Chez Phase 1 (increment 3f): quoted literals

Emit a :quote node by reconstructing the raw reader form as RT constructor
calls: symbol -> jolt-symbol, list (array) -> jolt-list, vector (tuple) ->
jolt-vector, map -> jolt-hash-map, set -> jolt-hash-set, scalars via emit-const.
The runtime value of a quote is just that literal data (the interpreter returns
the reader form verbatim).

Quote exposed a latent seq.ss bug: empty map/filter results were jolt-nil, but
Clojure's (map f []) is an empty seq, so (= () (map f [])) must be true. Return
jolt-empty-list (which seqs back to nil, so it's still a valid lazy-tail
terminator) instead — matching jolt-take/drop/rest/list.

Prelude emit reach 334 -> 342/355. Subset probe 632 -> 664/664 compiled, 0
divergences (quote + the seq fix pull 32 corpus cases into the subset). emit-test
110/110 (added 16 quote cases). corpus.edn regenerated (the 3 malformed-catch
spec rows). Full gate green.

host/chez/emit.janet

@@ -138,6 +138,35 @@
     (string "(integer->char " (get v :ch) ")")
     (errorf "emit-const: unsupported literal %p" v)))
 
+# Quoted literals (jolt-u8j7). A :quote node's :form is the RAW reader form (a
+# Janet value): scalars are Janet natives, a symbol is {:jolt/type :symbol …}, a
+# list is an array, a vector a tuple, a map a struct/phm, a set a tagged struct.
+# Reconstruct each as the matching Chez RT constructor — the runtime value of a
+# quote is just that literal data (the interpreter returns the reader form
+# verbatim; the Janet backend Janet-quotes it; here we rebuild it on the RT).
+(var emit-quoted nil)
+(defn- emit-quoted-map [m]
+  (def flat @[])
+  (eachp [k v] m (array/push flat (emit-quoted k)) (array/push flat (emit-quoted v)))
+  (string "(jolt-hash-map " (string/join flat " ") ")"))
+(set emit-quoted (fn emit-quoted [form]
+  (cond
+    # scalars emit-const already lowers (nil/bool/number/string/keyword/char)
+    (or (nil? form) (boolean? form) (number? form) (string? form) (keyword? form))
+    (emit-const form)
+    (and (struct? form) (= :symbol (get form :jolt/type)))
+    (let [ns (get form :ns)]
+      (string "(jolt-symbol " (if ns (string/format "%j" ns) "#f") " "
+              (string/format "%j" (get form :name)) ")"))
+    (and (struct? form) (= :jolt/char (get form :jolt/type))) (emit-const form)
+    (and (struct? form) (= :jolt/set (get form :jolt/type)))
+    (string "(jolt-hash-set " (string/join (map emit-quoted (get form :value)) " ") ")")
+    (array? form) (string "(jolt-list " (string/join (map emit-quoted form) " ") ")")
+    (tuple? form) (string "(jolt-vector " (string/join (map emit-quoted form) " ") ")")
+    (phm/phm? form) (emit-quoted-map (phm/phm-to-struct form))
+    (or (struct? form) (table? form)) (emit-quoted-map form)
+    (errorf "emit-quoted: unsupported quoted form %p" form))))
+
 (defn- emit-binding [b]
   (def b (vv b))
   (string "(" (munge (get b 0)) " " (emit (get b 1)) ")"))
@@ -331,6 +360,7 @@
     :recur (emit-recur node)
     :throw (string "(jolt-throw " (emit (get node :expr)) ")")
     :try   (emit-try node)
+    :quote (emit-quoted (get node :form))
     :fn    (emit-fn node)
     :def   (string "(def-var! " (string/format "%j" (get node :ns)) " "
                    (string/format "%j" (get node :name)) " " (emit (get node :init)) ")")

