cl: Phase 4 CLOS complete — generic functions, multi-dispatch, method qualifiers, 437/437 tests

- lib/common-lisp/clos.sx (27 forms): class registry (8 built-in classes),
  defclass/make-instance/slot-value/slot-boundp/change-class, defgeneric/defmethod
  with :before/:after/:around, clos-call-generic (standard combination: sort by
  specificity, fire befores, call primary chain, fire afters reversed),
  call-next-method/next-method-p, with-slots, deferred accessor installation
- lib/common-lisp/tests/clos.sx: 41 tests (class-of, subclass-of?, defclass,
  make-instance, slot ops, inheritance, method specificity, qualifiers, accessors,
  with-slots, change-class)
- lib/common-lisp/tests/programs/geometry.sx: 12 tests — intersect generic
  dispatching on geo-point×geo-point, geo-point×geo-line, geo-line×geo-line,
  geo-line×geo-plane (multi-dispatch by class precedence)
- lib/common-lisp/tests/programs/mop-trace.sx: 13 tests — :before/:after
  tracing on area and describe-shape generics, call-next-method in circle/rect
- eval.sx: dynamic variables — cl-apply-dyn saves/restores global slot for
  specials; cl-mark-special!/cl-special?/cl-dyn-unbound; defvar now marks
  specials; let/let* rebind via cl-apply-dyn; 8 new tests (182 eval total)
- conformance.sh + test.sh: Phase 4 suites wired in
- plans/common-lisp-on-sx.md: Phase 4 + dynamic variable boxes ticked

