Recorded while building the seat detector. A capability is a named fact about a
machine: its presence gates an assignment and its detail can carry a value, so
"can this run here" and "what should it be configured as" are the same fact
read two ways. A verdict has always had a detail beside its yes or no, so
panel: oled needs no new concept.
Two things that keep the set honest, both worth writing down before anyone adds
the fiftieth capability. It must be detected and the detector must say how it
knows -- so nobody can add one they cannot check, which is the whole of issue
007. And detectors ship inside the host, which is one static binary, so adding
a capability means shipping a new host everywhere. That argues for a small
general vocabulary rather than a specific one.
Three decisions, all Jochen's, and the first is the one that unlocked it.
Exclusivity is not a property of a module. It is a property of a singular
resource the module takes over. Two shells compete for nothing and any number
may be installed; two display servers both want the seat. So a module declares
what it CLAIMS, and two modules claiming the same thing cannot both be assigned
within that claim's scope.
Not "xorg conflicts with wayland". Pairwise exclusion has a property that only
shows up later: adding a third display server means editing xorg and wayland to
know about it. Every new module requires changing modules nobody who wrote it
owns, and the edits grow as the square of the count. With a claim the third one
says what it claims and nothing else changes anywhere.
Claims have a scope -- node, site, mesh -- which is not new. The mesh already
enforces exactly one hub with a unique index. Scope is that idea said once
rather than hard-coded per case.
And some conflicts need no claim at all: two modules declaring the same file or
binding the same port are visible from what they declare. A claim is only
written for the abstract ones.
A requirement with several answers is refused, never guessed. One candidate is
assigned silently because there was no choice to make; none is refused naming
what is missing; several is refused naming them. That is what makes a solver
unnecessary -- counting candidates has no surprising behaviour, and a solver
can be added later without changing a single manifest.
Flavor is retired. It was carrying three unrelated meanings: variants of a
thing, a subset of a module a node installs, and whatever the current system
does, which earned two knowledge-base entries about going wrong. A word with
three meanings cannot be reasoned about. What it reached for is two ordinary
things -- different modules providing the same thing, and one module with a
setting.
Decided after measuring what renumbering actually costs: 96 references in code
comments across two repositories, none of which would have failed to compile.
They would have pointed at the wrong reasoning, which is worse than a broken
link because nothing reports it.
So a number identifies a record and never changes. It cannot also be a
position -- a position moves when the set changes, and an identity that moves
is not one.
The reading order moves into an index generated from each record's `topic:`.
Six topics, in the order somebody learns the system.
The index is WRITTEN rather than only generated on demand, which reverses what
this repository previously said. The reason it said otherwise is that a
hand-written index drifts -- but a reader looking at the folder on a forge sees
the folder, not a command, and the drift objection is answered by checking
rather than by refusing to write one. That is §5's own rule: a rule states how
it is checked.
Two checks, both confirmed to bite. index.py fails when the written order no
longer matches the records. records.py fails when a record has no topic or one
nobody defined -- the quiet failure being a record that vanishes from the order
rather than appearing in the wrong place.
Jochen asked whether the order made sense. It did not -- it followed when
things happened to be decided, which after consolidation is fictional anyway
since record 5 alone folds decisions taken across a week.
Concretely wrong before: the domain statement sat at 8, after five engineering
rules; the constitution was scattered across 5, 12 and 17; the tiers landed at
15, 16, 21 and 22 with process records in between.
Now it walks: what the mesh is (1-3), its tiers from the bottom up (4-8), what
runs on them and how it gets there (9-10), how it is built (11-16), how it is
checked (17-18), how we work (19-23).
Two things made this safe rather than free. It is a permutation, not a
compaction, so the renames go through temporary names -- otherwise two files
want one slot and one is lost. And the reference rewrite is a single
simultaneous pass, because almost every number moved into a slot another number
was vacating; replacing one at a time would have cascaded and pointed things at
the wrong record while still resolving.
Verified: 284 [ADR NNNN](path) links across the repository, all with matching
text and target.
The ordering principle is now stated in 19 rather than left implicit -- the
repository already said "the numbering is the flow" about its folders, and
there was no reason for the records to be the exception.
jschoubben