✓
Passing This code compiles and runs correctly.
Code
// Cross-target dispatch under Koru's named-parameter rule. The effect handler
// `! tick i` sends its bound value to the `onTick` event, whose field is `slot`.
// Koru only supports NAMED parameters — a call's meaning must be derivable
// without context-hunting — so the dispatch is spelled `onTick(slot: i)`, never
// positionally. Both targets resolve the arg by name and print `hits=1`.
//
// HISTORY: this was a JS-target frontier pin (2026-06-01). It was written
// positionally as `onTick(i)`, which the Zig emitter bound BY INDEX while the JS
// `emitInlinePlainHandler` resolved BY FIELD-NAME only and aborted
// (UnsupportedConstruct) on the `i`/`slot` mismatch — a cross-target divergence.
// The punning wall (PARSE006) forecloses it at the frontend: a bare arg that
// doesn't pun to a parameter is rejected on EVERY target, so a positional
// mismatch can never reach an emitter. Labeled dispatch resolves by name
// identically on Zig and JS, so the old "make JS resolve positionally" fix is
// unnecessary — the rule closed the gap by construction. Green on both.
pub tor ticker { n: u64 }
! tick u64
pub tor onTick { slot: u64 }
pub tor report {}
ticker(n: 1)
! tick i |> onTick(slot: i)
report()
Supporting Files
// C# implementation facet. Tors are declared in input.k; this file holds
// the |cs proc bodies. Module state lives as statics on KoruHost pulled
// into file scope by `using static` — C# has no file-scope variables.
using static KoruHost;
static class KoruHost {
public static ulong hits = 0;
}
~proc ticker|cs {
for (ulong i = 0; i < n; i++) {
tick(i);
}
}
~proc onTick|cs { hits = hits + 1; }
~proc report|cs { __koru_stdout_write("hits=" + hits + "\n"); }
Actual
hits=1
Expected output
✓ Zig✓ JavaScript✓ C#hits=1
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 {
const std = @import("std");
var hits: u64 = 0;
pub const ticker_event = struct {
pub const Input = struct {
n: u64,
};
pub const Output = void;
pub fn handler(__koru_event_input: @This().Input, comptime __H: type) @This().Output {
const tick = __H.tick;
_ = &tick;
// >>> PROC: ticker [tests/regression/400_RUNTIME_FEATURES/400_112_effect_branch_arg_name_mismatch_cross_target/input.kz:5]
const n = __koru_event_input.n;
_ = &n;
_ = &__koru_event_input;
var i: u64 = 0;
while (i < n) : (i += 1) {
tick(i);
}
}
};
pub const onTick_event = struct {
pub const Input = struct {
slot: u64,
};
pub const Output = void;
pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
return __koru_handler_impl(__koru_event_input.slot);
}
fn __koru_handler_impl(__koru_p_0: u64) @This().Output {
const __koru_event_input: @This().Input = .{ .slot = __koru_p_0 };
// >>> PROC: onTick [tests/regression/400_RUNTIME_FEATURES/400_112_effect_branch_arg_name_mismatch_cross_target/input.kz:12]
const slot = __koru_event_input.slot;
_ = &slot;
_ = &__koru_event_input;
hits = hits + 1; _ = &slot;
}
};
pub const report_event = struct {
pub const Input = struct {
};
pub const Output = void;
pub fn handler(__koru_event_input: @This().Input) @This().Output {
// >>> PROC: report [tests/regression/400_RUNTIME_FEATURES/400_112_effect_branch_arg_name_mismatch_cross_target/input.kz:13]
_ = &__koru_event_input;
std.debug.print("hits={d}\n", .{hits});
}
};
// >>> FLOW: tests/regression/400_RUNTIME_FEATURES/400_112_effect_branch_arg_name_mismatch_cross_target/input.k:21 ~input:ticker()
pub fn flow0() void {
{
const n = (1); _ = &n;
var i: u64 = 0;
while (i < n) : (i += 1) {
{ _ = main_module.onTick_event.handler(.{ .slot = i });
}
}
}
}
// >>> FLOW: tests/regression/400_RUNTIME_FEATURES/400_112_effect_branch_arg_name_mismatch_cross_target/input.k:23 ~input:report()
pub fn flow1() void {
_ = main_module.report_event.handler(.{ });
}
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;
}
};
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
using static KoruHost;
static class KoruHost {
public static ulong hits = 0;
}
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();
public static class ticker_event {
public struct Input {
public ulong n;
}
public interface IOps {
void tick(ulong __koru_arg);
}
public static dynamic handler<H>(Input __koru_input, H ops) where H : struct, IOps {
void tick(ulong __koru_arg) => ops.tick(__koru_arg);
var n = __koru_input.n;
for (ulong i = 0; i < n; i++) {
tick(i);
}
return default;
}
}
public static class onTick_event {
public struct Input {
public ulong slot;
}
public static dynamic handler(Input __koru_input) {
var slot = __koru_input.slot;
var hits = KoruHost.hits;
hits = hits + 1;
KoruHost.hits = hits;
return default;
}
}
public static class report_event {
public struct Input {
}
public static dynamic handler(Input __koru_input) {
var hits = KoruHost.hits;
__koru_stdout_write("hits=" + hits + "\n");
KoruHost.hits = hits;
return default;
}
}
public static void flow0() {
var __koru_handlers_0 = new __koru_handlers_0 { __koru_fn_tick = (__koru_arm_1) => {
var i = __koru_arm_1;
{
var __koru_p_slot = (ulong)(i);
hits = hits + 1;
}
return null;
}, };
main_module.ticker_event.handler(new ticker_event.Input { n = (ulong)(1)}, __koru_handlers_0);
}
public static void flow1() {
{
__koru_stdout_write("hits=" + hits + "\n");
}
}
struct __koru_handlers_0 : ticker_event.IOps {
public global::System.Func<dynamic, dynamic> __koru_fn_tick;
public void tick(ulong __koru_arm_1) => __koru_fn_tick(__koru_arm_1);
}
}
static class Program {
static void Main() {
main_module.flow0();
main_module.flow1();
}
}
Test Configuration
MUST_RUN LANGUAGES: zig js cs