erlang: core BIFs + funs, Phase 2 complete (+35 tests)

lib/erlang/tests/eval.sx

@@ -210,6 +210,81 @@
   (nm (ev "case 3 of N when N * 2 > 5 -> big; _ -> small end"))
   "big")
 
+;; ── BIFs: list + tuple ──────────────────────────────────────────
+(er-eval-test "length empty" (ev "length([])") 0)
+(er-eval-test "length 3" (ev "length([a, b, c])") 3)
+(er-eval-test "length cons chain" (ev "length([1 | [2 | [3 | []]]])") 3)
+(er-eval-test "hd" (ev "hd([10, 20, 30])") 10)
+(er-eval-test "hd atom"
+  (nm (ev "hd([ok, err])")) "ok")
+(er-eval-test "tl head"
+  (get (ev "tl([1, 2, 3])") :head) 2)
+(er-eval-test "tl of single" (get (ev "tl([1])") :tag) "nil")
+(er-eval-test "element 1" (nm (ev "element(1, {ok, value})")) "ok")
+(er-eval-test "element 2" (ev "element(2, {ok, 42})") 42)
+(er-eval-test "element 3"
+  (nm (ev "element(3, {a, b, c, d})")) "c")
+(er-eval-test "tuple_size 2" (ev "tuple_size({a, b})") 2)
+(er-eval-test "tuple_size 0" (ev "tuple_size({})") 0)
+
+;; ── BIFs: atom / list conversions ───────────────────────────────
+(er-eval-test "atom_to_list" (ev "atom_to_list(hello)") "hello")
+(er-eval-test "list_to_atom roundtrip"
+  (nm (ev "list_to_atom(atom_to_list(foo))")) "foo")
+(er-eval-test "list_to_atom fresh"
+  (nm (ev "list_to_atom(\"bar\")")) "bar")
+
+;; ── lists module ────────────────────────────────────────────────
+(er-eval-test "lists:reverse empty"
+  (get (ev "lists:reverse([])") :tag) "nil")
+(er-eval-test "lists:reverse 3"
+  (ev "hd(lists:reverse([1, 2, 3]))") 3)
+(er-eval-test "lists:reverse full"
+  (ev "lists:foldl(fun (X, Acc) -> Acc + X end, 0, lists:reverse([1, 2, 3]))") 6)
+
+;; ── funs + lists:map / lists:foldl ──────────────────────────────
+(er-eval-test "fun call" (ev "F = fun (X) -> X + 1 end, F(10)") 11)
+(er-eval-test "fun two-arg"
+  (ev "F = fun (X, Y) -> X * Y end, F(3, 4)") 12)
+(er-eval-test "fun closure"
+  (ev "N = 100, F = fun (X) -> X + N end, F(5)") 105)
+(er-eval-test "fun clauses"
+  (ev "F = fun (0) -> zero; (N) -> N end, element(1, {F(0), F(7)})")
+  (er-mk-atom "zero"))
+(er-eval-test "fun multi-clause second"
+  (ev "F = fun (0) -> 0; (N) -> N * 2 end, F(5)") 10)
+(er-eval-test "lists:map empty"
+  (get (ev "lists:map(fun (X) -> X end, [])") :tag) "nil")
+(er-eval-test "lists:map double"
+  (ev "hd(lists:map(fun (X) -> X * 2 end, [1, 2, 3]))") 2)
+(er-eval-test "lists:map sum-length"
+  (ev "length(lists:map(fun (X) -> X end, [a, b, c, d]))") 4)
+(er-eval-test "lists:foldl sum"
+  (ev "lists:foldl(fun (X, Acc) -> X + Acc end, 0, [1, 2, 3, 4, 5])") 15)
+(er-eval-test "lists:foldl product"
+  (ev "lists:foldl(fun (X, Acc) -> X * Acc end, 1, [1, 2, 3, 4])") 24)
+(er-eval-test "lists:foldl as reverse"
+  (ev "hd(lists:foldl(fun (X, Acc) -> [X | Acc] end, [], [1, 2, 3]))") 3)
+
+;; ── io:format (via capture buffer) ──────────────────────────────
+(er-eval-test "io:format plain"
+  (do (er-io-flush!) (ev "io:format(\"hello~n\")") (er-io-buffer-content))
+  "hello\n")
+(er-eval-test "io:format args"
+  (do (er-io-flush!) (ev "io:format(\"x=~p y=~p~n\", [42, hello])") (er-io-buffer-content))
+  "x=42 y=hello\n")
+(er-eval-test "io:format returns ok"
+  (nm (do (er-io-flush!) (ev "io:format(\"~n\")"))) "ok")
+(er-eval-test "io:format tuple"
+  (do (er-io-flush!) (ev "io:format(\"~p\", [{ok, 1}])") (er-io-buffer-content))
+  "{ok,1}")
+(er-eval-test "io:format list"
+  (do (er-io-flush!) (ev "io:format(\"~p\", [[1,2,3]])") (er-io-buffer-content))
+  "[1,2,3]")
+(er-eval-test "io:format escape"
+  (do (er-io-flush!) (ev "io:format(\"50~~\")") (er-io-buffer-content))
+  "50~")
+
 (define
   er-eval-test-summary
   (str "eval " er-eval-test-pass "/" er-eval-test-count))