numbers := [1, 2, 3]
more_numbers := [0, ...numbers, 4]

codes := ['ok' => 200, 'missing' => 404]
more_codes := [...codes, 'failed' => 500]

empty_numbers: []i32: []
empty_codes: [str]i32: []
optional_numbers: []i32?: nil
optional_elements: []{i32?}: [nil, 1->|.some]

Options :: &{
    name: str: 'default'
    count: i32 = 0
}

defaults := &Options.{}
overridden := &Options.{ ...defaults; count = 2 }
anonymous := &.{ label: 'value'; count = 1 }