// issue-0027: Feature — support Obj-C blocks (^{...}) so sx code can call
// APIs that take a block parameter. Required for step 4 of the Metal port
// (keyboard lockstep via `[UIView animateWithDuration:animations:^{...}]`),
// and broadly useful for any UIKit/AppKit API.
//
// ── Proposed surface ──────────────────────────────────────────────────────
//
// Option A — comptime intrinsic that wraps a sx closure as a block:
//
//   block := objc_block(@my_closure);    // returns *void (an id<Block>)
//   msg_block(view, sel, 0.3, block);    // pass like any id arg
//
//   Internals: emit a Block_literal struct constant with the right invoke
//   fn pointer, isa, flags, descriptor pointer. Approximately what clang
//   generates for ^{...}.
//
// Option B — surface-level syntax `^{ ... }` that lowers to Option A
//   automatically. Cleaner for users; more parser work.
//
// Recommended: start with Option A (intrinsic). Migrate to Option B once
// the codegen path is proven.
//
// ── Implementation sketch ────────────────────────────────────────────────
//
// 1. New `library/modules/std/objc_block.sx` defining the Block_literal
//    struct that mirrors clang's layout (isa, flags, reserved, invoke fn
//    pointer, descriptor pointer).
// 2. `objc_block(fn_or_closure) -> *void` intrinsic that builds the
//    literal at the call site. Initial implementation can be a
//    stack-allocated block (_NSConcreteStackBlock); upgrade to
//    heap-promoted (_Block_copy) once block lifetime exceeds the call.
// 3. Link libSystem's symbols `_NSConcreteStackBlock` and
//    `_NSConcreteGlobalBlock` (auto on iOS; may need `#library "System"`
//    on macOS).
// 4. (Deferred) surface syntax `^{ ... }` — parser hook + lowering
//    to the intrinsic. Must not clash with bitwise XOR `^`.
//
// ── References ────────────────────────────────────────────────────────────
//
// - Apple block ABI spec (clang's "Block Implementation Specification")
// - _NSConcreteStackBlock + _NSConcreteGlobalBlock from libSystem
//
// ── Real-world impact ─────────────────────────────────────────────────────
//
// Without this, the keyboard inset cannot be animated in lockstep with the
// keyboard slide. See library/modules/platform/uikit.sx's
// uikit_keyboard_will_change_frame comments for the deferred lockstep work.

#import "modules/std.sx";
main :: () -> s32 { 0; }