Types and are Values
Lists define arbitrary sequences of CUE values. A list can be closed or open ended. Open-ended lists may have some predefined elements, but may have additional, possibly typed elements.
In the example we define IP to be a list of 4 elements of type uint8, which is a predeclared value of >=0 & <=255. PrivateIP defines the IP ranges defined for private use. Note that as it is already defined to be an IP, the length of the list is already fixed at 4 and we do not have to specify a value for all elements. Also note that instead of writing ...uint8, we could have written ... as the type constraint is already already implied by IP.
The output contains a valid private IP address (myIP) and an invalid one (yourIP).
lists.cue:
IP: 4 * [ uint8 ] PrivateIP: IP PrivateIP: [10, ...uint8] | [192, 168, ...] | [172, >=16 & <=32, ...] myIP: PrivateIP myIP: [10, 2, 3, 4] yourIP: PrivateIP yourIP: [11, 1, 2, 3]
$ cue eval -i lists.cue
IP: [uint8, uint8, uint8, uint8] PrivateIP: [10, uint8, uint8, uint8] | [192, 168, uint8, uint8] | [172, >=16 & <=32, uint8, uint8] myIP: [10, 2, 3, 4] yourIP: _|_ // empty disjunction: [((10 & (int & >=0 & int & <=255)) & 11),((int & >=0 & int & <=255) & 1),((int & >=0 & int & <=255) & 2),((int & >=0 & int & <=255) & 3)]