Kawaii-Parser-4.0.0: Parser/Locations.hs

{-|
Description: Locations.

* Locations.
-}
module Parser.Locations (
  Location,
  With_location (..),
  init_location,
  next_char,
  next_line,
  write_location) where
  deriving instance Eq Location
  deriving instance Ord Location
  deriving instance Show Location
  deriving instance Show t => Show (With_location t)
  -- | Locations.
  data Location = Location Integer Integer
  -- | Add a location to any type.
  data With_location t = With_location Location t
  instance Monoid Location where
    mempty = init_location
  instance Semigroup Location where
    (<>) = max
  -- | First line, first character.
  init_location :: Location
  init_location = Location 1 1
  -- | Move one character to the right.
  next_char :: Location -> Location
  next_char (Location line char) = Location line (1 + char)
  -- | Move to the next line.
  next_line :: Location -> Location
  next_line (Location line _) = Location (1 + line) 1
  -- | Write the location.
  write_location :: Location -> String
  write_location (Location line char) = show line <> ":" <> show char