Module start 

Structure starts and references.

Structs

StructureReferenceSet

Set of structure-start chunk positions with vanilla iteration order.

StructureStart

A structure start placed in a chunk. Vanilla’s StructureStart — invalid (empty) starts are not stored.

Type Aliases

StructureReferenceMap

Structure references → origin chunk positions.

StructureStartMap

Structure starts keyed by structure id.