Native functions (NativeFn/VmClosure) called through the CEK evaluator
can now have their Eval_errors caught by guard/handler-bind. The fix is
at the exact OCaml↔CEK boundary in continue-with-call:
- sx_runtime.ml: sx_apply_cek wraps native calls, returns error marker
dict {__eval_error__: true, message: "..."} instead of raising
- sx_runtime.ml: is_eval_error predicate checks for the marker
- spec/evaluator.sx: continue-with-call callable branch uses apply-cek,
detects error markers, converts to raise-eval CEK state
- transpiler.sx: apply-cek and eval-error? emit cases added
No mutable flags, no re-entry risk. Errors flow through the CEK handler
chain naturally. 2798/2800 tests pass.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
giles
1d68f20a37