Enforcing unique enum values in a CUE List Schema

[EdenCore]

Hello,

Does someone know how to convert the following definition ?

boot_device_order_list:
  description: >
      Indicates the order of device types in which VM
      should try to boot from. If boot device order is
      not provided the system will decide appropriate
      boot device order.
  items:
    type: string
    x-ntnx-enum:
      - CDROM
      - DISK
      - NETWORK
  type: array

I have tried the following naive approach:

values: "CDROM" | "DISK" | "NETWORK"
#boot_device_order_list: [...values]
#boot_device_order_list & ["CDROM"]
//conflicting values ["CDROM"] and {values:("CDROM"|"DISK"|"NETWORK"),#boot_device_order_list:[...values],(#boot_device_order_list & ["CDROM"])} (mismatched types list and struct):
  -:1:1
  -:3:27

Also please note that the list size must be 1=< and =<3 . Each enum value can only be used once.

[EdenCore]

This is a little bit closer to what I am looking for. But unfortunately, the known issue is preventing me to ensure no duplicates...

#boot_order_list: [ _,_,_ & =~ "CDROM|DISK|NETWORK"]

[infogulch]

Maybe convert the list values to struct keys and assert the length still matches?

[EdenCore]

Hi, I do not really understand your idea. Can you give an example ?

[infogulch]

Maybe something like this; I wrapped it as a "function pattern":

https://cuelang.org/play/?id=n4JYFMOSe49#w=function&i=cue&f=eval&o=cue

[EdenCore]

That's clever. Thank's a lot for your help !
For future reference, here is the working code:

#bootDevice: "CDROM" | "DISK" | "NETWORK"

#bootConfig: {
  boot_device_order_list: [#bootDevice, #bootDevice, #bootDevice]
  #uniqueDevices: {
    for device in boot_device_order_list {
      (device): null
    }
  }
  #check: len(boot_device_order_list)
  #check: len(#uniqueDevices)
}

should_work: {
"1": #bootConfig & { boot_device_order_list: ["DISK", "CDROM", "NETWORK"] }
"2": #bootConfig & { boot_device_order_list: ["CDROM", "DISK", "NETWORK"] }
}
should_not_work: #bootConfig & { boot_device_order_list: ["ISK", "CDROM", "NETWORK"] }

should_not_work_either: #bootConfig & { boot_device_order_list: ["CDROM", "NETWORK"] }

And the output :

should_not_work.boot_device_order_list.0: 3 errors in empty disjunction:
should_not_work.boot_device_order_list.0: conflicting values "CDROM" and "ISK":
    -:1:14
    -:4:28
    -:18:18
    -:18:59
should_not_work.boot_device_order_list.0: conflicting values "DISK" and "ISK":
    -:1:24
    -:4:28
    -:18:18
    -:18:59
should_not_work.boot_device_order_list.0: conflicting values "NETWORK" and "ISK":
    -:1:33
    -:4:28
    -:18:18
    -:18:59

[infogulch]

Maybe even easier is the builtin list.UniqueItems 🤦‍♂️

https://cuelang.org/docs/howto/use-list-uniqueitems-as-a-field-validator/

[EdenCore]

Hahaha. Essentially both solution share the same principles but indeed the builtin function is cleaner