Files
sx/examples/generics/0206-generics-generic-into-block.sx
agra 959845bd30 style: migrate arrow-block lambdas () => { .. } to () { .. }
The canonical sx block-body lambda is `(params) { stmts }` (and
`(params) -> Ret { stmts }`); the arrow form `=>` is for EXPRESSION bodies
(`(params) => expr`). The arrow-block hybrid `(params) => { .. }` was being
used in 33 files — convert all of them by dropping the `=>`. The two forms are
exactly equivalent (verified: identical IR and identical runtime values — the
block tail is the value with or without a `-> Ret`), so this is a pure source
cleanup: no `.ir` churn, and the only snapshot change is 0923's diagnostic
COLUMN (a negative narrowing test whose error span shifted by the removed `=> `).

Arrow EXPRESSION bodies (`=> expr`, `=> .{..}`, `=> [..]`) and `=>` inside
comments/strings were left untouched. Migrated across examples/concurrency,
examples/{closures,ffi-objc,generics,optionals,types}, issues/, and the stdlib
(io.sx, sched.sx). Suite 855/0.
2026-06-28 16:39:51 +03:00

38 lines
1.4 KiB
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// FFI plan step 5.2 — generic `Into(Block) for Closure(..$args) ->
// $R` impl. One impl in stdlib covers every closure shape; the
// compiler monomorphises the impl body per call shape and emits a
// dedicated `__invoke` `abi(.c)` trampoline + Block literal
// (via `#insert build_block_convert($args, $R);`).
//
// This test exercises a closure shape (`Closure(i64, i64) -> void`)
// that has NO hand-rolled `Into(Block)` impl in
// `library/modules/ffi/objc_block.sx`. Before step 5.2 lands,
// `xx cl : Block` errors out with the "no Into(Block) for
// cl_i64_i64__void" focused diagnostic. After the generic impl
// lands, the same call resolves through the pack-shaped impl and
// the per-shape trampoline ferries control back to the sx closure.
//
// The block is invoked directly through `b.invoke` (a typed
// `abi(.c)` fn-pointer) — the same shape the Apple Block
// runtime calls when a UIKit/Foundation API hands the block back
// to its registered invoke.
#import "modules/std.sx";
#import "modules/ffi/objc_block.sx";
g_a: i64 = 0;
g_b: i64 = 0;
main :: () -> i32 {
cl := (a: i64, b: i64) { g_a = a; g_b = b; };
blk : Block = xx cl;
invoke_fn : (*Block, i64, i64) -> void abi(.c) = xx blk.invoke;
invoke_fn(@blk, 10, 20);
if g_a != 10 { print("FAIL: g_a={}\n", g_a); return 1; }
if g_b != 20 { print("FAIL: g_b={}\n", g_b); return 1; }
print("generic-into-block ok: a={} b={}\n", g_a, g_b);
0
}