Skip to content
Cairn

15. Open Issues

15.1 Design choices to settle at implementation time

Section titled “15.1 Design choices to settle at implementation time”
  • Where provenance lives: .crn header vs lock. The tentative policy is “the .crn carries only @intended_targets (a hint); records such as verified are written into the lock by the compiler” (Versioning and Editions).
  • The type of the reverse-direction IR: a single degenerate-able IR, or separate Intent IR and Raw Geometry IR types. The tentative policy is “share the block-array layer; split types at the member layer above it” (Architecture).
  • Legacy .schematic (pre-1.13): unsupported in v1. A numeric-ID mapping could be considered later as an option.

15.2 Untouched topics

Section titled “15.2 Untouched topics”
  • Coordinate system: keep corner origin + front=+z fixed, or introduce a center origin / an entrance-relative orientation / a per-floor local y=0 (level id=floor2 y=4).
  • Primitive promotion: whether to promote hip/flat/pyramid roofs, column, arch, repeat, etc. to semantic primitives. The decision is based on experimental data from the evaluation framework (Evaluation Framework).
  • Interiors: whether the inside.front prefix suffices or a room higher-level concept should be introduced; whether furniture can be served by a def library.

15.3 Language-evolution policy (date-based versioning)

Section titled “15.3 Language-evolution policy (date-based versioning)”

How to handle breaking changes as Cairn evolves is not yet settled: a Rust-style “edition” mechanism (year-based opt-in) or simply announcing changes per release in the CHANGELOG. Note that the word “edition” is already used for Java/Bedrock, so a different term would be needed. For now the latter (CalVer + @cairn provenance) suffices.