001 basic catchall

// Test 918: Optional Branches - Basic |? Catch-All
//
// Verifies:
// 1. Event with required and optional branches
// 2. |? catches optional branches generically
// 3. Required branches handled explicitly as usual

~import "$std/io"

// Event with both required and optional branches
~event process { value: u32 }
| success { result: u32 }        // REQUIRED: must be handled
| ?warning { msg: []const u8 }   // OPTIONAL: can be caught by |?
| ?debug { details: []const u8 } // OPTIONAL: can be caught by |?

~proc process {
    // When value > 100, return optional warning branch
    if (value > 100) {
        return .{ .warning = .{ .msg = "Value is large" } };
    }

    // When value is odd, return optional debug branch
    if (value % 2 == 1) {
        return .{ .debug = .{ .details = "Value is odd" } };
    }

    // Otherwise return required success branch
    return .{ .success = .{ .result = value * 2 } };
}

// Call 1: value=10 → even, <100 → success branch
~process(value: 10)
| success _ |> std.io:print.ln("GOT SUCCESS")
|? |> std.io:print.ln("GOT OPTIONAL")

// Call 2: value=150 → >100 → warning branch (caught by |?)
~process(value: 150)
| success _ |> std.io:print.ln("GOT SUCCESS")
|? |> std.io:print.ln("GOT OPTIONAL")

// Call 3: value=7 → odd → debug branch (caught by |?)
~process(value: 7)
| success _ |> std.io:print.ln("GOT SUCCESS")
|? |> std.io:print.ln("GOT OPTIONAL")