This paper introduces and investigates a family of metrics on sets of structures for formal languages, with a special focus on their application to sets of pointed Kripke models and modal logic, and, in extension, to dynamic epistemic logic. The metrics are generalizations of the Hamming distance applicable to countably infinite binary strings and, by extension, logical theories or semantic structures. We first study the topological properties of the resulting metric spaces. A key result provides sufficient conditions for spaces having the Stone property, i.e., being compact, totally disconnected and Hausdorff. Second, we turn to mappings, where it is shown that a widely used type of model transformations, product updates, give rise to continuous maps in the induced topology.