stlib arraylist

TODO.md

@@ -743,9 +743,23 @@
   - final open-constant defaults feed one last inference fixpoint before stale
     specializations are pruned
 
-30. basic `std/arraylist` implementation using the new `std/mem` typed allocation
+30. Zig-style type factories and basic `std/arraylist` (implemented; v1)
+  - comptime-only functions may return `type`; anonymous `struct { ... }` expressions and
+    factory calls such as `ArrayList(i32)` resolve to cached nominal concrete types
+  - factory parameters use the existing explicit `$T type` / integer comptime parameters;
+    normal comptime control flow and helper factory calls are supported
+  - type-factory calls work in signatures, nested types, struct literals, and type builtins;
+    runtime materialization and recursive specializations are diagnosed
+  - `std/mem` adds typed `empty` and failure-preserving `realloc`, including overflow,
+    zero-count, zero-sized-type, and alignment handling
+  - `std/arraylist.ArrayList(T)` exposes `items`, `capacity`, and `allocator`, with fallible
+    reserve/append, roughly 1.5x growth from 8, clear-without-free, and reusable deinit
+  - deferred: recursive factories, reflection, inferred type arguments, type-producing
+    unions/enums, pop/insert/remove/shrink/clone container operations
 
-31. disallow arbitrary integer division
+31. threading generic/polymorphic type information everywhere (init, deinit, etc.) might be annoying and verbose. consider whether generic structs could fit nicely to avoid this.
+
+32. disallow arbitrary integer division
   - take inspiration from zig
   - see also below for a word on unchecked casts
   - the user should be explicit about what they mean with integer division (e.g. `div`, `rem`, `trunc`)