✓
Passing This code compiles and runs correctly.
Code
// PARAM CAPTURE LANDED (2026-08-03). This pin was red on purpose and carried
// its own flip instruction: "When param capture lands, this flips to MUST_RUN
// with expected '7 5'." Done — it is MUST_RUN now.
//
// What was missing was never a scope rule. A tor's parameter materializes as a
// `const d = __koru_event_input.d;` in the very frame that calls the sweep, one
// line above the call, exactly like the mid-chain bind that already worked. The
// capture collector simply never looked at the parameter list: it gathered
// mid-pipe binds, and gathered event INPUTS only when the host flow was a
// synthesized `__store_sweepbody_` (the nested-sweep case). A user tor never
// took that branch. The threading the fix needs was already there and already
// correct — a sweep arm inside a tor body captures a mid-chain bind today.
//
// The contrast this pin recorded is what proved it: a BRANCH binding threads
// fine, only the tor-parameter route was missing. Same body position, same
// generated arithmetic, same hop count — one origin, not one scope, was the
// whole difference.
//
// So the cost this pin named is paid off too: a "helper tor that writes a
// store" (kopium's absorb) no longer has to be inlined at its call sites.
//
// NOT governed by DESIGN.md T1. T1 is transplant-purity for a WATCH body —
// spliced into the store's write path, executing wherever a write happens, so
// it genuinely cannot close over its declaring scope. A sweep body runs AT the
// sweep site in the caller's own frame; its lift into a handler fn is codegen,
// not relocation to a foreign execution context.
//
// STILL OPEN, and a different defect: capturing anything into a sweep body
// declared inside an imported MODULE fails with `use of undeclared identifier
// '__koru_store_bodies'`. That predates this change — a mid-chain bind capture
// in a module sweep body fails identically — and is the store symbol being
// named from a namespace it is not in.
import std/io
import std/store
std/store:new(box, capacity: 4) { n: i64 }
std/store:insert(box) { n: 7 }
| row _ |> _
| full |> _
tor shout { d: i64 }
shout = std/store:query(box)
! query r |> std/io:print.ln("{{ r.n:d }} {{ d:d }}")
shout(d: 5)
Actual
7 5
Expected output
✓ Zig✓ C#7 5
Emitted Zig source
// Access compiler flags via the per-user compiler_env module
const CompilerEnv = @import("compiler_env").CompilerEnv;
pub const panic = if (@import("builtin").mode == .Debug)
@import("std").debug.FullPanic(@import("std").debug.defaultPanic)
else
@import("std").debug.simple_panic;
const __koru_bare = struct {
extern fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: usize) c_int;
extern fn free(ptr: ?*anyopaque) void;
fn bareAlloc(_: *anyopaque, len: usize, alignment: @import("std").mem.Alignment, _: usize) ?[*]u8 {
var p: ?*anyopaque = null;
const a = @max(alignment.toByteUnits(), @sizeOf(usize));
if (posix_memalign(&p, a, len) != 0) return null;
return @ptrCast(p);
}
fn bareResize(_: *anyopaque, _: []u8, _: @import("std").mem.Alignment, _: usize, _: usize) bool { return false; }
fn bareRemap(_: *anyopaque, _: []u8, _: @import("std").mem.Alignment, _: usize, _: usize) ?[*]u8 { return null; }
fn bareFree(_: *anyopaque, memory: []u8, _: @import("std").mem.Alignment, _: usize) void { free(@ptrCast(memory.ptr)); }
const vtable = @import("std").mem.Allocator.VTable{ .alloc = bareAlloc, .resize = bareResize, .remap = bareRemap, .free = bareFree };
const allocator = @import("std").mem.Allocator{ .ptr = undefined, .vtable = &vtable };
};
