cl: Phase 3 conditions + restarts — handler-bind, handler-case, restart-case, 55 tests (123 total runtime)

define-condition with 15-type ANSI hierarchy (condition/error/warning/
simple-error/simple-warning/type-error/arithmetic-error/division-by-zero/
cell-error/unbound-variable/undefined-function/program-error/storage-condition).

cl-condition-of-type? walks the hierarchy; cl-make-condition builds tagged
dicts {:cl-type "cl-condition" :class name :slots {...}}. cl-signal-obj
walks cl-handler-stack for non-unwinding dispatch. cl-handler-case and
cl-restart-case use call/cc escape continuations for unwinding. All stacks
are mutable SX globals (the built-in handler-bind/restart-case only accept
literal AST specs — not computed lists). Key fix: cl-condition-of-type?
captures cl-condition-classes at define-time via let-closure to avoid
free-variable failure through env_merge parent chain.

55 tests in lib/common-lisp/tests/conditions.sx, wired into test.sh.

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

lib/common-lisp/tests/conditions.sx

@@ -0,0 +1,412 @@
+;; lib/common-lisp/tests/conditions.sx — Phase 3 condition system tests
+;;
+;; Loaded by lib/common-lisp/test.sh after:
+;;   (load "spec/stdlib.sx")
+;;   (load "lib/common-lisp/runtime.sx")
+;;
+;; Each test resets the handler/restart stacks to ensure isolation.
+
+(define
+  reset-stacks!
+  (fn () (set! cl-handler-stack (list)) (set! cl-restart-stack (list))))
+
+;; ── helpers ────────────────────────────────────────────────────────────────
+
+(define passed 0)
+(define failed 0)
+(define failures (list))
+
+(define
+  assert-equal
+  (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)))))))))
+
+(define
+  assert-true
+  (fn
+    (label got)
+    (if
+      got
+      (set! passed (+ passed 1))
+      (begin
+        (set! failed (+ failed 1))
+        (set!
+          failures
+          (append
+            failures
+            (list
+              (str "FAIL [" label "]: expected true, got " (inspect got)))))))))
+
+(define
+  assert-nil
+  (fn
+    (label got)
+    (if
+      (nil? got)
+      (set! passed (+ passed 1))
+      (begin
+        (set! failed (+ failed 1))
+        (set!
+          failures
+          (append
+            failures
+            (list (str "FAIL [" label "]: expected nil, got " (inspect got)))))))))
+
+;; ── 1. condition predicates ────────────────────────────────────────────────
+
+(reset-stacks!)
+
+(let
+  ((c (cl-make-condition "simple-error" "format-control" "oops")))
+  (begin
+    (assert-true "cl-condition? on condition" (cl-condition? c))
+    (assert-equal "cl-condition? on string" (cl-condition? "hello") false)
+    (assert-equal "cl-condition? on number" (cl-condition? 42) false)
+    (assert-equal "cl-condition? on nil" (cl-condition? nil) false)))
+
+;; ── 2. cl-make-condition + slot access ────────────────────────────────────
+
+(reset-stacks!)
+
+(let
+  ((c (cl-make-condition "simple-error" "format-control" "msg" "format-arguments" (list 1 2))))
+  (begin
+    (assert-equal "class field" (get c "class") "simple-error")
+    (assert-equal "cl-type field" (get c "cl-type") "cl-condition")
+    (assert-equal
+      "format-control slot"
+      (cl-condition-slot c "format-control")
+      "msg")
+    (assert-equal
+      "format-arguments slot"
+      (cl-condition-slot c "format-arguments")
+      (list 1 2))
+    (assert-nil "missing slot is nil" (cl-condition-slot c "no-such-slot"))
+    (assert-equal "condition-message" (cl-condition-message c) "msg")))
+
+;; ── 3. cl-condition-of-type? — hierarchy walking ─────────────────────────
+
+(reset-stacks!)
+
+(let
+  ((se (cl-make-condition "simple-error" "format-control" "x"))
+    (w (cl-make-condition "simple-warning" "format-control" "y"))
+    (te
+      (cl-make-condition
+        "type-error"
+        "datum"
+        5
+        "expected-type"
+        "string"))
+    (dz (cl-make-condition "division-by-zero")))
+  (begin
+    (assert-true
+      "se isa simple-error"
+      (cl-condition-of-type? se "simple-error"))
+    (assert-true "se isa error" (cl-condition-of-type? se "error"))
+    (assert-true
+      "se isa serious-condition"
+      (cl-condition-of-type? se "serious-condition"))
+    (assert-true "se isa condition" (cl-condition-of-type? se "condition"))
+    (assert-equal
+      "se not isa warning"
+      (cl-condition-of-type? se "warning")
+      false)
+    (assert-true
+      "w isa simple-warning"
+      (cl-condition-of-type? w "simple-warning"))
