ocaml: phase 6 stdlib slice (List/Option/Result, +23 tests, 248 total)

lib/ocaml/runtime.sx defines the stdlib in OCaml syntax (not SX): every
function exercises the parser, evaluator, match engine, and module
machinery built in earlier phases. Loaded once via ocaml-load-stdlib!,
cached in ocaml-stdlib-env, layered under user code via ocaml-base-env.

List: length, rev, rev_append, map, filter, fold_left/right, append,
iter, mem, for_all, exists, hd, tl, nth.
Option: map, bind, value, get, is_none, is_some.
Result: map, bind, is_ok, is_error.

Substrate validation: this stdlib is a nontrivial OCaml program — its
mere existence proves the substrate works.

lib/ocaml/test.sh

@@ -33,7 +33,9 @@ cat > "$TMPFILE" << 'EPOCHS'
 (load "lib/ocaml/tokenizer.sx")
 (load "lib/ocaml/parser.sx")
 (load "lib/ocaml/eval.sx")
+(load "lib/ocaml/runtime.sx")
 (load "lib/ocaml/tests/tokenize.sx")
+(eval "(ocaml-load-stdlib!)")
 
 ;; ── empty / eof ────────────────────────────────────────────────
 (epoch 100)
@@ -579,6 +581,56 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 754)
 (eval "(ocaml-run-program \"module Identity (M) = struct include M end ;; module Base = struct let v = 99 end ;; module Same = Identity(Base) ;; Same.v\")")
 
+;; ── Phase 6: stdlib slice (List, Option, Result) ───────────────
+(epoch 800)
+(eval "(ocaml-run \"List.length [1; 2; 3; 4]\")")
+(epoch 801)
+(eval "(ocaml-run \"List.length []\")")
+(epoch 802)
+(eval "(ocaml-run \"List.map (fun x -> x * 2) [1; 2; 3]\")")
+(epoch 803)
+(eval "(ocaml-run \"List.filter (fun x -> x > 2) [1; 2; 3; 4; 5]\")")
+(epoch 804)
+(eval "(ocaml-run \"List.fold_left (fun a b -> a + b) 0 [1; 2; 3; 4; 5]\")")
+(epoch 805)
+(eval "(ocaml-run \"List.fold_right (fun x acc -> x :: acc) [1; 2; 3] []\")")
+(epoch 806)
+(eval "(ocaml-run \"List.rev [1; 2; 3]\")")
+(epoch 807)
+(eval "(ocaml-run \"List.append [1; 2] [3; 4]\")")
+(epoch 808)
+(eval "(ocaml-run \"List.mem 3 [1; 2; 3]\")")
+(epoch 809)
+(eval "(ocaml-run \"List.mem 99 [1; 2; 3]\")")
+(epoch 810)
+(eval "(ocaml-run \"List.for_all (fun x -> x > 0) [1; 2; 3]\")")
+(epoch 811)
+(eval "(ocaml-run \"List.exists (fun x -> x > 2) [1; 2; 3]\")")
+(epoch 812)
+(eval "(ocaml-run \"List.hd [10; 20; 30]\")")
+(epoch 813)
+(eval "(ocaml-run \"List.nth [10; 20; 30] 1\")")
+
+(epoch 820)
+(eval "(ocaml-run \"Option.map (fun x -> x + 1) (Some 41)\")")
+(epoch 821)
+(eval "(ocaml-run \"Option.map (fun x -> x + 1) None\")")
+(epoch 822)
+(eval "(ocaml-run \"Option.value (Some 7) 0\")")
+(epoch 823)
+(eval "(ocaml-run \"Option.value None 42\")")
+(epoch 824)
+(eval "(ocaml-run \"Option.is_some (Some 1)\")")
+(epoch 825)
+(eval "(ocaml-run \"Option.is_none None\")")
+
+(epoch 830)
+(eval "(ocaml-run \"Result.map (fun x -> x + 1) (Ok 5)\")")
+(epoch 831)
+(eval "(ocaml-run \"Result.is_ok (Ok 1)\")")
+(epoch 832)
+(eval "(ocaml-run \"Result.is_error (Error \\\"oops\\\")\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 60 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -921,6 +973,36 @@ check 752 "submodule alias"              '42'
 check 753 "multi-param functor"          '("tuple" 1 2)'
 check 754 "Identity functor + include"   '99'
 
+# ── Phase 6: stdlib slice ───────────────────────────────────────
+# List
+check 800 "List.length [1..4]"           '4'
+check 801 "List.length []"               '0'
+check 802 "List.map x*2 [1;2;3]"         '(2 4 6)'
+check 803 "List.filter > 2"              '(3 4 5)'
+check 804 "List.fold_left + 0 [1..5]"    '15'
+check 805 "List.fold_right ::"           '(1 2 3)'
+check 806 "List.rev"                     '(3 2 1)'
+check 807 "List.append"                  '(1 2 3 4)'
+check 808 "List.mem 3"                   'true'
+check 809 "List.mem 99"                  'false'
+check 810 "List.for_all >0"              'true'
+check 811 "List.exists >2"               'true'
+check 812 "List.hd"                      '10'
+check 813 "List.nth idx 1"               '20'
+
+# Option
+check 820 "Option.map Some"              '("Some" 42)'
+check 821 "Option.map None"              '("None")'
+check 822 "Option.value Some"            '7'
+check 823 "Option.value None"            '42'
+check 824 "Option.is_some"               'true'
+check 825 "Option.is_none"               'true'
+
+# Result
+check 830 "Result.map Ok"                '("Ok" 6)'
+check 831 "Result.is_ok"                 'true'
+check 832 "Result.is_error"              'true'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL OCaml-on-SX tests passed"