lib/Hcompta/Tag.hs

   1 {-# LANGUAGE TupleSections #-}
   2 module Hcompta.Tag where
   3
   4 import qualified Data.List.NonEmpty as NonEmpty
   5 import           Data.List.NonEmpty (NonEmpty(..))
   6 import           Data.Maybe (Maybe(..))
   7 import qualified Data.Text as Text
   8 import           Data.Text (Text)
   9 import           Prelude (Int)
  10
  11 -- * The 'Tag' type
  12
  13 -- | An 'Tag' is a non-empty list of 'Section'.
  14 type Tag     = (Path, Value)
  15 type Section = Text
  16 type Path    = NonEmpty Section
  17 type Value   = Text
  18
  19 -- | Return the 'Tag' formed by the given 'Path' and 'Value'.
  20 tag :: Path -> Value -> Tag
  21 tag = (,)
  22
  23 -- | Return the 'Value' formed by the given 'Section' and 'Section's.
  24 path :: Section -> [Section] -> Path
  25 path = (:|)
  26
  27 -- | Return the 'Value' of a 'Tag', if any.
  28 value :: Tag -> Maybe Value
  29 value (_, v) | Text.null v = Nothing
  30 value (_, v) = Just v
  31
  32 -- | Return the number of 'Section's in the given 'Tag'.
  33 depth :: Path -> Int
  34 depth = NonEmpty.length
  35
  36 -- | Return an 'Tag' from the given list.
  37 from_List :: [Section] -> Path
  38 from_List = NonEmpty.fromList