const __koru_backing = if (@import("builtin").link_libc) @import("std").heap.c_allocator else if (@import("builtin").os.tag == .freestanding) __koru_bare.allocator else @import("std").heap.page_allocator;
var __koru_leak_count: usize = 0;
fn __koru_alloc(ctx: *anyopaque, len: usize, alignment: @import("std").mem.Alignment, ret_addr: usize) ?[*]u8 {
_ = ctx;
const r = __koru_backing.rawAlloc(len, alignment, ret_addr);
if (comptime @import("builtin").mode == .Debug) {
if (r != null) __koru_leak_count += 1;
}
return r;
}
fn __koru_resize(ctx: *anyopaque, memory: []u8, alignment: @import("std").mem.Alignment, new_len: usize, ret_addr: usize) bool {
_ = ctx;
return __koru_backing.rawResize(memory, alignment, new_len, ret_addr);
}
fn __koru_remap(ctx: *anyopaque, memory: []u8, alignment: @import("std").mem.Alignment, new_len: usize, ret_addr: usize) ?[*]u8 {
_ = ctx;
return __koru_backing.rawRemap(memory, alignment, new_len, ret_addr);
}
fn __koru_free(ctx: *anyopaque, memory: []u8, alignment: @import("std").mem.Alignment, ret_addr: usize) void {
_ = ctx;
__koru_backing.rawFree(memory, alignment, ret_addr);
if (comptime @import("builtin").mode == .Debug) {
__koru_leak_count -= 1;
}
}
const __koru_vtable = @import("std").mem.Allocator.VTable{ .alloc = __koru_alloc, .resize = __koru_resize, .remap = __koru_remap, .free = __koru_free };
pub fn koru_allocator() @import("std").mem.Allocator {
return .{ .ptr = undefined, .vtable = &__koru_vtable };
}
pub inline fn __koru_intcast(comptime T: type, x: anytype) T {
if (comptime (@import("builtin").mode == .Debug or @import("builtin").mode == .ReleaseSafe))
return @as(T, @intCast(x));
const dst = @typeInfo(T);
const src = @typeInfo(@TypeOf(x));
if (comptime (dst == .int and src == .int and dst.int.bits == src.int.bits and dst.int.signedness != src.int.signedness))
return @as(T, @bitCast(x));
return @as(T, @intCast(x));
}
pub fn koru_leak_check() void {
if (comptime @import("builtin").mode != .Debug) return;
if (__koru_leak_count == 0) return;
if (comptime @import("builtin").target.os.tag == .freestanding) {
if (comptime @import("builtin").cpu.arch == .wasm32 or @import("builtin").cpu.arch == .wasm64) {
@panic("KORU LEAK CHECK FAILED: the produced program leaked");
} else {
const __klc = struct { extern var stdout: ?*anyopaque; extern fn fputs(__s: [*:0]const u8, __st: ?*anyopaque) c_int; };
var __lb: [128]u8 = undefined;
const __lm = "KORU LEAK CHECK FAILED: allocations still outstanding at end of run: ";
@memcpy(__lb[0..__lm.len], __lm);
var __ln: usize = __lm.len;
var __lv = __koru_leak_count;
var __ld: [20]u8 = undefined;
var __lk: usize = 0;
while (__lv > 0) : (__lk += 1) { __ld[__lk] = @intCast('0' + __lv % 10); __lv /= 10; }
for (0..__lk) |__li| { __lb[__ln] = __ld[__lk - 1 - __li]; __ln += 1; }
__lb[__ln] = '\n'; __ln += 1; __lb[__ln] = 0;
_ = __klc.fputs(@as([*:0]const u8, @ptrCast(&__lb)), __klc.stdout);
@trap();
}
} else {
@import("std").debug.print("KORU LEAK CHECK FAILED: the produced program leaked (trace above)\n", .{});
@import("std").process.exit(1);
}
}
pub const main_module = struct {
// std/store: plural store 'box' created (SoA cell + insert/query/write/take/stripe units); fields n: i64
// >>> FLOW: tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:39 ~input:__store_insertf_box()
pub fn flow0() void {
const result_0 = main_module.__store_insertf_box_event.handler(.{ .n = 7, .__site_line = 39 });
switch (result_0) {
// >>> BRANCH: tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:40 | row _auto_6 |>
.row => |_| {
},
// >>> BRANCH: tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:41 | full |>
