ruleAboutDuration :: Rule
ruleAboutDuration = Rule
  { name = "about <duration>"
  , pattern =
    [ regex "(omkring|cirka|ca.|ca|runt)"
    , dimension Duration
    ]
  , prod = \tokens -> case tokens of
      (_:token:_) -> Just token
      _ -> Nothing
  }
ruleAboutDuration :: Rule
ruleAboutDuration = Rule
  { name = "about <duration>"
  , pattern =
    [ regex "(omkring|cirka|ca.|ca|runt)"
    , dimension Duration
    ]
  , prod = \tokens -> case tokens of
      (_:token:_) -> Just token
      _ -> Nothing
  }
ruleAboutDuration = Rule
  { name = "about <duration>"
  , pattern =
    [ regex "(omkring|cirka|ca.|ca|runt)"
    , dimension Duration
    ]
  , prod = \tokens -> case tokens of
      (_:token:_) -> Just token
      _ -> Nothing
  }