051 union with consume marker

✓ Passing This code compiles and runs correctly.

Code

~import app/handle
~app/handle:open()
| opened h1 |> app/handle:finalize(h: h1)
~app/handle:open()
| opened h1 |> app/handle:start-close(h: h1)
    | closing h2 |> app/handle:finalize(h: h2)

input.kz

Actual

Opening handle
Finalizing handle: 42
Opening handle
Starting close: 42
Finalizing handle: 42

Expected output

Opening handle
Finalizing handle: 42
Opening handle
Starting close: 42
Finalizing handle: 42

Imported Files

// Library module: handle
// Demonstrates phantom state unions - events that accept multiple states

const std = @import("std");

// Handle type with phantom states
const Handle = struct {
    id: i32,
};

// Open a handle - produces obligation (must be finalized)
~pub event open {}
| opened *Handle<opened!>

~proc open|zig {
    std.debug.print("Opening handle\n", .{});
    const allocator = std.heap.page_allocator;
    const h = allocator.create(Handle) catch unreachable;
    h.* = Handle{ .id = 42 };
    return .{ .opened = h };
}

// Start closing - explicitly discharges opened! and produces closing! obligation
~pub event start-close { h: *Handle<!opened> }
| closing *Handle<closing!>

~proc start-close|zig {
    std.debug.print("Starting close: {d}\n", .{h.id});
    return .{ .closing = h };
}

// Finalize - accepts EITHER opened OR closing, discharging whichever obligation exists
~pub event finalize { h: *Handle<!opened|closing> }

~proc finalize|zig {
    std.debug.print("Finalizing handle: {d}\n", .{h.id});
    // Clean up the handle
}

handle.kz

Test Configuration

MUST_RUN

← 050 union accepts either state 052 escape field name mismatch →