evaluateCheck

The ValidationResult a check's condition evaluates to.

A condition may be a call to one of the five validation functions or a DataBinding into the data model — the specification allows both, since an agent may compute a result server-side and send it down. Either way the value has to be shaped like a ValidationResult, and one that is not raises rather than being read as "invalid": a renderer cannot tell a failed check from a malformed one by looking at a false.