{-# LANGUAGE CPP #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE TypeSynonymInstances #-} #ifdef TRUSTWORTHY {-# LANGUAGE Trustworthy #-} #endif ----------------------------------------------------------------------------- -- | -- Module : Data.Text.Lens -- Copyright : (C) 2012-14 Edward Kmett -- License : BSD-style (see the file LICENSE) -- Maintainer : Edward Kmett <ekmett@gmail.com> -- Stability : experimental -- Portability : non-portable -- ---------------------------------------------------------------------------- module Data.Text.Lens ( IsText(..) , unpacked , _Text ) where import Control.Lens import Data.Text as Strict import qualified Data.Text.Strict.Lens as Strict import Data.Text.Lazy as Lazy import qualified Data.Text.Lazy.Lens as Lazy import Data.Text.Lazy.Builder -- | Traversals for strict or lazy 'Text' class IsText t where -- | This isomorphism can be used to 'pack' (or 'unpack') strict or lazy 'Text'. -- -- @ -- 'pack' x ≡ x '^.' 'packed' -- 'unpack' x ≡ x '^.' 'from' 'packed' -- 'packed' ≡ 'from' 'unpacked' -- @ packed :: Iso' String t -- | Convert between strict or lazy 'Text' and a 'Builder'. -- -- @ -- 'fromText' x ≡ x '^.' 'builder' -- @ builder :: Iso' t Builder -- | Traverse the individual characters in strict or lazy 'Text'. -- -- @ -- 'text' = 'unpacked' . 'traversed' -- @ text :: IndexedTraversal' Int t Char text = unpacked . traversed {-# INLINE text #-} instance IsText String where packed = id {-# INLINE packed #-} text = indexing traverse {-# INLINE text #-} builder = Lazy.packed . builder {-# INLINE builder #-} -- | This isomorphism can be used to 'unpack' (or 'pack') both strict or lazy 'Text'. -- -- @ -- 'unpack' x ≡ x '^.' 'unpacked' -- 'pack' x ≡ x '^.' 'from' 'unpacked' -- @ -- -- This 'Iso' is provided for notational convenience rather than out of great need, since -- -- @ -- 'unpacked' ≡ 'from' 'packed' -- @ -- unpacked :: IsText t => Iso' t String unpacked = from packed {-# INLINE unpacked #-} -- | This is an alias for 'unpacked' that makes it clearer how to use it with @('#')@. -- -- @ -- '_Text' = 'from' 'packed' -- @ -- -- >>> _Text # "hello" :: Strict.Text -- "hello" _Text :: IsText t => Iso' t String _Text = from packed {-# INLINE _Text #-} instance IsText Strict.Text where packed = Strict.packed {-# INLINE packed #-} builder = Strict.builder {-# INLINE builder #-} text = Strict.text {-# INLINE text #-} instance IsText Lazy.Text where packed = Lazy.packed {-# INLINE packed #-} builder = Lazy.builder {-# INLINE builder #-} text = Lazy.text {-# INLINE text #-}