compiler: self-hosted analyzer compiles set literals (#{…})

Stage 1 Task 1. analyzer.clj punted set literals to the interpreter
((form-set? form) (uncompilable "set literal")); now it builds the set-node IR
(already defined in ir.clj) from (form-set-items form), and backend.janet emits
(make-phs e1 e2 …) — each element evaluated then the persistent set built,
mirroring compiler.janet's emit-set-expr and the interpreter's :jolt/set path.

Closes a self-hosted-analyzer vs bootstrap-compiler parity gap: #{…} no longer
forces interpreter fallback on the compile path.

Gate: conformance 262x3 (+4 set-literal cases incl computed elements / empty /
in-let), fixpoint, self-host, sci, suite 3981/66, specs+unit green; core-bench
neutral (A/B). set?/disj-as-fns remain deliberately interpreted (in-sync across
all three lists) — adjudicated in Task 2.

jolt-core/jolt/analyzer.clj

@@ -15,12 +15,12 @@
   declared — the bootstrap compiles forward refs through var cells, but keeping
   them to one keeps the compiled namespace simple."
   (:require [jolt.ir :refer [const local var-ref host-ref if-node do-node invoke
-                             def-node let-node fn-node vector-node map-node
+                             def-node let-node fn-node vector-node map-node set-node
                              quote-node throw-node]]
             [jolt.host :refer [form-sym? form-sym-name form-sym-ns form-list?
                                form-vec? form-map? form-set? form-char?
                                form-literal? form-elements form-vec-items
-                               form-map-pairs form-special? compile-ns
+                               form-map-pairs form-set-items form-special? compile-ns
                                form-macro? form-expand-1 resolve-global
                                form-sym-meta host-intern! form-syntax-quote-lower]]))
 
@@ -207,6 +207,6 @@
      (form-map? form) (map-node (mapv (fn [p] [(analyze ctx (first p) env)
                                               (analyze ctx (second p) env)])
                                      (form-map-pairs form)))
-     (form-set? form) (uncompilable "set literal")
+     (form-set? form) (set-node (mapv #(analyze ctx % env) (form-set-items form)))
      (form-list? form) (analyze-list ctx form env)
      :else (uncompilable "unsupported form"))))

src/jolt/backend.janet

@@ -230,6 +230,12 @@
     (array/push args (emit ctx (in p 1))))
   (tuple/slice args))
 
+# A set literal: build (make-phs e1 e2 …) so each element is evaluated at runtime
+# then the persistent set is constructed — mirrors compiler.janet's emit-set-expr.
+(defn- emit-set [ctx node]
+  (def items (map |(emit ctx $) (vview (node :items))))
+  (tuple/slice (array/concat @[phm/make-phs] items)))
+
 (set emit
   (fn emit [ctx raw]
     (def node (norm-node raw))
@@ -259,6 +265,7 @@
       :invoke (emit-invoke ctx node)
       :vector (emit-vector ctx node)
       :map (emit-map ctx node)
+      :set (emit-set ctx node)
       :quote ['quote (node :form)]
       (error (string "backend: unhandled op " (node :op))))))
 

test/integration/conformance-test.janet

@@ -50,6 +50,12 @@
    ["map as fn default" "99" "({:a 1} :z 99)"]
    ["set as fn"     "2"   "(#{1 2 3} 2)"]
    ["set as fn miss" "nil" "(#{1 2 3} 9)"]
+   # set literals compile (Stage 1 Task 1): computed elements are each evaluated
+   # then the persistent set is built, matching the interpreter.
+   ["set literal computed" "true" "(= #{1 2} #{(inc 0) 2})"]
+   ["empty set literal"    "true" "(empty? #{})"]
+   ["set literal count"    "3"    "(count #{1 2 3})"]
+   ["set literal in let"   "true" "(let [x 5] (= #{5 6} #{x (inc x)}))"]
    ["keyword as fn" "1"   "(:a {:a 1})"]
    ["map fn over coll" "(quote (1 3))" "(map {:a 1 :b 3} [:a :b])"]