def fmt.rate
import emerging-ezaudio@0.4.0.0/src/wav.bend as Wavimport Base
89def fmt.rate(ok: Bool, +kind: U32, +ch: U32, +rate: U32) -> Maybe<&2, Fm>:
90 match ok:
91 case True{}:
92 Some{Fm{kind, ch, rate}}
93 case False{}:
94 None{}