StaticformatStaticregisterRegister a custom filter usable as {{ x | name }} (with optional
args: {{ x | name: 'arg' }}). Filters that return Mml fragments
compose with the Mml-aware output handler; raw-string returns get
five-entity escaping.
One-shot: parse and render. Use
Prose.parse+renderfor hot paths where the template source is constant — the compiled form skips re-parsing on every call.