chappi-syntax

chappi-syntax provides Chappi v1's span-carrying generic S-expression parser, deterministic canonical serializer, and canonical SHA-256 hashing.

The parser accepts at most 256 nested lists and reports structured diagnostics for invalid input. Canonical output is UTF-8, NFC-normalized, LF-only, ordered, and, for a non-empty Document, terminated by exactly one newline. An empty Document canonicalizes to empty bytes. Valid snapshots contain a header, so their canonical output is always non-empty and newline-terminated.

The public API includes parse_document, canonicalize, canonical_hash, Document, Form, Atom, Span, and Diagnostic. API documentation is available on docs.rs.

Chappi stores explicit resumable semantic state; it is not a format for hidden chain-of-thought.