{-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE GeneralizedNewtypeDeriving #-} {-# LANGUAGE TypeFamilies #-} -------------------------------------------------------------------- -- | -- License : BSD3 -- Stability : experimental -- Portability: type-families, generalized newtype deriving -- -- This module provides a 'VarInt' wrapper with a 'Serial' instance -- that generates base-128 variable-width ints. Values are encoded 7 -- bits at a time, with the most significant being a continuation bit. -- Thus, the numbers from 0 to 127 require only a single byte to -- encode, those from 128 to 16383 require two bytes, etc. -- -- This format is taken from Google's /Protocol Buffers/, which -- provides a bit more verbiage on the encoding: -- <https://developers.google.com/protocol-buffers/docs/encoding#varints>. -------------------------------------------------------------------- module Data.Bytes.VarInt ( VarInt(..) ) where import Data.Bits import Data.Bytes.Signed newtype VarInt n = VarInt { unVarInt :: n } deriving (Eq, Ord, Show, Enum, Num, Integral, Bounded, Real, Bits) type instance Unsigned (VarInt n) = VarInt (Unsigned n) type instance Signed (VarInt n) = VarInt (Signed n)