Architecture Decision Records

Key design decisions behind ArchLang, with their context and trade-offs.

• 1. Hand-written recursive-descent parser, not Lezer/tree-sitter
• 2. Optional, lazy-loaded dependencies for heavy geometry and raster
• 3. Expand-time scripting — no runtime, no I/O, no clock
• 4. Relational placement is deterministic arithmetic, not an optimizer
• 5. Design intelligence is facts + advisory lint, not an invisible architect
• 6. A solver is an explicit source transform, never invisible render behavior
• 7. Editor metadata (data-span) enters SVG output only opt-in
• 8. Circulation is reported as facts on a clearance-eroded nav grid, never generated
• 9. AI-first: one bundled context artifact, opt-in error rendering, distribution over protocol
• 10. "The Compile Boundary" — one two-world design system for both public sites
• 11. Machine-applicable fixes: the rustc model, kept distinct from the geometric repairer
• 12. An MCP shim as a discoverability channel — amending "distribution over protocol"
• 13. A versioned, fully synthetic, self-verifying repair-trajectory dataset
• 14. One light world — no dark mode, no dark surfaces, on either public site
• 15. The CLI is an agent interface: one manifest, filters that never gate, loud misuse
• Component instances are resolved in their own frame, then transformed
• 17. Fixture semantics: three distinct flags, one shared predicate, one derived table
• 18. One zero-dependency joinery pass for every wall
• 19. Both public sites on Cloudflare Workers static assets, deployed from CI