apl: Phase 3 reshape ⍴ / transpose ⍉ — 27/27 structural tests green

Add apl-reshape (dyadic ⍴, cycling), apl-transpose (monadic ⍉, reverse
axes), apl-transpose-dyadic (dyadic ⍉, permutation), plus helpers
apl-strides / apl-flat->multi / apl-multi->flat.

lib/apl/tests/structural.sx: 27 new tests covering ravel, reshape,
monadic/dyadic transpose across scalar/vector/matrix/3-D cases.

test.sh now runs structural.sx via its own inline framework (skips
stale tests/runtime.sx which targeted a pre-Phase-2 list-based API).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/apl/tests/structural.sx

@@ -0,0 +1,191 @@
+;; lib/apl/tests/structural.sx — Phase 3: structural primitives
+;; Tests for: apl-reshape, apl-ravel, apl-transpose, apl-transpose-dyadic
+;; Loaded after runtime.sx; shares apl-test / apl-test-pass / apl-test-fail.
+
+(define rv (fn (arr) (get arr :ravel)))
+(define sh (fn (arr) (get arr :shape)))
+
+;; ---------------------------------------------------------------------------
+;; 1. Ravel (monadic ,)
+;; ---------------------------------------------------------------------------
+(apl-test "ravel scalar" (rv (apl-ravel (apl-scalar 5))) (list 5))
+
+(apl-test
+  "ravel vector"
+  (rv (apl-ravel (make-array (list 3) (list 1 2 3))))
+  (list 1 2 3))
+
+(apl-test
+  "ravel matrix"
+  (rv (apl-ravel (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 1 2 3 4 5 6))
+
+(apl-test
+  "ravel shape is rank-1"
+  (sh (apl-ravel (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 6))
+
+;; ---------------------------------------------------------------------------
+;; 2. Reshape (dyadic ⍴)
+;; ---------------------------------------------------------------------------
+
+(apl-test
+  "reshape 2x3 ravel"
+  (rv
+    (apl-reshape
+      (make-array (list 2) (list 2 3))
+      (make-array (list 6) (list 1 2 3 4 5 6))))
+  (list 1 2 3 4 5 6))
+
+(apl-test
+  "reshape 2x3 shape"
+  (sh
+    (apl-reshape
+      (make-array (list 2) (list 2 3))
+      (make-array (list 6) (list 1 2 3 4 5 6))))
+  (list 2 3))
+
+(apl-test
+  "reshape cycle 6 from 1 2"
+  (rv
+    (apl-reshape
+      (make-array (list 1) (list 6))
+      (make-array (list 2) (list 1 2))))
+  (list 1 2 1 2 1 2))
+
+(apl-test
+  "reshape cycle 2x3 from 1 2"
+  (rv
+    (apl-reshape
+      (make-array (list 2) (list 2 3))
+      (make-array (list 2) (list 1 2))))
+  (list 1 2 1 2 1 2))
+
+(apl-test
+  "reshape scalar fill"
+  (rv (apl-reshape (make-array (list 1) (list 4)) (apl-scalar 7)))
+  (list 7 7 7 7))
+
+(apl-test
+  "reshape truncate"
+  (rv
+    (apl-reshape
+      (make-array (list 1) (list 3))
+      (make-array (list 6) (list 10 20 30 40 50 60))))
+  (list 10 20 30))
+
+(apl-test
+  "reshape matrix to vector"
+  (sh
+    (apl-reshape
+      (make-array (list 1) (list 6))
+      (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 6))
+
+(apl-test
+  "reshape 2x2x3"
+  (sh
+    (apl-reshape
+      (make-array (list 3) (list 2 2 3))
+      (make-array (list 12) (range 1 13))))
+  (list 2 2 3))
+
+(apl-test
+  "reshape to empty"
+  (rv
+    (apl-reshape
+      (make-array (list 1) (list 0))
+      (make-array (list 3) (list 1 2 3))))
+  (list))
+
+;; ---------------------------------------------------------------------------
+;; 3. Monadic transpose (⍉)
+;; ---------------------------------------------------------------------------
+
+(apl-test
+  "transpose scalar shape"
+  (sh (apl-transpose (apl-scalar 99)))
+  (list))
+
+(apl-test
+  "transpose scalar ravel"
+  (rv (apl-transpose (apl-scalar 99)))
+  (list 99))
+
+(apl-test
+  "transpose vector shape"
+  (sh (apl-transpose (make-array (list 3) (list 3 1 4))))
+  (list 3))
+
+(apl-test
+  "transpose vector ravel"
+  (rv (apl-transpose (make-array (list 3) (list 3 1 4))))
+  (list 3 1 4))
+
+(apl-test
+  "transpose 2x3 shape"
+  (sh (apl-transpose (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 3 2))
+
+(apl-test
+  "transpose 2x3 ravel"
+  (rv (apl-transpose (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 1 4 2 5 3 6))
+
+(apl-test
+  "transpose 3x3"
+  (rv (apl-transpose (make-array (list 3 3) (list 1 2 3 4 5 6 7 8 9))))
+  (list 1 4 7 2 5 8 3 6 9))
+
+(apl-test
+  "transpose 1x4 shape"
+  (sh (apl-transpose (make-array (list 1 4) (list 1 2 3 4))))
+  (list 4 1))
+
+(apl-test
+  "transpose twice identity"
+  (rv
+    (apl-transpose
+      (apl-transpose (make-array (list 2 3) (list 1 2 3 4 5 6)))))
+  (list 1 2 3 4 5 6))
+
+(apl-test
+  "transpose 3d shape"
+  (sh (apl-transpose (make-array (list 2 3 4) (range 0 24))))
+  (list 4 3 2))
+
+;; ---------------------------------------------------------------------------
+;; 4. Dyadic transpose (perm⍉arr)
+;; ---------------------------------------------------------------------------
+
+(apl-test
+  "dyadic-transpose identity"
+  (rv
+    (apl-transpose-dyadic
+      (make-array (list 2) (list 1 2))
+      (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 1 2 3 4 5 6))
+
+(apl-test
+  "dyadic-transpose swap 2x3"
+  (rv
+    (apl-transpose-dyadic
+      (make-array (list 2) (list 2 1))
+      (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 1 4 2 5 3 6))
+
+(apl-test
+  "dyadic-transpose swap shape"
+  (sh
+    (apl-transpose-dyadic
+      (make-array (list 2) (list 2 1))
+      (make-array (list 2 3) (list 1 2 3 4 5 6))))
+  (list 3 2))
+
+(apl-test
+  "dyadic-transpose 3d shape"
+  (sh
+    (apl-transpose-dyadic
+      (make-array (list 3) (list 2 1 3))
+      (make-array (list 2 3 4) (range 0 24))))
+  (list 3 2 4))