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