Design

These chapters record the intended seams and ownership rules behind sigil-stitch. They complement the architecture overview, which explains how data flows through the implementation.

• Declaration Specs and Language Lowering defines the distinction between declaration intent, semantic capabilities, target-language grammar, structured source blocks, and final rendering.
• TypeName Validation and Lowering defines the fallible language-owned seam that materializes semantic TypeName values before import collection.
• Language-Aware Tokenizer describes the private typed pipeline used by sigil_quote!.

Design chapters describe the accepted 0.7 built-in architecture. Declaration lowering, type-name lowering, and complete-set import resolution are implemented. Frozen 0.6.8 compatibility lowerers remain for external adapters and legacy direct facades; each chapter points to the compatibility appendix where that boundary matters.

These chapters document the selected design and its invariants, not a catalogue of every rejected alternative. When the history of a hard-to-reverse trade-off is important, it belongs in a focused record under docs/adr/.