Errors, Warnings, and Diagnostics

At a glance

(guard (e (else (error-object-message e))) (car 1))

Result

"car: expected a pair, got 1"

Current guarantees

• Runtime errors use E3xx codes, stable templates, deterministic irritant rendering, and the enclosing call-site span.
• Warnings are ordered observations; deprecated %, list-first, and list-rest emit their pinned W3xx warnings.
• The first uncaught error aborts without a host stack trace; resource exhaustion remains outside catchable E3xx.

Boundaries

• A warning is not stdout and must not be reordered or merged into a diagnostic.
• Platform panic, blank crash, and nondeterministic host text are not valid guest diagnostics.