{-# LANGUAGE TypeFamilies #-} {-# LANGUAGE FlexibleContexts #-} ----------------------------------------------------------------------------- -- | -- Module : Data.ByteString.Lazy.Lens -- Copyright : (C) 2012 Edward Kmett -- License : BSD-style (see the file LICENSE) -- Maintainer : Edward Kmett <ekmett@gmail.com> -- Stability : experimental -- Portability : non-portable -- -- Lenses for lazy bytestrings ---------------------------------------------------------------------------- module Data.ByteString.Lazy.Lens ( packedBytes, bytes , packedChars, chars ) where import Control.Lens import Data.ByteString.Lazy as Words import Data.ByteString.Lazy.Char8 as Char8 import Data.Word (Word8) -- | 'Data.ByteString.Lazy.pack' (or 'Data.ByteString.Lazy.unpack') a list of bytes into a 'ByteString' -- -- @'Data.ByteString.Lazy.pack' x = x '^.' 'packedBytes'@ -- -- @'Data.ByteString.Lazy.unpack' x = x '^.' 'from' 'packedBytes'@ packedBytes :: Simple Iso [Word8] ByteString packedBytes = iso Words.pack Words.unpack {-# INLINE packedBytes #-} -- | Traverse the individual bytes in a 'ByteString' -- -- @'bytes' = 'from' 'packedBytes' . 'itraversed'@ -- -- @'anyOf' 'bytes' ('==' 0x80) :: 'ByteString' -> 'Bool'@ bytes :: SimpleIndexedTraversal Int ByteString Word8 bytes = from packedBytes .> itraversed {-# INLINE bytes #-} -- | 'Data.ByteString.Lazy.Char8.pack' (or 'Data.ByteString.Lazy.Char8.unpack') a list of characters into a 'ByteString' -- -- When writing back to the 'ByteString' it is assumed that every 'Char' -- lies between '\x00' and '\xff'. -- -- @'Data.ByteString.Lazy.Char8.pack' x = x '^.' 'packedChars'@ -- -- @'Data.ByteString.Lazy.Char8.unpack' x = x '^.' 'from' 'packedChars'@ packedChars :: Simple Iso String ByteString packedChars = iso Char8.pack Char8.unpack {-# INLINE packedChars #-} -- | Traverse the individual bytes in a 'ByteString' as characters. -- -- When writing back to the 'ByteString' it is assumed that every 'Char' -- lies between '\x00' and '\xff'. -- -- @'chars' = 'from' 'packedChars' '.>' 'itraversed'@ -- -- @'anyOf' 'chars' ('==' \'c\') :: 'ByteString' -> 'Bool'@ chars :: SimpleIndexedTraversal Int ByteString Char chars = from packedChars .> itraversed {-# INLINE chars #-}