host/chez/seq.ss

@@ -107,11 +107,15 @@
 ;; map / filter / reduce / into / remove + range / take / concat / apply
 ;; ============================================================================
 (define (any-nil? seqs) (and (pair? seqs) (or (jolt-nil? (car seqs)) (any-nil? (cdr seqs)))))
+;; An EMPTY seq result is () (jolt-empty-list), NOT nil — Clojure's (map f []) is
+;; an empty seq, so (= () (map f [])) is true and (nil? (map f [])) is false.
+;; jolt-empty-list seqs back to nil, so it stays a valid lazy-tail terminator for
+;; the non-empty case (printing / seq= / reduce all walk via jolt-seq).
 (define (map-seq f s)
-  (if (jolt-nil? s) jolt-nil
+  (if (jolt-nil? s) jolt-empty-list
       (cseq-lazy (jolt-invoke f (seq-first s)) (lambda () (map-seq f (jolt-seq (seq-more s)))))))
 (define (map-seq* f seqs)              ; multi-collection map; stops at the shortest
-  (if (any-nil? seqs) jolt-nil
+  (if (any-nil? seqs) jolt-empty-list
       (cseq-lazy (apply jolt-invoke f (map seq-first seqs))
                  (lambda () (map-seq* f (map (lambda (s) (jolt-seq (seq-more s))) seqs))))))
 (define (jolt-map f . colls)
@@ -121,7 +125,7 @@
 
 (define (filter-seq pred s keep)
   (let loop ((s s))
-    (cond ((jolt-nil? s) jolt-nil)
+    (cond ((jolt-nil? s) jolt-empty-list)   ; empty result is () (see map-seq)
           ((eq? keep (jolt-truthy? (jolt-invoke pred (seq-first s))))
            (cseq-lazy (seq-first s) (lambda () (filter-seq pred (jolt-seq (seq-more s)) keep))))
           (else (loop (jolt-seq (seq-more s)))))))

test/chez/README.md

@@ -48,12 +48,13 @@ compile-time signal) and are counted "out of subset", not as divergences.
 
     JOLT_CHEZ_CORPUS=1 janet test/chez/run-corpus-chez.janet
 
-Baseline after inc 3e (throw/try + ex-info): **632/632 compiled cases pass**, 0
+Baseline after inc 3f (quoted literals): **664/664 compiled cases pass**, 0
-divergences; 2023/2655 out of subset (await clojure.core on Chez). Inc 3c
+divergences; 1994/2658 out of subset (await clojure.core on Chez). Inc 3e
-(multi-arity + variadic fns) brought this to 619/619 — `emit-fn` lowers
+(throw/try + ex-info) was 632/632; inc 3f's quote support + a seq.ss fix (empty
-multi-arity fns to a Scheme `case-lambda` and variadic fns to a rest-arg lambda
+`map`/`filter` results are `()` not nil, matching Clojure) pulled 32 more corpus
-(the Scheme rest list is coerced to a jolt seq, nil when empty); inc 3e's
+cases into the subset. `emit-fn` lowers multi-arity fns to a Scheme `case-lambda`
-throw/try/ex-info support pulled 13 more corpus cases into the subset.
+and variadic fns to a rest-arg lambda (rest list coerced to a jolt seq, nil when
+empty).
 
 ## Phase 1 — clojure.core prelude emission (inc 3d, jolt-ocvi)
 The `-e`-capable jolt-chez path: emit the clojure.core tiers
@@ -70,15 +71,16 @@ catalogs the gaps; macros are skipped (analyze-time only, not a runtime value):
 
     JOLT_CHEZ_PRELUDE=1 janet test/chez/core-prelude-probe.janet
 
-Baseline after inc 3e (throw/try + ex-info): **334/355 non-macro core forms emit**
+Baseline after inc 3f (quoted literals): **342/355 non-macro core forms emit** to
-to Scheme (was 303 at inc 3d). `:throw` lowers to `jolt-throw` (Scheme `raise` of
+Scheme (was 334 at inc 3e, 303 at inc 3d). A `:quote` node reconstructs the raw
-the raw jolt value, like the Janet compiled back end); `:try` lowers to `guard`
+reader form as RT constructor calls — symbol → `jolt-symbol`, list → `jolt-list`,
-(catch, class dropped → catch-all) + `dynamic-wind` (finally); `ex-info` is a
+vector → `jolt-vector`, map/set → `jolt-hash-map`/`jolt-hash-set`, scalars via
-native-op building the tagged jolt map, so the ex-data/ex-message/ex-cause tier
+`emit-const`. Prior: `:throw` → `jolt-throw` (Scheme `raise` of the raw jolt
-fns read it over `get` for free. Remaining 21 gaps: `:quote` (8, needs RT
+value); `:try` → `guard` (catch, class dropped → catch-all) + `dynamic-wind`
-symbols/lists), Java host interop `.write`/`.isDirectory` (6, io tier), `letfn`
+(finally); `ex-info` native-op building the tagged jolt map, so the tier
-(4), `declare`/def-no-init (2), one edge (`parse-uuid`). Each is a clean
+ex-data/ex-message/ex-cause read it over `get` for free. Remaining 13 gaps: Java
-next-increment target. The probe has a regression floor (raise it as gaps close).
+host interop `.write`/`.isDirectory` (6, io tier), `letfn` (4), `declare`/
+def-no-init (2), one edge (`parse-uuid`). The probe has a regression floor.
 