.full => {
},
}
}
pub const shout_event = struct {
pub const Input = struct {
d: i64,
};
pub const Output = void;
pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
return __koru_handler_impl(__koru_event_input.d);
}
fn __koru_handler_impl(__koru_p_0: i64) @This().Output {
const __koru_event_input: @This().Input = .{ .d = __koru_p_0 };
// >>> PROC: shout [tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:44]
const d = __koru_event_input.d;
_ = &d;
_ = &__koru_event_input;
{
for (0..main_module.__koru_store_box.len) |__koru_si| {
const __koru_srf_r_L45_n = main_module.__koru_store_box.n[__koru_si];
_ = &__koru_srf_r_L45_n;
main_module.__store_sweepbody_box_L45_690_234_impl_param_not_captured_into_sweep_arm_input_7b1b0a_event.handler(.{ .__koru_srf_r_L45_n = __koru_srf_r_L45_n, .d = d, .__koru_sdix_r_L45 = __koru_si });
}
}
return;
}
};
// >>> FLOW: tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:47 ~input:shout()
pub fn flow1() void {
_ = main_module.shout_event.handler(.{ .d = 5 });
}
pub fn koru_start_flow() void {
const result_0 = koru_koru.start_event.handler(.{ });
const result_0_done = result_0.done;
_ = &result_0_done;
}
pub fn koru_end_flow() void {
const result_0 = koru_koru.end_event.handler(.{ });
const result_0_done = result_0.done;
_ = &result_0_done;
}
const __KoruStoreT_box = struct {
n: [4]i64 = undefined,
len: usize = 0,
};
var __koru_store_box: __KoruStoreT_box = .{};
const __KoruStoreRow_box = struct { n: i64 };
pub const __store_insertf_box_event = struct {
pub const Input = struct {
n: i64,
__site_line: i64,
};
pub const Output = union(enum(u8)) {
row: i64,
full: struct {
},
};
pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
return __koru_handler_impl(__koru_event_input.n, __koru_event_input.__site_line);
}
fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64) @This().Output {
const __koru_event_input: @This().Input = .{ .n = __koru_p_0, .__site_line = __koru_p_1 };
// >>> PROC: __store_insertf_box [tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:37]
const n = __koru_event_input.n;
const __site_line = __koru_event_input.__site_line;
_ = &n;
_ = &__site_line;
_ = &__koru_event_input;
if (__koru_store_box.len >= 4) return .{ .full = .{} };
if (__koru_store_box.len >= 4) @panic("std/store: store 'box' is full (capacity 4) - declared capacity and the `| full` branch are pinned at 690_011");
const __koru_new_row = __koru_store_box.len;
__koru_store_box.n[__koru_new_row] = n;
__koru_store_box.len += 1;
return .{ .row = @as(i64, @intCast(__koru_new_row)) };
}
};
pub const __store_apply_box_event = struct {
pub const Input = struct {
row: usize,
field: i64,
value_0: i64,
};
pub const Output = union(enum(u8)) {
n: i64,
};
pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
return __koru_handler_impl(__koru_event_input.row, __koru_event_input.field, __koru_event_input.value_0);
}
fn __koru_handler_impl(__koru_p_0: usize, __koru_p_1: i64, __koru_p_2: i64) @This().Output {
const __koru_event_input: @This().Input = .{ .row = __koru_p_0, .field = __koru_p_1, .value_0 = __koru_p_2 };
// >>> PROC: __store_apply_box [tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:37]
const row = __koru_event_input.row;
const field = __koru_event_input.field;
const value_0 = __koru_event_input.value_0;
_ = &row;
_ = &field;
_ = &value_0;
_ = &__koru_event_input;
const __koru_r: usize = row;
return switch (field) {
0 => blk: { __koru_store_box.n[__koru_r] = value_0; break :blk .{ .n = value_0 }; },
else => unreachable,
};
}
};
pub const __store_sweepbody_box_L45_690_234_impl_param_not_captured_into_sweep_arm_input_7b1b0a_event = struct {
