1.4.0

packTab 1.4.0 focuses on better sparse-prefix compression, clearer compression modes, and simpler generation logic.

Highlights

• Added explicit compression endpoints.
  • --compression 0 now selects a flat / unsplit encoding.
  • --compression 10 now minimizes raw table bytes.
  • --compression 1..9 keep the historical heuristic behavior.
• Added aligned leading-default culling.
  • Tables with large power-of-two-aligned default prefixes can now be rebased to the smallest dyadic interval covering the live range.
  • This preserves the recursive split structure while avoiding storage for removable all-default left branches.
• Added exact leading-default culling for inlineable spans.
  • When trimming to the first non-default index makes the remaining flat span small enough to inline as a constant, packTab now tries that exact rebase too.
• Removed the identity optimization.
  • This simplifies the model and code generation, and makes rebased sparse-prefix handling easier to reason about.
• Improved generated C and Rust lookups for rebased spans.
  • Rebased lookups use a single unsigned range check, including safe wrapping arithmetic on Rust.

Other changes

• Updated documentation for the new compression semantics and sparse-prefix behavior.
• Expanded tests for compression endpoint selection, aligned prefix culling, and exact-inline prefix culling.

Validation

• Full test suite passes: 204 tests.