nested depth 4

// Depth 4 test: start |> +1 |> +2 |> +3 |> +4 → result (10+1+2+3+4 = 20)
const std = @import("std");

~event add_one { value: i32 } | done { result: i32 }
~proc add_one = done { result: value + 1 }

~event add_two { value: i32 } | done { result: i32 }
~proc add_two = done { result: value + 2 }

~event add_three { value: i32 } | done { result: i32 }
~proc add_three = done { result: value + 3 }

~event add_four { value: i32 } | done { result: i32 }
~proc add_four = done { result: value + 4 }

~event chain { start: i32 } | done { result: i32 }

~proc chain = add_one(value: start)
| done a |> add_two(value: a.result)
    | done b |> add_three(value: b.result)
        | done c |> add_four(value: c.result)
            | done d |> done { result: d.result }

pub fn main() void {
    const result = chain_event.handler(.{ .start = 10 });
    std.debug.print("{}\n", .{result.done.result});
}