NBT (named binary tag) serialization and deserialization.

This project was created because the old nbt package has had a 1-liner open issue preventing compilation for 2 years now at the time of writing, despite submitting a pull request to fix it.

While I was at it, I went ahead and changed the data structure to use konsumlamm's rrb-vector package instead of lists or unboxed arrays for more well-rounded asymptotics.

StrictData is also turned on, and some functions are exported for reading/writing NBT files that remove some of the old boilerplate code.

named-binary-tag

A replacement for the old nbt package, because that one has been defunct for 2 years due to missing a single-line fix.

There are also a few improvements(?) made while I was at it:

• You can choose between a version with or without label maps using MapNbt or Nbt' respectively.
• Uses konsumlamm's rrb-vector package instead of a mix of lists and unboxed arrays for more well-rounded asymptotics.
• StrictData is enabled.
• Names of types and constructors are shortened a bit, with the reasoning that you should really be using qualified access for most of them.
• The code is shorter and better documented now (not that it really needed any documentation...)
• Less boilerplate is required to use it, at the expense of having zlib as a dependency. See below.

Usage

import Data.Nbt qualified as Nbt
import Data.Serialize

main :: IO ()
main = do
  shouldBeNbt <- Nbt.readCompressed "level.dat" :: IO (Either String Nbt') -- see also "Nbt.readUncompressed"
  case shouldBeNbt of
    Left err -> putStrLn err
    Right nbt -> do
      print nbt
      Nbt.writeCompressed "anotherlevel.dat" nbt -- see also "Nbt.writeUncompressed"

Possible Future Work

• Drop the cereal dependency and do bytestring parsing directly.
• Conversion to/from SNBT.
• Conversion to/from JSON.