Add boundary.sx declaring all 34 I/O primitives, 32 page helpers, and 9
allowed boundary types. Runtime validation in boundary.py checks every
registration against the spec — undeclared primitives/helpers crash at
startup with SX_BOUNDARY_STRICT=1 (now set in both dev and prod).
Key changes:
- Move 5 I/O-in-disguise primitives (app-url, asset-url, config,
jinja-global, relations-from) from primitives.py to primitives_io.py
- Remove duplicate url-for/route-prefix from primitives.py (already in IO)
- Fix parse-datetime to return ISO string instead of raw datetime
- Add datetime→isoformat conversion in _convert_result at the edge
- Wrap page helper return values with boundary type validation
- Replace all SxExpr(f"...") patterns with sx_call() or _sx_fragment()
- Add assert declaration to primitives.sx
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Meta-circular evaluator: the SX language specifying its own semantics.
A thin bootstrap compiler per target (JS, Python, Rust) reads these
.sx files and emits a native evaluator.
Files:
- eval.sx: Core evaluator — type dispatch, special forms, TCO trampoline,
lambda/component/macro invocation, higher-order forms
- primitives.sx: Declarative specification of ~80 built-in pure functions
- render.sx: Three rendering modes (DOM, HTML string, SX wire format)
- parser.sx: Tokenizer, parser, and serializer specification
Platform-specific concerns (DOM ops, async I/O, HTML emission) are
declared as interfaces that each target implements.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>