apl: ∪ unique / ∪ union / ∩ intersection (+12)

- apl-unique: dedup keeping first-occurrence order
- apl-union: dedup'd A then B-elements-not-in-A
- apl-intersect: A elements that are in B, preserves left order
- ∪ wired both monadic and dyadic; ∩ wired dyadic
- pipeline 121/121

lib/apl/runtime.sx

@@ -852,6 +852,40 @@
           (apl-scalar (first result))
           (make-array (get vals :shape) result))))))
 
+(define
+  apl-unique
+  (fn
+    (arr)
+    (let
+      ((ravel (if (scalar? arr) (list (disclose arr)) (get arr :ravel))))
+      (let
+        ((dedup (reduce (fn (acc x) (if (index-of acc x) acc (append acc (list x)))) (list) ravel)))
+        (apl-vector dedup)))))
+
+(define
+  apl-union
+  (fn
+    (a b)
+    (let
+      ((a-ravel (if (scalar? a) (list (disclose a)) (get a :ravel)))
+        (b-ravel (if (scalar? b) (list (disclose b)) (get b :ravel))))
+      (let
+        ((a-dedup (reduce (fn (acc x) (if (index-of acc x) acc (append acc (list x)))) (list) a-ravel)))
+        (let
+          ((b-extra (filter (fn (x) (not (index-of a-dedup x))) b-ravel)))
+          (let
+            ((b-extra-dedup (reduce (fn (acc x) (if (index-of acc x) acc (append acc (list x)))) (list) b-extra)))
+            (apl-vector (append a-dedup b-extra-dedup))))))))
+
+(define
+  apl-intersect
+  (fn
+    (a b)
+    (let
+      ((a-ravel (if (scalar? a) (list (disclose a)) (get a :ravel)))
+        (b-ravel (if (scalar? b) (list (disclose b)) (get b :ravel))))
+      (apl-vector (filter (fn (x) (index-of b-ravel x)) a-ravel)))))
+
 (define
   apl-primes
   (fn

lib/apl/tests/pipeline.sx

@@ -497,3 +497,50 @@
     "⍸ interval-index: y above all → len breaks"
     (mkrv (apl-run "10 20 30 ⍸ 100"))
     (list 3)))
+
+(begin
+  (apl-test
+    "∪ unique: dedup keeps first-occurrence order"
+    (mkrv (apl-run "∪ 1 2 1 3 2 1 4"))
+    (list 1 2 3 4))
+  (apl-test
+    "∪ unique: already-unique unchanged"
+    (mkrv (apl-run "∪ 5 4 3 2 1"))
+    (list 5 4 3 2 1))
+  (apl-test "∪ unique: scalar" (mkrv (apl-run "∪ 7")) (list 7))
+  (apl-test
+    "∪ unique: string mississippi → misp"
+    (mkrv (apl-run "∪ 'mississippi'"))
+    (list "m" "i" "s" "p"))
+  (apl-test
+    "∪ union: 1 2 3 ∪ 3 4 5 → 1 2 3 4 5"
+    (mkrv (apl-run "1 2 3 ∪ 3 4 5"))
+    (list 1 2 3 4 5))
+  (apl-test
+    "∪ union: dedups left side too"
+    (mkrv (apl-run "1 2 1 ∪ 1 3 2"))
+    (list 1 2 3))
+  (apl-test
+    "∪ union: disjoint → catenated"
+    (mkrv (apl-run "1 2 ∪ 3 4"))
+    (list 1 2 3 4))
+  (apl-test
+    "∩ intersection: 1 2 3 4 ∩ 2 4 6 → 2 4"
+    (mkrv (apl-run "1 2 3 4 ∩ 2 4 6"))
+    (list 2 4))
+  (apl-test
+    "∩ intersection: disjoint → empty"
+    (mkrv (apl-run "1 2 3 ∩ 4 5 6"))
+    (list))
+  (apl-test
+    "∩ intersection: preserves left order"
+    (mkrv (apl-run "(⍳5) ∩ 5 3 1"))
+    (list 1 3 5))
+  (apl-test
+    "∩ intersection: identical"
+    (mkrv (apl-run "1 2 3 ∩ 1 2 3"))
+    (list 1 2 3))
+  (apl-test
+    "∪/∩ identity: A ∪ A = ∪A"
+    (mkrv (apl-run "1 2 1 ∪ 1 2 1"))
+    (list 1 2)))

lib/apl/transpile.sx

@@ -47,6 +47,7 @@
       ((= g "⎕FMT") apl-quad-fmt)
       ((= g "⎕←") apl-quad-print)
       ((= g "⍸") apl-where)
+      ((= g "∪") apl-unique)
       (else (error "no monadic fn for glyph")))))
 
 (define
@@ -92,6 +93,8 @@
       ((= g "⊢") (fn (a b) b))
       ((= g "⊣") (fn (a b) a))
       ((= g "⍸") apl-interval-index)
+      ((= g "∪") apl-union)
+      ((= g "∩") apl-intersect)
       (else (error "no dyadic fn for glyph")))))
 
 (define