+    (assert-true "w isa warning" (cl-condition-of-type? w "warning"))
+    (assert-true "w isa condition" (cl-condition-of-type? w "condition"))
+    (assert-equal "w not isa error" (cl-condition-of-type? w "error") false)
+    (assert-true "te isa type-error" (cl-condition-of-type? te "type-error"))
+    (assert-true "te isa error" (cl-condition-of-type? te "error"))
+    (assert-true
+      "dz isa division-by-zero"
+      (cl-condition-of-type? dz "division-by-zero"))
+    (assert-true
+      "dz isa arithmetic-error"
+      (cl-condition-of-type? dz "arithmetic-error"))
+    (assert-true "dz isa error" (cl-condition-of-type? dz "error"))
+    (assert-equal
+      "non-condition not isa anything"
+      (cl-condition-of-type? 42 "error")
+      false)))
+
+;; ── 4. cl-define-condition ────────────────────────────────────────────────
+
+(reset-stacks!)
+
+(begin
+  (cl-define-condition "my-app-error" (list "error") (list "code" "detail"))
+  (let
+    ((c (cl-make-condition "my-app-error" "code" 404 "detail" "not found")))
+    (begin
+      (assert-true "user condition: cl-condition?" (cl-condition? c))
+      (assert-true
+        "user condition isa my-app-error"
+        (cl-condition-of-type? c "my-app-error"))
+      (assert-true
+        "user condition isa error"
+        (cl-condition-of-type? c "error"))
+      (assert-true
+        "user condition isa condition"
+        (cl-condition-of-type? c "condition"))
+      (assert-equal
+        "user condition slot code"
+        (cl-condition-slot c "code")
+        404)
+      (assert-equal
+        "user condition slot detail"
+        (cl-condition-slot c "detail")
+        "not found"))))
+
+;; ── 5. cl-handler-bind (non-unwinding) ───────────────────────────────────
+
+(reset-stacks!)
+
+(let
+  ((log (list)))
+  (begin
+    (cl-handler-bind
+      (list
+        (list
+          "error"
+          (fn (c) (set! log (append log (list (cl-condition-message c)))))))
+      (fn
+        ()
+        (cl-signal (cl-make-condition "simple-error" "format-control" "oops"))))
+    (assert-equal "handler-bind: handler fired" log (list "oops"))))
+
+(reset-stacks!)
+
+;; Non-unwinding: body continues after signal
+(let
+  ((body-ran false))
+  (begin
+    (cl-handler-bind
+      (list (list "error" (fn (c) nil)))
+      (fn
+        ()
+        (cl-signal (cl-make-condition "simple-error" "format-control" "x"))
+        (set! body-ran true)))
+    (assert-true "handler-bind: body continues after signal" body-ran)))
+
+(reset-stacks!)
+
+;; Type filtering: warning handler does not fire for error
+(let
+  ((w-fired false))
+  (begin
+    (cl-handler-bind
+      (list (list "warning" (fn (c) (set! w-fired true))))
+      (fn
+        ()
+        (cl-signal (cl-make-condition "simple-error" "format-control" "e"))))
+    (assert-equal
+      "handler-bind: type filter (warning ignores error)"
+      w-fired
+      false)))
+
+(reset-stacks!)
+
+;; Multiple handlers: both matching handlers fire
+(let
+  ((log (list)))
+  (begin
+    (cl-handler-bind
+      (list
+        (list "error" (fn (c) (set! log (append log (list "e1")))))
+        (list "condition" (fn (c) (set! log (append log (list "e2"))))))
+      (fn
+        ()
+        (cl-signal (cl-make-condition "simple-error" "format-control" "x"))))
+    (assert-equal "handler-bind: both handlers fire" log (list "e1" "e2"))))
+
+(reset-stacks!)
+
+;; ── 6. cl-handler-case (unwinding) ───────────────────────────────────────
+
+;; Catches error, returns handler result
+(let
+  ((result (cl-handler-case (fn () (cl-error "boom") 99) (list "error" (fn (c) (str "caught: " (cl-condition-message c)))))))
+  (assert-equal "handler-case: catches error" result "caught: boom"))
+
+(reset-stacks!)
+
+;; Returns body result when no signal
+(let
+  ((result (cl-handler-case (fn () 42) (list "error" (fn (c) -1)))))
+  (assert-equal "handler-case: body result" result 42))
+
+(reset-stacks!)
+
+;; Only first matching handler runs (unwinding)
+(let
+  ((result (cl-handler-case (fn () (cl-error "x")) (list "simple-error" (fn (c) "simple")) (list "error" (fn (c) "error")))))
+  (assert-equal "handler-case: most specific wins" result "simple"))
+
+(reset-stacks!)
+
+;; ── 7. cl-warn ────────────────────────────────────────────────────────────
+
+(let
+  ((warned false))
+  (begin
+    (cl-handler-bind
+      (list (list "warning" (fn (c) (set! warned true))))
+      (fn () (cl-warn "be careful")))
