Sort-Object reports error "unexpected {"

[tomasbruckner]

This code

Get-ChildItem ".\" -Recurse |
    Select-Object @{n = '1'; e = { $_.Name.Split(".")[0] } }, @{n = '2'; e = { $_.Name.Split(".")[1] } }, @{n = '3'; e = { $_.Name.Split(".")[2] } }, @{n = '4'; e = { $_.Name.Split(".")[3] } }, @{n = 'full'; e = { $_.Name } } |
    Sort-Object { [int]$_.1 }, { [int]$_.2 }, { [int]$_.3 }, { [int]$_.4 } |
....

Show "unexpected {" but it works fine