apl: control words :If/:While/:For/:Select (+10 tests, 255/255)

lib/apl/tests/tradfn.sx

@@ -10,6 +10,14 @@
 (define mkasg (fn (n e) (list :assign n e)))
 (define mkbr (fn (e) (list :branch e)))
 
+(define mkif (fn (c t e) (list :if c t e)))
+
+(define mkwhile (fn (c b) (list :while c b)))
+
+(define mkfor (fn (v i b) (list :for v i b)))
+
+(define mksel (fn (v cs d) (list :select v cs d)))
+
 (apl-test
   "tradfn R←L+W simple add"
   (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkasg "R" (mkdyd "+" (mknm "L") (mknm "W")))) :alpha "L"} (apl-scalar 5) (apl-scalar 7)))
@@ -63,3 +71,57 @@
   "tradfn loop sum 1+2+...+5 via branch"
   (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkasg "i" (mknum 1)) (mkasg "R" (mknum 0)) (mkasg "R" (mkdyd "+" (mknm "R") (mknm "i"))) (mkasg "i" (mkdyd "+" (mknm "i") (mknum 1))) (mkbr (mkdyd "×" (mkdyd "≤" (mknm "i") (mknm "W")) (mknum 3)))) :alpha nil} nil (apl-scalar 5)))
   (list 15))
+
+(apl-test
+  "tradfn :If true branch"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkif (mkdyd ">" (mknm "W") (mknum 0)) (list (mkasg "R" (mknum 1))) (list (mkasg "R" (mknum 0))))) :alpha nil} nil (apl-scalar 5)))
+  (list 1))
+
+(apl-test
+  "tradfn :If false branch"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkif (mkdyd ">" (mknm "W") (mknum 100)) (list (mkasg "R" (mknum 1))) (list (mkasg "R" (mknum 0))))) :alpha nil} nil (apl-scalar 5)))
+  (list 0))
+
+(apl-test
+  "tradfn :While sum 1..N"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkasg "i" (mknum 1)) (mkasg "R" (mknum 0)) (mkwhile (mkdyd "≤" (mknm "i") (mknm "W")) (list (mkasg "R" (mkdyd "+" (mknm "R") (mknm "i"))) (mkasg "i" (mkdyd "+" (mknm "i") (mknum 1)))))) :alpha nil} nil (apl-scalar 10)))
+  (list 55))
+
+(apl-test
+  "tradfn :For sum elements"
+  (mkrv
+    (apl-call-tradfn
+      {:result "R" :omega "W" :stmts (list (mkasg "R" (mknum 0)) (mkfor "x" (mknm "W") (list (mkasg "R" (mkdyd "+" (mknm "R") (mknm "x")))))) :alpha nil}
+      nil
+      (make-array (list 4) (list 10 20 30 40))))
+  (list 100))
+
+(apl-test
+  "tradfn :For with empty vector"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkasg "R" (mknum 99)) (mkfor "x" (mknm "W") (list (mkasg "R" (mkdyd "+" (mknm "R") (mknm "x")))))) :alpha nil} nil (make-array (list 0) (list))))
+  (list 99))
+
+(apl-test
+  "tradfn :Select dispatch hit"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mksel (mknm "W") (list (list (mknum 1) (mkasg "R" (mknum 100))) (list (mknum 2) (mkasg "R" (mknum 200))) (list (mknum 3) (mkasg "R" (mknum 300)))) (list (mkasg "R" (mknum 0))))) :alpha nil} nil (apl-scalar 2)))
+  (list 200))
+
+(apl-test
+  "tradfn :Select default block"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mksel (mknm "W") (list (list (mknum 1) (mkasg "R" (mknum 100))) (list (mknum 2) (mkasg "R" (mknum 200)))) (list (mkasg "R" (mknum -1))))) :alpha nil} nil (apl-scalar 99)))
+  (list -1))
+
+(apl-test
+  "tradfn nested :If"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkif (mkdyd ">" (mknm "W") (mknum 0)) (list (mkif (mkdyd ">" (mknm "W") (mknum 10)) (list (mkasg "R" (mknum 2))) (list (mkasg "R" (mknum 1))))) (list (mkasg "R" (mknum 0))))) :alpha nil} nil (apl-scalar 5)))
+  (list 1))
+
+(apl-test
+  "tradfn :If assigns persist outside"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkasg "R" (mknum 0)) (mkif (mkdyd ">" (mknm "W") (mknum 0)) (list (mkasg "R" (mknum 42))) (list)) (mkasg "R" (mkdyd "+" (mknm "R") (mknum 1)))) :alpha nil} nil (apl-scalar 5)))
+  (list 43))
+
+(apl-test
+  "tradfn :For factorial 1..5"
+  (mkrv (apl-call-tradfn {:result "R" :omega "W" :stmts (list (mkasg "R" (mknum 1)) (mkfor "x" (mkmon "⍳" (mknm "W")) (list (mkasg "R" (mkdyd "×" (mknm "R") (mknm "x")))))) :alpha nil} nil (apl-scalar 5)))
+  (list 120))

lib/apl/transpile.sx

@@ -189,6 +189,94 @@
       ((stmts (rest dfn-ast)) (env {:omega omega :nabla dfn-ast :alpha nil}))
       (apl-eval-stmts stmts env))))
 
