feat(repl): add clojure.repl/stack-element-str over cljw frame maps

Smell-audited: 1: cljw has no StackTraceElement (ADR-0059) so it takes the cljw-native frame map; render string is duplicated with clojure.stacktrace/print-trace-element (both fixed by ADR-0140), kept inline + cross-referenced rather than adding a load-order-sensitive stacktrace->repl dep for a stable 1-line format.

stack-element-str was missing. cljw has only Clojure frames (ADR-0120), so it takes the cljw-native frame map {:ns :fn :file :line} (as returned by stack-trace) and renders <ns>/<fn> (<file>:<line>), exactly clj's Clojure-frame output (verified vs oracle: clojure.core/map (core.clj:2743)). placement.yaml regenerated; CHANGELOG [Unreleased] + repl_test.clj cover it.

Author: BuddhiLW

CHANGELOG.md

@@ -15,6 +15,12 @@ first stable `1.0.0` tag; pre-1.0 `alpha` / `rc` tags may still change surfaces.
   `(munge "foo-bar?")` is `"foo_bar_QMARK_"`. cljw carried `namespace-munge`
   and `demunge` but not the full `munge`; found while writing dev tooling.
 
+- **`clojure.repl/stack-element-str`.** Renders one stack frame as
+  `<ns>/<fn> (<file>:<line>)`. cljw has no JVM `StackTraceElement` and only
+  Clojure frames, so it takes the cljw-native frame map `{:ns :fn :file :line}`
+  (as returned by `stack-trace`) and produces exactly clj's Clojure-frame form,
+  e.g. `"clojure.core/map (core.clj:2743)"`.
+
 ### Fixed
 
 - **`clojure.repl/demunge` maps the `$` nested-class separator to `/`.**

data/placement.yaml

@@ -24,9 +24,9 @@
 schema_version: "2.0"
 summary:
   namespaces_required: 34
-  total: 1420
+  total: 1421
   zig: 405
-  clj: 794
+  clj: 795
   value: 215
   unbound: 6
 vars:
@@ -1039,6 +1039,7 @@ vars:
   "clojure.repl/root-cause": { impl: clj, flags: "-" }
   "clojure.repl/source": { impl: clj, flags: "macro" }
   "clojure.repl/source-fn": { impl: clj, flags: "-" }
+  "clojure.repl/stack-element-str": { impl: clj, flags: "-" }
   "clojure.set/difference": { impl: clj, flags: "-" }
   "clojure.set/index": { impl: clj, flags: "-" }
   "clojure.set/intersect2": { impl: clj, flags: "private" }

src/lang/clj/clojure/repl.clj

@@ -28,6 +28,19 @@
       (clojure.string/replace "$" "/")
       (clojure.string/replace "_" "-")))
 
+;; `stack-element-str` renders one cljw stack frame map {:ns :fn :file :line}
+;; as `<ns>/<fn> (<file>:<line>)`. clj takes a JVM StackTraceElement and yields
+;; `class.method (file:line)` for a Java frame or a demunged `ns/fn` for a
+;; Clojure frame; cljw has no StackTraceElement and only Clojure frames
+;; (ADR-0059 / ADR-0120), so it takes the cljw-native frame map and produces
+;; exactly clj's Clojure-frame form. Same render string as
+;; clojure.stacktrace/print-trace-element (both fixed by ADR-0140).
+(defn stack-element-str
+  "Returns a string representation of one cljw stack frame map
+  {:ns :fn :file :line}, as `<ns>/<fn> (<file>:<line>)`."
+  [{:keys [ns fn file line]}]
+  (str (when ns (str ns "/")) fn " (" (or file "") ":" line ")"))
+
 (defn dir-fn
   "Returns a sorted seq of symbols naming public vars in
   a namespace or namespace alias."

test/clj/suites/repl_test.clj

@@ -33,3 +33,14 @@
     (is (= "ok" (munge "ok"))))
   (testing "munge then demunge round-trips a hyphenated name"
     (is (= "foo-bar" (repl/demunge (munge "foo-bar"))))))
+
+;; --- stack-element-str (cljw-native frame map input) ---
+;; clj takes a JVM StackTraceElement; cljw has only Clojure frames, so it
+;; takes a frame map and produces clj's Clojure-frame render string.
+(deftest stack-element-str-renders-a-frame
+  (testing "a frame map renders as ns/fn (file:line)"
+    (is (= "clojure.core/map (core.clj:2743)"
+           (repl/stack-element-str {:ns "clojure.core" :fn "map" :file "core.clj" :line 2743}))))
+  (testing "a frame with no ns omits the ns/ prefix"
+    (is (= "eval1 (NO_SOURCE_FILE:1)"
+           (repl/stack-element-str {:fn "eval1" :file "NO_SOURCE_FILE" :line 1})))))