pub enum Extent {
Region,
OnePiece,
Unstated,
}Expand description
What declares how big this campaign’s map is — asked once, by both tiers that need the answer.
A horizon that BUILDS terrain has to ring a stated extent, and whether one is
stated is a fact about the documents: validation refuses DW0855 on it
before a block is placed, and the compiler derives the rectangle from the
same answer. Two implementations of one predicate is two verdicts waiting to
disagree — the tiers already disagreed once about which arm of DW0855’s own
message applied — so the predicate lives here and the rectangle is derived
from the authority this names.
Variants§
Region
The site plan’s region: the whole map’s design of record, the
brief’s number flowing down. A box outside it is DW0826, so nothing a
part does can grow it.
OnePiece
The one piece’s own declared region: the campaign is one area bound
to one prefab, so its whole map is that piece and the piece’s declared
structure size is the map’s extent. This is what a site is — a building
with its island, its moat and its banks inside one box — and the
declaration is the prefab document’s, held to the .nbt by DW0888.
Unstated
Nothing states one. Two or more areas, or one area drawing from a
pool, or no area at all: the only candidate left is the union of what
happens to get placed, which DW0855 refuses because areas sit on the
compiler’s fixed stride and a pool’s footprint is the solver’s answer.