Set a field of a protobuf to Err type

[mneff-roblox]

Is there any way to do this?

Reading through the default type adapter it seems like no, but it'd be ideal if I could set individual fields to be errored.

For example if I could have a user proto with fields verified and age and write an expression user.verified or user.age > 18, it would be nice if I could mark only age as errored so that this can still evaluate to true if verified is true

I can already do this with a map but then lose out on type checking and stuff like that.

[TristonianJones]

Hi there,

You could do something like the following:

        env, err := cel.NewEnv(cel.Types(&User), cel.Variable("user", cel.ObjectType("User"))
        ast, iss := env.Compile(`user.verified || user.age > 18`)
        prg, err := env.Program(ast)

	unkVars, err := cel.PartialVars(
		map[string]any{
			"user": <user>,
		},
		cel.AttributePattern("user").QualString("age"),
	)
        out, _, err := prg.Eval(unkVars)

-Tristan

[mneff-roblox]

Do you think it makes sense to add a separate PartialActivation with a similar interface for errors? I have some loose hopes in the future to use unknown separately.

[TristonianJones]

The unknown is a bit like an error, but implies the data could become available. Are you trying to produce an error on access or set a field to error in an expression? Maybe you could mention more about your use case?

[mneff-roblox]

My eventual goal is to have a loop where I'm evaluating the expression to get unknowns, sending them off to be loaded, and reevaluating as data comes back with either success or errors, until the expression resolves to an error or value. I guess the weirdness is that my proto is the aggregation of multiple data loads, rather than being a single object thats either an error or a value.