Reference of a field defined in a "parent" definition not found

[PierreR]

I don't understand why in the following snippet I need to redefine a to make it works:

#ServicePort: {
	a: string
	name: string
}

#ServicePort: {
        a: string // error if I remove this line
	name: "\(a)"
}

port: #ServicePort & { a: "8080" }

https://tip.cuelang.org/play/?id=F6u1b8CNGSO#cue@export@cue

The real context is to be able to automatically generate the name of #ServicePort from the protocol and the port defined in the generated kubernetes schema (cue.mod/gen directory). I would do this in the same folder hierarchy in cue.mod/usr):

#ServicePort: {
	protocol: *"TCP" | #enumProtocol
	port: int32 // error if I remove this line but why ?
	name: "\(strings.ToLower(protocol))-\(port)"
}

Thanks for your help.

[seh]

Introducing a value alias seems to work.

[PierreR]

@seh Thanks. I will a value alias then.

I would love to understand what's going on exactly.

[seh]

It is interesting—and you probably noticed—that it works as you expected when there's only one definition involved.

[myitcv]

From the spec:

The scope of a field, alias or let identifier declared inside a struct literal is the innermost containing block.

My understanding is therefore that the scope of a is restricted to the containing braces in each case.

The value alias is exactly how I would solve this too, given the use case you describe @PierreR

[cueckoo]

This discussion has been migrated to cue-lang/cue#957.

For more details about CUE's migration to a new home, please see cue-lang/cue#1078.