pub const Input = struct {
__koru_srf_r_L45_n: i64,
d: i64,
__koru_sdix_r_L45: usize,
};
pub const Output = void;
pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
return __koru_handler_impl(__koru_event_input.__koru_srf_r_L45_n, __koru_event_input.d, __koru_event_input.__koru_sdix_r_L45);
}
fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64, __koru_p_2: usize) @This().Output {
const __koru_event_input: @This().Input = .{ .__koru_srf_r_L45_n = __koru_p_0, .d = __koru_p_1, .__koru_sdix_r_L45 = __koru_p_2 };
// >>> SUBFLOW: tests/regression/600_STDLIB/690_STORE/690_234_impl_param_not_captured_into_sweep_arm/input.k:44
const __koru_srf_r_L45_n = __koru_event_input.__koru_srf_r_L45_n;
const d = __koru_event_input.d;
const __koru_sdix_r_L45 = __koru_event_input.__koru_sdix_r_L45;
_ = &__koru_srf_r_L45_n;
_ = &d;
_ = &__koru_sdix_r_L45;
_ = &__koru_event_input;
(struct { fn __kout(__fd: i32, __b: []const u8) void { if (@import("builtin").os.tag == .freestanding) { const __kc = struct { extern var stdout: ?*anyopaque; extern var stderr: ?*anyopaque; extern fn fputs(__s: [*:0]const u8, __st: ?*anyopaque) c_int; }; var __kt: [4096]u8 = undefined; for (0..(__b.len + __kt.len - 2) / (__kt.len - 1)) |__ki| { const __kn = @min(__kt.len - 1, __b.len - __ki * (__kt.len - 1)); @memcpy(__kt[0..__kn], __b[__ki * (__kt.len - 1)..][0..__kn]); __kt[__kn] = 0; @import("std").mem.doNotOptimizeAway(__kc.fputs(@as([*:0]const u8, @ptrCast(&__kt)), if (__fd == 2) __kc.stderr else __kc.stdout)); } } else { @import("std").mem.doNotOptimizeAway(@import("std").posix.write(__fd, __b) catch @as(usize, 0)); } } fn __kw(comptime __f: []const u8, __a: anytype) void { var __kb: [65536]u8 = undefined; const __ks = @import("std").fmt.bufPrint(&__kb, __f, __a) catch __kb[0..0]; __kout(1, __ks); } }).__kw("{d} {d}\n", .{__koru_srf_r_L45_n, d});
}
};
};
pub const koru_koru = struct {
pub const start_event = struct {
pub const Input = struct {
};
pub const Output = union(enum(u8)) {
done: struct {
},
};
pub fn handler(__koru_event_input: @This().Input) @This().Output {
_ = &__koru_event_input;
return .{ .done = .{} };
}
};
pub const end_event = struct {
pub const Input = struct {
};
pub const Output = union(enum(u8)) {
done: struct {
},
};
pub fn handler(__koru_event_input: @This().Input) @This().Output {
_ = &__koru_event_input;
return .{ .done = .{} };
}
};
};
pub fn main() void {
main_module.koru_start_flow();
main_module.flow0();
main_module.flow1();
main_module.koru_end_flow();
if (comptime @import("builtin").mode == .Debug) koru_leak_check();
}
test {
@import("std").testing.refAllDeclsRecursive(@This());
}
Emitted C# source
static class main_module {
public static void __koru_stdout_write(dynamic s) => global::System.Console.Out.Write(s);
public static void __koru_stderr_write(dynamic s) => global::System.Console.Error.Write(s);
// The mutable handle carrier — `*String`-style resources are
// `new __KoruBox { data = … }` because C# anonymous types are
// read-only: `s.data = …` (std/string append/clear, handle
// mutation generally) needs a settable member.
public class __KoruBox { public dynamic data; }
// Textification for `{{ … }}` operands: C# bool ToStrings as
// `True` where Koru prints `true`, and the operand's static type
// is unknown at this boundary — a `(x) is bool` inline test would
// be a compile error on statically-typed operands instead. Generic
// on purpose: `dynamic` boxed every value-type operand — measured
// ~1s/10M elements on 012_threat_scanner — while T specializes to
// the operand's own ToString() with no box.