+(define
+  apl-tradfn-eval-block
+  (fn
+    (stmts env)
+    (if
+      (= (len stmts) 0)
+      env
+      (let
+        ((stmt (first stmts)))
+        (apl-tradfn-eval-block (rest stmts) (apl-tradfn-eval-stmt stmt env))))))
+
+(define
+  apl-tradfn-eval-while
+  (fn
+    (cond-expr body env)
+    (let
+      ((cond-val (apl-eval-ast cond-expr env)))
+      (if
+        (apl-truthy? cond-val)
+        (apl-tradfn-eval-while
+          cond-expr
+          body
+          (apl-tradfn-eval-block body env))
+        env))))
+
+(define
+  apl-tradfn-eval-for
+  (fn
+    (var-name items body env)
+    (if
+      (= (len items) 0)
+      env
+      (let
+        ((env-with-var (assoc env var-name (apl-scalar (first items)))))
+        (apl-tradfn-eval-for
+          var-name
+          (rest items)
+          body
+          (apl-tradfn-eval-block body env-with-var))))))
+
+(define
+  apl-tradfn-eval-select
+  (fn
+    (val cases default-block env)
+    (if
+      (= (len cases) 0)
+      (apl-tradfn-eval-block default-block env)
+      (let
+        ((c (first cases)))
+        (let
+          ((case-val (apl-eval-ast (first c) env)))
+          (if
+            (= (first (get val :ravel)) (first (get case-val :ravel)))
+            (apl-tradfn-eval-block (rest c) env)
+            (apl-tradfn-eval-select val (rest cases) default-block env)))))))
+
+(define
+  apl-tradfn-eval-stmt
+  (fn
+    (stmt env)
+    (let
+      ((tag (first stmt)))
+      (cond
+        ((= tag :assign)
+          (assoc env (nth stmt 1) (apl-eval-ast (nth stmt 2) env)))
+        ((= tag :if)
+          (let
+            ((cond-val (apl-eval-ast (nth stmt 1) env)))
+            (if
+              (apl-truthy? cond-val)
+              (apl-tradfn-eval-block (nth stmt 2) env)
+              (apl-tradfn-eval-block (nth stmt 3) env))))
+        ((= tag :while)
+          (apl-tradfn-eval-while (nth stmt 1) (nth stmt 2) env))
+        ((= tag :for)
+          (let
+            ((iter-val (apl-eval-ast (nth stmt 2) env)))
+            (apl-tradfn-eval-for
+              (nth stmt 1)
+              (get iter-val :ravel)
+              (nth stmt 3)
+              env)))
+        ((= tag :select)
+          (let
+            ((val (apl-eval-ast (nth stmt 1) env)))
+            (apl-tradfn-eval-select val (nth stmt 2) (nth stmt 3) env)))
+        (else (begin (apl-eval-ast stmt env) env))))))
+
 (define
   apl-tradfn-loop
   (fn
@@ -208,18 +296,12 @@
                   (let
                     ((target-num (first (get target :ravel))))
                     (apl-tradfn-loop stmts target-num env result-name))))
-              ((= tag :assign)
-                (let
-                  ((v (apl-eval-ast (nth stmt 2) env)))
-                  (apl-tradfn-loop
-                    stmts
-                    (+ line 1)
-                    (assoc env (nth stmt 1) v)
-                    result-name)))
               (else
-                (begin
-                  (apl-eval-ast stmt env)
-                  (apl-tradfn-loop stmts (+ line 1) env result-name))))))))))
+                (apl-tradfn-loop
+                  stmts
+                  (+ line 1)
+                  (apl-tradfn-eval-stmt stmt env)
+                  result-name)))))))))
 
 (define
   apl-call-tradfn

plans/apl-on-sx.md

@@ -89,7 +89,7 @@ Core mapping:
 - [x] Dfn `{…}` with `⍺` (left arg, may be absent → niladic/monadic), `⍵` (right arg), `∇` (recurse), guards `cond:expr`, default left arg `⍺←default`
 - [x] Local assignment via `←` (lexical inside dfn)
 - [x] Tradfn `∇` header: `R←L F R;l1;l2`, statement-by-statement, branch via `→linenum`
-- [ ] Dyalog control words: `:If/:Else/:EndIf`, `:While/:EndWhile`, `:For X :In V :EndFor`, `:Select/:Case/:EndSelect`, `:Trap`/`:EndTrap`
+- [x] Dyalog control words: `:If/:Else/:EndIf`, `:While/:EndWhile`, `:For X :In V :EndFor`, `:Select/:Case/:EndSelect`, `:Trap`/`:EndTrap` _(Trap deferred — no exception machinery yet)_
 - [ ] Niladic / monadic / dyadic dispatch (function valence at definition time)
 - [ ] `lib/apl/conformance.sh` + runner, `scoreboard.json` + `scoreboard.md`
 
@@ -118,6 +118,7 @@ data; format for string templating.
 
 _Newest first._
 
+- 2026-05-07: Phase 5 control words — :If/:Else, :While, :For/:In, :Select/:Case via apl-tradfn-eval-block/stmt threading env; :Trap deferred; +10 tests (sum loop, factorial, dispatch, nested); 255/255 tests
 - 2026-05-07: Phase 5 tradfn — apl-call-tradfn + apl-tradfn-loop; line-numbered stmts, :branch goto, →0 exits, locals; +10 tests including loop sum; 245/245 tests
 - 2026-05-07: Phase 5 dfn complete — apl-eval-stmts (guards, locals, ⍺←default), ∇ recursion via env "nabla"; +9 tests (factorial, guards, defaults, locals); 235/235 tests
 - 2026-05-07: Phase 5 dfn foundation — lib/apl/transpile.sx with apl-eval-ast (handles :num :vec :name :monad :dyad :program :dfn) + glyph→fn lookup tables; apl-call-dfn / apl-call-dfn-m bind ⍺/⍵; ∇/guards/defaults/locals pending; 226/226 tests