9. Components, Editing, and Multi-building

9.1 def (components)

def defines a slot-bearing Component, unified with theme and site by the same mechanism. This keeps the reference system from fracturing across editing, theming, and multi-building connection.

• Parameterization (variable size, etc.) is allowed. Recursion is forbidden.
• A def may declare requires version>=X; the minimum version of a composite is the max of its parts (Versioning and Editions).

def cottage class=house size=9x7:
  floor  id=floor mat_slot=floor
  walls  id=walls class=outer mat_slot=wall height=4
  door   id=door  class=entry side=front at=center
  roof   id=roof  kind=gable mat_slot=roof

9.2 Editing model

Explicit IDs + auto stable addresses, combined. Important members carry id=; unspecified members get a meaning-based stable address auto-assigned by the compiler. Addresses derive from parent / role / side / level / offset rather than generation order, so they stay stable under appends.

Edits are patch DSL against a selector/address:

edit window[class=vent][level=floor2] set shape=arch
edit window@front[0]                  set mat_slot=accent_glass
edit door[id=entry]                   set side=front at=center

Editing at the level of a concept (“make only the second-floor windows arched”) must be possible without breaking the whole. Edit diffs look only at intent_state (Blockstate Model), so a change in derived results does not harm edit stability.

9.3 Multi-building (site)

Do not make the AI do absolute-coordinate arithmetic. Place via topological relational constraints; resolving to absolute coordinates is the compiler’s responsibility.

site village:
  place id=home1 use=cottage theme=medieval at=origin
  place id=home2 use=cottage theme=medieval east_of=home1 gap=4
  connect home1.door to home2.door path=@gravel

Each struct exposes ports (position / normal / width), and connect joins them. Villages and castles that exceed the structure block’s 48³ limit are expressed as the composition of multiple structs.