public static string __koru_str<T>(T v) => v is bool b ? (b ? "true" : "false") : v?.ToString();
// std/store: plural store 'box' created (SoA cell + insert/query/write/take/stripe units); fields n: i64
static class __koru_store_box {
public static long[] n = new long[4];
public static long len = 0;
public static long __koru_brand = -1;
}
public static class shout_event {
public struct Input {
public long d;
}
public static dynamic handler(Input __koru_input) {
var d = __koru_input.d;
{
for (var __koru_si = 0; __koru_si < __koru_store_box.len; __koru_si++) {
var __koru_srf_r_L45_n = __koru_store_box.n[__koru_si];
main_module.__store_sweepbody_box_L45_690_234_impl_param_not_captured_into_sweep_arm_input_7b1b0a_event.handler(new main_module.__store_sweepbody_box_L45_690_234_impl_param_not_captured_into_sweep_arm_input_7b1b0a_event.Input { __koru_srf_r_L45_n = __koru_srf_r_L45_n, d = d, __koru_sdix_r_L45 = __koru_si });
}
}
return default;
}
}
public static class __store_insertf_box_event {
public struct Input {
public long n;
public long __site_line;
}
public struct Output {
public string tag;
public long row;
public dynamic full;
}
public static Output handler(Input __koru_input) {
var n = __koru_input.n;
var __site_line = __koru_input.__site_line;
if (__koru_store_box.len >= 4) return new Output { tag = "full", full = new { } };
if (__koru_store_box.len >= 4) throw new global::System.Exception("std/store: store 'box' is full (capacity 4) - declared capacity and the `| full` branch are pinned at 690_011");
long __koru_new_row = __koru_store_box.len;
__koru_store_box.n[__koru_new_row] = n;
__koru_store_box.len += 1;
return new Output { tag = "row", row = __koru_new_row };
return default;
}
}
public static class __store_apply_box_event {
public struct Input {
public long row;
public long field;
public long value_0;
}
public struct Output {
public string tag;
public long n;
}
public static Output handler(Input __koru_input) {
var row = __koru_input.row;
var field = __koru_input.field;
var value_0 = __koru_input.value_0;
var __koru_r = row;
switch (field) {
case 0: { __koru_store_box.n[__koru_r] = value_0; return new Output { tag = "n", n = value_0 }; }
}
throw new global::System.Exception("__store_apply_box: field index " + field + " is not a column of store 'box'");
return default;
}
}
public static class __store_sweepbody_box_L45_690_234_impl_param_not_captured_into_sweep_arm_input_7b1b0a_event {
public struct Input {
public long __koru_srf_r_L45_n;
public long d;
public long __koru_sdix_r_L45;
}
public static dynamic handler(Input __koru_input) {
var __koru_srf_r_L45_n = __koru_input.__koru_srf_r_L45_n;
var d = __koru_input.d;
var __koru_sdix_r_L45 = __koru_input.__koru_sdix_r_L45;
__koru_stdout_write("" + __koru_str(__koru_srf_r_L45_n) + " " + __koru_str(d) + "\n");
return default;
}
}
public static class std_io_print_ln_event {
public struct Input {
public dynamic expr;
public dynamic invocation;
public dynamic item;
public dynamic program;
public dynamic reporter;
public dynamic allocator;
}
public static dynamic handler(Input __koru_input) {
var expr = __koru_input.expr;
var invocation = __koru_input.invocation;
var item = __koru_input.item;
var program = __koru_input.program;
var reporter = __koru_input.reporter;
var allocator = __koru_input.allocator;
throw new global::System.Exception("ln: [transform] tor is lowered at compile time and must never be called");
}
}
public static void flow0() {
var result_0 = main_module.__store_insertf_box_event.handler(new __store_insertf_box_event.Input { n = (long)(7), __site_line = (long)(39)});
if (result_0.tag == "row") {
var _auto_6 = result_0.row;
}
if (result_0.tag == "full") {
}
}
public static void flow1() {
{
var __koru_p_d = (long)(5);
{
for (var __koru_si = 0; __koru_si < __koru_store_box.len; __koru_si++) {
var __koru_srf_r_L45_n = __koru_store_box.n[__koru_si];
main_module.__store_sweepbody_box_L45_690_234_impl_param_not_captured_into_sweep_arm_input_7b1b0a_event.handler(new main_module.__store_sweepbody_box_L45_690_234_impl_param_not_captured_into_sweep_arm_input_7b1b0a_event.Input { __koru_srf_r_L45_n = __koru_srf_r_L45_n, d = __koru_p_d, __koru_sdix_r_L45 = __koru_si });
}
}
}
}
}
static class Program {
static void Main() {
main_module.flow0();
main_module.flow1();
}
}
Flows
flow ~new click a branch to expand · @labels scroll to their anchor
new (box, capacity: 4, source: n: i64)
flow ~insert click a branch to expand · @labels scroll to their anchor
insert (box, source: n: 7)
subflow ~shout click a branch to expand · @labels scroll to their anchor
query (box)
flow ~shout click a branch to expand · @labels scroll to their anchor
shout (d: 5)
Test Configuration
MUST_RUN LANGUAGES: zig cs