 Prior, inc 3b (seq tier + dynamic IFn, jolt-5pso): 595/595 compiled, 0 divergences,
 2060/2655 out of subset. The seq tier brought up a list/lazy-seq type with

test/chez/core-prelude-probe.janet

@@ -98,7 +98,7 @@
 
 # Regression floor (raise it as new IR ops / RT shims land, like the suite
 # baseline). Fails if prelude emit reach drops below the recorded baseline.
-(def reach-floor 334)
+(def reach-floor 342)
 (when (< compiled reach-floor)
   (printf "REGRESSION: prelude emit reach %d < floor %d" compiled reach-floor)
   (os/exit 1))

test/chez/corpus.edn

@@ -152,6 +152,9 @@
   {:suite "exceptions / try-catch" :label "finally runs on ok" :expected "2" :actual "(let [a (atom 0)] (try 2 (finally (reset! a 9))) )"}
   {:suite "exceptions / try-catch" :label "finally runs on throw" :expected "9" :actual "(let [a (atom 0)] (try (throw (ex-info \"x\" {})) (catch :default e nil) (finally (reset! a 9))) @a)"}
   {:suite "exceptions / try-catch" :label "catch value of body" :expected "5" :actual "(try (+ 2 3) (catch :default e 0))"}
+  {:suite "exceptions / try-catch" :label "malformed catch: non-symbol binding" :expected :throws :actual "(try 1 (catch e (* e 10)))"}
+  {:suite "exceptions / try-catch" :label "malformed catch: literal binding" :expected :throws :actual "(try 1 (catch e 5))"}
+  {:suite "exceptions / try-catch" :label "malformed catch: too short" :expected :throws :actual "(try 1 (catch Exception))"}
   {:suite "exceptions / assert" :label "assert true -> ok" :expected ":ok" :actual "(do (assert true) :ok)"}
   {:suite "exceptions / assert" :label "assert expr -> ok" :expected ":ok" :actual "(do (assert (= 1 1)) :ok)"}
   {:suite "exceptions / assert" :label "assert false throws" :expected :throws :actual "(assert false)"}

test/chez/emit-test.janet

@@ -236,6 +236,29 @@
   (ok "throw: uncaught exits non-zero" (not= code 0)
       (string "code=" code " out=" out)))
 
+# 3j) quoted literals (inc 3f): a :quote node reconstructs the reader form as RT
+#   values — symbols, lists, vectors, maps, sets, nested. Value parity vs the CLI.
+(each src ["'foo"
+           "'foo/bar"
+           "':kw"
+           "'(1 2 3)"
+           "'[1 2 3]"
+           "'(a b c)"
+           "'{:a 1}"
+           "'(1 (2 3) 4)"
+           "(first '(10 20 30))"
+           "(count '[1 2 3])"
+           "(rest '(1 2 3))"
+           "(= 'foo 'foo)"
+           "(= 'a 'b)"
+           "(map inc '(1 2 3))"
+           "(conj '[1 2] 3)"
+           "(get '{:a 7} :a)"]
+  (let [[code out err] (d/run-on-chez ctx src)
+        want (cli-oracle src)]
+    (ok (string "quote: " src) (and (= code 0) (= out want))
+        (string "chez=" out " janet=" want " | " err))))
+
 # 3h) prelude mode (inc 3d): emitting clojure.core ITSELF, a core->core ref must
 #   lower to a runtime var-deref instead of being rejected as "out of subset".
 #   `frequencies` is a core fn but not a native-op, so it exercises the switch.