How can I feed a top-level CUE value into an expression during export?

[seh]

Suppose I have CUE file with the following content:

[
	{
		a: 1
	},
	{
		b: 2
	},
]

It's a top-level list, not a struct with any field names.

Suppose I'd like to export it as a multi-document YAML stream. Ideally I'd be able to refer to this top-level value in a command like this:

cue export list.cue --out=text --expression='yaml.MarshalStream($)'

Here I used the identifier $ in an appeal to Jsonnet, as some way to refer to the top-level value, but of course $ is not understood by CUE.

I experimented with using the --path and --with-context flags, to no avail.

[cueckoo]

This discussion has been migrated to cue-lang/cue#1054.

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