lua: generic for-in; ipairs/pairs/next; arity-tolerant fns +9 tests

lib/lua/test.sh

@@ -681,6 +681,35 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 911)
 (eval "(lua-eval-ast \"local function f() return 99 end local function handler(e) return e end local ok, v = xpcall(f, handler) return v\")")
 
+;; ── Phase 4: generic `for … in …` ──────────────────────────────
+;; ipairs over array
+(epoch 950)
+(eval "(lua-eval-ast \"local t = {10, 20, 30} local sum = 0 for i, v in ipairs(t) do sum = sum + v end return sum\")")
+(epoch 951)
+(eval "(lua-eval-ast \"local t = {10, 20, 30} local last = 0 for i, v in ipairs(t) do last = i end return last\")")
+(epoch 952)
+(eval "(lua-eval-ast \"local t = {} local count = 0 for i, v in ipairs(t) do count = count + 1 end return count\")")
+(epoch 953)
+(eval "(lua-eval-ast \"local t = {1, 2, nil, 4} local c = 0 for i, v in ipairs(t) do c = c + 1 end return c\")")
+
+;; pairs over hash
+(epoch 960)
+(eval "(lua-eval-ast \"local t = {a = 1, b = 2, c = 3} local sum = 0 for k, v in pairs(t) do sum = sum + v end return sum\")")
+(epoch 961)
+(eval "(lua-eval-ast \"local t = {x = 1, y = 2, z = 3} local n = 0 for k, v in pairs(t) do n = n + 1 end return n\")")
+
+;; custom stateful iterator (if-else-return, works around early-return limit)
+(epoch 970)
+(eval "(lua-eval-ast \"local function range(n) local i = 0 return function() i = i + 1 if i > n then return nil else return i end end end local c = 0 for x in range(5) do c = c + x end return c\")")
+
+;; 3-value iterator form (f, s, var)
+(epoch 971)
+(eval "(lua-eval-ast \"local function step(max, i) if i >= max then return nil else return i + 1, (i + 1) * (i + 1) end end local sum = 0 for i, v in step, 4, 0 do sum = sum + v end return sum\")")
+
+;; pairs ignores __meta key
+(epoch 980)
+(eval "(lua-eval-ast \"local t = setmetatable({x = 1, y = 2}, {}) local n = 0 for k in pairs(t) do n = n + 1 end return n\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 60 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -1022,6 +1051,17 @@ check 906 "nested pcall"                    '"outer:inner"'
 check 910 "xpcall invokes handler"          '"H:raw"'
 check 911 "xpcall ok path"                  '99'
 
+# ── Phase 4: generic `for … in …` ─────────────────────────────
+check 950 "ipairs sum"                      '60'
+check 951 "ipairs last index"               '3'
+check 952 "ipairs empty → 0"                '0'
+check 953 "ipairs stops at nil"             '2'
+check 960 "pairs hash sum"                  '6'
+check 961 "pairs hash count"                '3'
+check 970 "stateful closure iter"           '15'
+check 971 "3-value iterator form"           '30'
+check 980 "pairs skips __meta"              '2'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL Lua-on-SX tests passed"