Emit :throw as jolt-throw (Scheme raise of the raw jolt value, matching the
Janet compiled back end's (error v) — no envelope, so catch binds it directly).
Emit :try as guard (catch; the class is dropped in the IR, so it's catch-all)
plus dynamic-wind for finally. ex-info is a native-op building the tagged jolt
map {:jolt/type :jolt/ex-info :message :data :cause}, so the ex-data/ex-message/
ex-cause tier fns read it over jolt-get for free.
Prelude emit reach 303 -> 334/355 (:throw and :try gaps close). Subset probe
619 -> 632/632 compiled, 0 divergences (throw/try/ex-info pull 13 corpus cases
into the subset). emit-test 94/94 (added 11 throw/try/ex-info cases + uncaught
exits non-zero). Full gate green.
Add a prelude emit mode to host/chez/emit.janet: when emitting clojure.core
itself (not user -e), a non-native clojure.core ref lowers to a runtime
var-deref instead of being rejected as out-of-subset, so core fns chain
through each other. Default (subset) mode is unchanged — the corpus probe
still rejects unimplemented core refs for a clean signal.
core-prelude-probe.janet walks the tiers through the live analyzer->emit
pipeline and catalogs reach + gaps (macros skipped; analyze-time only).
Baseline: 303/355 non-macro core forms emit. Remaining gaps are a tight
punch-list for the next increments: :throw (29), :quote (8), :try (2), Java
host interop (6), letfn (4), declare (2). Probe has a regression floor.
emit-test 83/83 (added prelude-mode lowering assertions); subset probe
619/619 unchanged; full gate green.