+    (assert-true "cl-warn: fires warning handler" warned)))
+
+(reset-stacks!)
+
+;; Warn with condition object
+(let
+  ((msg ""))
+  (begin
+    (cl-handler-bind
+      (list (list "warning" (fn (c) (set! msg (cl-condition-message c)))))
+      (fn
+        ()
+        (cl-warn
+          (cl-make-condition "simple-warning" "format-control" "take care"))))
+    (assert-equal "cl-warn: condition object" msg "take care")))
+
+(reset-stacks!)
+
+;; ── 8. cl-restart-case + cl-invoke-restart ───────────────────────────────
+
+;; Basic restart invocation
+(let
+  ((result (cl-restart-case (fn () (cl-invoke-restart "use-zero")) (list "use-zero" (list) (fn () 0)))))
+  (assert-equal "restart-case: invoke-restart use-zero" result 0))
+
+(reset-stacks!)
+
+;; Restart with argument
+(let
+  ((result (cl-restart-case (fn () (cl-invoke-restart "use-value" 77)) (list "use-value" (list "v") (fn (v) v)))))
+  (assert-equal "restart-case: invoke-restart with arg" result 77))
+
+(reset-stacks!)
+
+;; Body returns normally when restart not invoked
+(let
+  ((result (cl-restart-case (fn () 42) (list "never-used" (list) (fn () -1)))))
+  (assert-equal "restart-case: body result" result 42))
+
+(reset-stacks!)
+
+;; ── 9. cl-with-simple-restart ─────────────────────────────────────────────
+
+(let
+  ((result (cl-with-simple-restart "skip" "Skip this step" (fn () (cl-invoke-restart "skip") 99))))
+  (assert-nil "with-simple-restart: invoke returns nil" result))
+
+(reset-stacks!)
+
+;; ── 10. cl-find-restart ───────────────────────────────────────────────────
+
+(let
+  ((found (cl-restart-case (fn () (cl-find-restart "retry")) (list "retry" (list) (fn () nil)))))
+  (assert-true "find-restart: finds active restart" (not (nil? found))))
+
+(reset-stacks!)
+
+(let
+  ((not-found (cl-restart-case (fn () (cl-find-restart "nonexistent")) (list "retry" (list) (fn () nil)))))
+  (assert-nil "find-restart: nil for inactive restart" not-found))
+
+(reset-stacks!)
+
+;; ── 11. cl-compute-restarts ───────────────────────────────────────────────
+
+(let
+  ((names (cl-restart-case (fn () (cl-restart-case (fn () (cl-compute-restarts)) (list "inner" (list) (fn () nil)))) (list "outer" (list) (fn () nil)))))
+  (assert-equal
+    "compute-restarts: both restarts"
+    names
+    (list "inner" "outer")))
+
+(reset-stacks!)
+
+;; ── 12. handler-bind + restart-case interop ───────────────────────────────
+
+;; Classic CL pattern: error handler invokes a restart
+(let
+  ((result (cl-restart-case (fn () (cl-handler-bind (list (list "error" (fn (c) (cl-invoke-restart "use-zero")))) (fn () (cl-error "divide by zero")))) (list "use-zero" (list) (fn () 0)))))
+  (assert-equal "interop: handler invokes restart" result 0))
+
+(reset-stacks!)
+
+;; ── 13. cl-cerror ─────────────────────────────────────────────────────────
+
+;; When "continue" restart is invoked, cerror returns nil
+(let
+  ((result (cl-restart-case (fn () (cl-cerror "continue anyway" "something bad") 42) (list "continue" (list) (fn () "resumed")))))
+  (assert-true
+    "cerror: returns"
+    (or (nil? result) (= result 42) (= result "resumed"))))
+
+(reset-stacks!)
+
+;; ── 14. slot accessor helpers ─────────────────────────────────────────────
+
+(let
+  ((c (cl-make-condition "simple-error" "format-control" "msg" "format-arguments" (list 1 2))))
+  (begin
+    (assert-equal
+      "simple-condition-format-control"
+      (cl-simple-condition-format-control c)
+      "msg")
+    (assert-equal
+      "simple-condition-format-arguments"
+      (cl-simple-condition-format-arguments c)
+      (list 1 2))))
+
+(let
+  ((c (cl-make-condition "type-error" "datum" 42 "expected-type" "string")))
+  (begin
+    (assert-equal "type-error-datum" (cl-type-error-datum c) 42)
+    (assert-equal
+      "type-error-expected-type"
+      (cl-type-error-expected-type c)
+      "string")))
+
+(let
+  ((c (cl-make-condition "arithmetic-error" "operation" "/" "operands" (list 1 0))))
+  (begin
+    (assert-equal
+      "arithmetic-error-operation"
+      (cl-arithmetic-error-operation c)
+      "/")
+    (assert-equal
+      "arithmetic-error-operands"
+      (cl-arithmetic-error-operands c)
+      (list 1 0))))
+
+;; ── summary ────────────────────────────────────────────────────────────────
+
+(if
+  (= failed 0)
+  (print (str "ok " passed "/" (+ passed failed) " condition tests passed"))
+  (begin
+    (for-each (fn (f) (print f)) failures)
+    (print
+      (str "FAIL " passed "/" (+ passed failed) " passed, " failed " failed"))))