sentence in §3.4.3 that states what its figures show as a rule — how much
 of a note goes on the first base-text line, and what yields to what when a division that
 balances the note costs the line something — settles it. Any weighting is publishable, and

docs/decisions/tab-line-correspondence.md

@@ -13,7 +13,7 @@ SPDX-License-Identifier: MIT OR Apache-2.0
   [`engines/racket/compose.rkt`](../../engines/racket/compose.rkt)
 - Standing: `Unstated`
 - JLReq: §3.6.1, §3.6.2, §3.6.3, §3.1 (silence), ADR-0018
-- Observed by: `just census tabs` (30,153 requests), and by probing the reference engine
+- Observed by: `just census tabs` (31,211 requests), and by probing the reference engine
   with stops the eighty-nine built-in cases never state; the reading about which constructs
   hold a coordinate a stop can name by the third engine's convergence on the same census.
   The two coordinates this file once excluded — a sign that opens a tate-chu-yoko run
@@ -215,7 +215,7 @@ tate-chu-yoko run; a sign inside a warichu and inside a furawake; a sign that op
 those; and a sign of the line standing *after* such a structure, whose own stop has to be
 measured from a walk in which the whole block is one step. Every one of them at both a stop
 the line has gone past and one it has not, and all three reference engines answer all of them
-alike at every class pair (30,153 requests, no difference). The last four shapes went in when
+alike at every class pair (31,211 requests, no difference). The last four shapes went in when
 the Racket engine reached the reading published here
 ([#19](https://github.com/P4suta/jlreq/issues/19)); until then they were deliberately left
 out, because a census is a gate and a gate that is red is not one.

docs/decisions/tate-chu-yoko-spacing-sources.md

@@ -15,7 +15,7 @@ SPDX-License-Identifier: MIT OR Apache-2.0
   sentence reaches at all.
 - JLReq: §3.2.5, §3.6, §B.1, §B.2, §3.8.3, §3.8.4
 - Observed by: `just census tate-chu-yoko` (4,761 requests) for the cl-30 coordinates, and
-  `just census tabs` (30,153 requests) for the cell after a tab sign
+  `just census tabs` (31,211 requests) for the cell after a tab sign
 
 ## The silence
 

docs/decisions/warichu-bracket-listing.md

@@ -11,7 +11,7 @@ SPDX-License-Identifier: MIT OR Apache-2.0
   [`engines/racket/classes.rkt`](../../engines/racket/classes.rkt)
 - Standing: `Unstated`
 - JLReq: §3.9.2, §3.4.2, §A.01, §A.02, §A.28, §A.29
-- Observed by: `just census constructs` (15,870 requests), the warichu variants
+- Observed by: `just census constructs` (18,515 requests), the warichu variants
 
 ## The silence