Reference

Public API

item	what it is
Eval	zero-sized operation marker that namespaces the eval stage
EvalRequest	the AST + language + context an engine is asked to evaluate
EvalEngine	the trait an eval engine implements
JOURNAL_FRAME_KEY, RESUME_KEY, HANDLER_ACC_KEY	value keys carrying resumable-handler state (ADR-0158)
Num, OpService	numeric helpers and the operation-dispatch service
apply_native_op, apply_handler_impl	the shared dispatch path both engines use

Crate

crate	role
hnl-engine-exec	abstraction — contract only

Build and test

cargo build     # sibling [patch] tables resolve deps from ../<repo>
cargo test      # no test suite here — covered by consumers

Dependencies are git deps on branch = "main"; locally the [patch] tables point at sibling checkouts (regenerated by host/scripts/dev-link.sh).