# Pastebin c3R2f7SH

metSrcs :: Fold MetricType Text
metSrcs = folding $ \case
  DoubleMetric m -> foldMetric m
  IntMetric m -> foldMetric m
  where
    foldMetric :: Metric a -> Set Text
    foldMetric (Metric _ _ readings) = foldMap (\(Reading _ texts _) -> texts) readings