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

lib/common-lisp/tests/programs/geometry.sx

@@ -0,0 +1,291 @@
+;; geometry.sx — Multiple dispatch with CLOS
+;;
+;; Demonstrates generic functions dispatching on combinations of
+;; geometric types: point, line, plane.
+;;
+;; Depends on: lib/common-lisp/runtime.sx, lib/common-lisp/clos.sx
+
+;; ── geometric classes ──────────────────────────────────────────────────────
+
+(clos-defclass "geo-point" (list "t") (list {:initform 0 :initarg ":px" :reader nil :writer nil :accessor nil :name "px"} {:initform 0 :initarg ":py" :reader nil :writer nil :accessor nil :name "py"}))
+
+(clos-defclass "geo-line" (list "t") (list {:initform nil :initarg ":p1" :reader nil :writer nil :accessor nil :name "p1"} {:initform nil :initarg ":p2" :reader nil :writer nil :accessor nil :name "p2"}))
+
+(clos-defclass "geo-plane" (list "t") (list {:initform nil :initarg ":normal" :reader nil :writer nil :accessor nil :name "normal"} {:initform 0 :initarg ":d" :reader nil :writer nil :accessor nil :name "d"}))
+
+;; ── helpers ────────────────────────────────────────────────────────────────
+
+(define geo-point-x (fn (p) (clos-slot-value p "px")))
+(define geo-point-y (fn (p) (clos-slot-value p "py")))
+
+(define
+  geo-make-point
+  (fn (x y) (clos-make-instance "geo-point" ":px" x ":py" y)))
+
+(define
+  geo-make-line
+  (fn (p1 p2) (clos-make-instance "geo-line" ":p1" p1 ":p2" p2)))
+
+(define
+  geo-make-plane
+  (fn
+    (nx ny d)
+    (clos-make-instance "geo-plane" ":normal" (list nx ny) ":d" d)))
+
+;; ── describe generic ───────────────────────────────────────────────────────
+
+(clos-defgeneric "geo-describe" {})
+
+(clos-defmethod
+  "geo-describe"
+  (list)
+  (list "geo-point")
+  (fn
+    (args next-fn)
+    (let
+      ((p (first args)))
+      (str "P(" (geo-point-x p) "," (geo-point-y p) ")"))))
+
+(clos-defmethod
+  "geo-describe"
+  (list)
+  (list "geo-line")
+  (fn
+    (args next-fn)
+    (let
+      ((l (first args)))
+      (str
+        "L["
+        (clos-call-generic "geo-describe" (list (clos-slot-value l "p1")))
+        "-"
+        (clos-call-generic "geo-describe" (list (clos-slot-value l "p2")))
+        "]"))))
+
+(clos-defmethod
+  "geo-describe"
+  (list)
+  (list "geo-plane")
+  (fn
+    (args next-fn)
+    (let
+      ((pl (first args)))
+      (str "Plane(d=" (clos-slot-value pl "d") ")"))))
+
+;; ── intersect: multi-dispatch generic ─────────────────────────────────────
+;;
+;; Returns a string description of the intersection result.
+
+(clos-defgeneric "intersect" {})
+
+;; point ∩ point: same if coordinates match
+(clos-defmethod
+  "intersect"
+  (list)
+  (list "geo-point" "geo-point")
+  (fn
+    (args next-fn)
+    (let
+      ((p1 (first args)) (p2 (first (rest args))))
+      (if
+        (and
+          (= (geo-point-x p1) (geo-point-x p2))
+          (= (geo-point-y p1) (geo-point-y p2)))
+        "point"
+        "empty"))))
+
+;; point ∩ line: check if point lies on line (cross product = 0)
+(clos-defmethod
+  "intersect"
+  (list)
+  (list "geo-point" "geo-line")
+  (fn
+    (args next-fn)
+    (let
+      ((pt (first args)) (ln (first (rest args))))
+      (let
+        ((lp1 (clos-slot-value ln "p1")) (lp2 (clos-slot-value ln "p2")))
+        (let
+          ((dx (- (geo-point-x lp2) (geo-point-x lp1)))
+            (dy (- (geo-point-y lp2) (geo-point-y lp1)))
+            (ex (- (geo-point-x pt) (geo-point-x lp1)))
+            (ey (- (geo-point-y pt) (geo-point-y lp1))))
+          (if (= (- (* dx ey) (* dy ex)) 0) "point" "empty"))))))
+
+;; line ∩ line: parallel (same slope = empty) or point
+(clos-defmethod
+  "intersect"
+  (list)
+  (list "geo-line" "geo-line")
+  (fn
+    (args next-fn)
+    (let
+      ((l1 (first args)) (l2 (first (rest args))))
+      (let
+        ((p1 (clos-slot-value l1 "p1"))
+          (p2 (clos-slot-value l1 "p2"))
+          (p3 (clos-slot-value l2 "p1"))
+          (p4 (clos-slot-value l2 "p2")))
+        (let
+          ((dx1 (- (geo-point-x p2) (geo-point-x p1)))
+            (dy1 (- (geo-point-y p2) (geo-point-y p1)))
+            (dx2 (- (geo-point-x p4) (geo-point-x p3)))
+            (dy2 (- (geo-point-y p4) (geo-point-y p3))))
+          (let
+            ((cross (- (* dx1 dy2) (* dy1 dx2))))
+            (if (= cross 0) "parallel" "point")))))))
+
+;; line ∩ plane: general case = point (or parallel if line ⊥ normal)
+(clos-defmethod
+  "intersect"
+  (list)
+  (list "geo-line" "geo-plane")
+  (fn
+    (args next-fn)
+    (let
+      ((ln (first args)) (pl (first (rest args))))
+      (let
+        ((p1 (clos-slot-value ln "p1"))
+          (p2 (clos-slot-value ln "p2"))
+          (n (clos-slot-value pl "normal")))
+        (let
+          ((dx (- (geo-point-x p2) (geo-point-x p1)))
+            (dy (- (geo-point-y p2) (geo-point-y p1)))
+            (nx (first n))
+            (ny (first (rest n))))
+          (let
+            ((dot (+ (* dx nx) (* dy ny))))
+            (if (= dot 0) "parallel" "point")))))))
+
+;; ── tests ─────────────────────────────────────────────────────────────────
+
+(define passed 0)
+(define failed 0)
+(define failures (list))
+
+(define
+  check
+  (fn
+    (label got expected)
+    (if
+      (= got expected)
+      (set! passed (+ passed 1))
+      (begin
+        (set! failed (+ failed 1))
+        (set!
+          failures
+          (append
+            failures
+            (list
+              (str
+                "FAIL ["
+                label
+                "]: got="
+                (inspect got)
+                " expected="
+                (inspect expected)))))))))
+
+;; describe
+(check
+  "describe point"
+  (clos-call-generic
+    "geo-describe"
+    (list (geo-make-point 3 4)))
+  "P(3,4)")
+(check
+  "describe line"
+  (clos-call-generic
+    "geo-describe"
+    (list
+      (geo-make-line
+        (geo-make-point 0 0)
+        (geo-make-point 1 1))))
+  "L[P(0,0)-P(1,1)]")
+(check
+  "describe plane"
+  (clos-call-generic
+    "geo-describe"
+    (list (geo-make-plane 0 1 5)))
+  "Plane(d=5)")
+
+;; intersect point×point
+(check
+  "P∩P same"
+  (clos-call-generic
+    "intersect"
+    (list
+      (geo-make-point 2 3)
+      (geo-make-point 2 3)))
+  "point")
+(check
+  "P∩P diff"
+  (clos-call-generic
+    "intersect"
+    (list
+      (geo-make-point 1 2)
+      (geo-make-point 3 4)))
+  "empty")
+
+;; intersect point×line
+(let
+  ((origin (geo-make-point 0 0))
+    (p10 (geo-make-point 10 0))
+    (p55 (geo-make-point 5 5))
+    (l-x
+      (geo-make-line
+        (geo-make-point 0 0)
+        (geo-make-point 10 0))))
+  (begin
+    (check
+      "P∩L on line"
+      (clos-call-generic "intersect" (list p10 l-x))
+      "point")
+    (check
+      "P∩L on x-axis"
+      (clos-call-generic "intersect" (list origin l-x))
+      "point")
+    (check
+      "P∩L off line"
+      (clos-call-generic "intersect" (list p55 l-x))
+      "empty")))
+
+;; intersect line×line
+(let
+  ((horiz (geo-make-line (geo-make-point 0 0) (geo-make-point 10 0)))
+    (vert
+      (geo-make-line
+        (geo-make-point 5 -5)
+        (geo-make-point 5 5)))
+    (horiz2
+      (geo-make-line
+        (geo-make-point 0 3)
+        (geo-make-point 10 3))))
+  (begin
+    (check
+      "L∩L crossing"
+      (clos-call-generic "intersect" (list horiz vert))
+      "point")
+    (check
+      "L∩L parallel"
+      (clos-call-generic "intersect" (list horiz horiz2))
+      "parallel")))
+
+;; intersect line×plane
+(let
+  ((diag (geo-make-line (geo-make-point 0 0) (geo-make-point 1 1)))
+    (vert-plane (geo-make-plane 1 0 5))
+    (diag-plane (geo-make-plane -1 1 0)))
+  (begin
+    (check
+      "L∩Plane cross"
+      (clos-call-generic "intersect" (list diag vert-plane))
+      "point")
+    (check
+      "L∩Plane parallel"
+      (clos-call-generic "intersect" (list diag diag-plane))
+      "parallel")))
+
+;; ── summary ────────────────────────────────────────────────────────────────
+
+(define geo-passed passed)
+(define geo-failed failed)
+(define geo-failures failures)