061 phantom autodispose

// Test: Auto-discharge for phantom obligations
//
// Tests that the compiler automatically inserts cleanup
// when [allocated!] obligation is not manually discharged

~import "$std/io"

const std = @import("std");

pub const Resource = struct {
    data: []const u8,
    allocator: std.mem.Allocator,
};

~pub event create_resource { name: []const u8 }
| created *Resource[allocated!]

~proc create_resource {
    const alloc = std.heap.page_allocator;
    const data = std.fmt.allocPrint(alloc, "Resource: {s}", .{name}) catch unreachable;
    const res = alloc.create(Resource) catch unreachable;
    res.* = .{ .data = data, .allocator = alloc };
    return .{ .created = res };
}

~pub event destroy_resource { res: *Resource[!allocated] }
| destroyed

~proc destroy_resource {
    std.debug.print("  Auto-discharge called!\n", .{});
    res.allocator.free(res.data);
    std.heap.page_allocator.destroy(res);
    return .{ .destroyed = .{} };
}

// Helper to use the resource
~pub event use_resource { res: *Resource }
| used

~proc use_resource {
    std.debug.print("  Using: {s}\n", .{res.data});
    return .{ .used = .{} };
}

// Test: Create resource, use it, but DON'T manually destroy
// Auto-discharge should insert destroy_resource
~std.io:print.ln("Test start")
~create_resource(name: "AutoDisposed")
| created r |>
    use_resource(res: r)
    | used |> _
    // Obligation [allocated!] should trigger auto-discharge here

~std.io:print.ln("Test done")