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

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