Extending attributes
There are two ways to give meaning: a large class hierarchy, or a few interpreted words plus an open vocabulary. koyu takes the second. Extension is adding a word, not revising a schema, and that is where connections to outside classification systems — city data, property identifiers, sensors, network data — can land.
But the openness has a shape. Being open and being trustworthy are compatible provided the boundary is declared. Without that declaration you cannot tell "not looked at" from "looked at and fine". An "all clear" in that state means nothing.
Types are free words
The second positional argument of space (the type) is required, but any value passes.
grid X 0 2000
grid Y 0 2000
level L1 0 h:2400 slab:150
space /L1/a wumbo X1..X2 Y1..Y2✔ Consistent — 1 space / 0 boundaries
Structural consistency only — architectural validity is what koyu validate says, separatelyThe bundled examples actually use 32 distinct types across 469 space lines. By frequency: shop (85), corridor (66), room (41), shaft (39), exterior (34), service (33), unit (20), stair (19), hall (15), and so on. That is de facto usage, not a ledger and not a contract.
The two words that are not open
Of all types, exactly two are read structurally by the tools.
| Type | Interpretation |
|---|---|
exterior | the exterior; may have no region. Add road: and it counts towards frontage |
void | a void; excluded from floor area, not passable |
Every other type, however meaningful it looks, is a free word as far as the tools are concerned. stair, shaft and ldk are not interpreted as space types.
And these two words alone have their spelling protected.
✖ near.muro:line 5: The type exteriorr looks like a misspelling of exterior (exterior is read structurally — if a different word was meant, spell it further away)If exteriorr passed silently, that space would stop being the exterior and the gross floor area would double. The cost of a one-character slip is too high, so near misses — and only near misses — are refused. Distant words (room, yard, wumbo) draw no comment.
Attributes come in three tiers
| Tier | Examples | What core does |
|---|---|---|
| structural | path, type, region, level, the other end of a relation, kind | always read. If it is broken, nothing is read |
| interpreted | h, w, at, edge, daylight, road, site, style … | the ledger defines the value range, and it is read |
| carried | acme.sensor, bems.temp, survey.measured … | not read. Open, with a namespace |
The carried tier takes a dot-separated namespace.
grid X 0 2000
grid Y 0 2000
level L1 0 h:2400 slab:150
space /L1/a room X1..X2 Y1..Y2 name:居間 acme.sensor:23 bems.temp:22.5✔ Consistent — 1 space / 0 boundaries
Structural consistency only — architectural validity is what koyu validate says, separatelycore gives acme.sensor and bems.temp no meaning whatsoever — it does not check their range and uses them in neither derivation nor judgement. Write anything.
An unknown key without a namespace is an error.
grid X 0 2000
grid Y 0 2000
level L1 0 h:2400 slab:150
space /L1/a room X1..X2 Y1..Y2 nmae:居間✖ att.muro:line 5: /L1/a carries nmae:, which is not in the ledger (check the spelling, or add a namespace if the value is only carried — e.g. acme.nmae:居間)This used to pass silently. The reasoning was that a word not in the ledger is not wrong, merely uninterpreted, so it went straight into the canonical JSON. The reasoning was consistent and the price was too high — by the same reasoning heigh:2400 silenced the height invariant check, sit:1 silenced site judgement, and stiar:N silenced vertical circulation entirely, all of them staying green.
The namespace is how that boundary is spelled. Carrying without judging is a legitimate state, and saying so explicitly is the condition of the freedom. The attribute ledger is Attributes; the error is detailed in ATT.
Judgement is entered by declaration, not by type
Where free types pay off is in seeing where judgement is entered.
To bring a windowless bathroom into daylight scope, do not change the type — write daylight:1.
grid X 0 2000
grid Y 0 2000
level L1 0 h:2400 slab:150
space /L1/bath wet X1..X2 Y1..Y2 name:浴室 daylight:1
space /out exterior
boundary /L1/bath /out edge:S t:150✖ /L1/bath 浴室 window 0.00 m2 / floor 4.00 m2 = no window (needs 1/7 ≈ 0.57 m2)
✖ Short of 1/7: 1 of 1 room (this is a validation judgement)Change the type from wet to bedroom and nothing about the judgement moves. Whether a judgement applies is something the author declares; it is not inferred from a room's name.
This matches practice. Under Japan's Building Standards Act a habitable room is decided by how the room is actually used, not by its label. Note also that the attribute names a behaviour of the tool, not the legal concept — the two are not the same set.
The discipline for adding words
An open vocabulary does not mean anything may be added. Five questions settle whether a word or feature is adopted.
- Does it have substance? If so it takes a seat on a relation or on the given. It does not go on a space.
- Is it given? Coordinates that are not given are not written.
- Can several opinions exist at the same seat? If so it goes onto composition's set editing. No bespoke syntax.
- Is it a judgement? Then it belongs to the validation surface, not to the notation.
- Is it form? Then it belongs to the drawing surface, not to the notation.
"Would this let real architecture be written?" is not one of the tests. No decision is recorded with the reservation "we will decide if a real example demands it". A reservation is an entrance for expansion.