Unable to raise exception after checking a specific condition

[debuggerrr]

I want to raise an issue for suppose below example:
if len(a)>0 { raise exception }

How can be it done using CUE? I didn't find any specific example w.r.t raising an exception.

[slewiskelly]

I suppose you could do something like:

if len(a) > 0 {
	_err: _|_
}

But it wouldn't be an encouraged pattern.

I think maybe you are trying employ concepts and techniques from imperative, general-purpose, programming languages that don't apply to CUE.

In CUE, you would add a constrain to specify that a should contain (at least, exactly, or no more than) a specifc number of elements.

Using your specific example, you could use either of the following:

a: []

import "list"

a: [...string] & list.MaxItems(0)

a: [...string]

_ok: true & len(a) < 1

Choosing one over the other would depend on a specific situation, but the first two are likely suitable for the majority of cases.

[debuggerrr]

Okay, let me try this tomorrow. Thanks for the help though :)

[myitcv]

@debuggerrr can you provide a bit more information about what you're trying to do here?

How/where are you using CUE?

In a policy setting?