Data.Text.Internal

Copyright	(c) 2008 2009 Tom Harper (c) 2009 2010 Bryan O'Sullivan (c) 2009 Duncan Coutts
License	BSD-style
Maintainer	[email protected]
Stability	experimental
Portability	GHC
Safe Haskell	None
Language	Haskell2010

Types
Construction
Safety
Code that must be here for accessibility
Utilities
Checked multiplication
Debugging

Description

A module containing private Text internals. This exposes the Text representation and low level construction functions. Modules which extend the Text system may need to use this module.

You should not use this module unless you are determined to monkey with the internals, as the functions here do just about nothing to preserve data invariants. You have been warned!

Types

Internally, the Text type is represented as an array of Word16 UTF-16 code units. The offset and length fields in the constructor are in these units, not units of Char.

Invariants that all functions must maintain:

Since the Text type uses UTF-16 internally, it cannot represent characters in the reserved surrogate code point range U+D800 to U+DFFF. To maintain this invariant, the safe function maps Char values in this range to the replacement character (U+FFFD, '�').
A leading (or "high") surrogate code unit (0xD800–0xDBFF) must always be followed by a trailing (or "low") surrogate code unit (0xDC00-0xDFFF). A trailing surrogate code unit must always be preceded by a leading surrogate code unit.

data Text Source

A space efficient, packed, unboxed Unicode text type.

Constructors

Text !Array !Int !Int

Instances

Instances details

IsList Text	Since: text-1.2.0.0
Instance details Defined in Data.Text Associated Types type Item Text Source Methods fromList :: [Item Text] -> Text Source fromListN :: Int -> [Item Text] -> Text Source toList :: Text -> [Item Text] Source
Eq Text
Instance details Defined in Data.Text Methods (==) :: Text -> Text -> Bool Source (/=) :: Text -> Text -> Bool Source
Data Text	This instance preserves data abstraction at the cost of inefficiency. We omit reflection services for the sake of data abstraction. This instance was created by copying the updated behavior of `Data.Set.Set` and `Data.Map.Map`. If you feel a mistake has been made, please feel free to submit improvements. The original discussion is archived here: could we get a Data instance for Data.Text.Text? The followup discussion that changed the behavior of `Set` and `Map` is archived here: Proposal: Allow gunfold for Data.Map, ...
Instance details Defined in Data.Text Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Text -> c Text Source gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Text Source toConstr :: Text -> Constr Source dataTypeOf :: Text -> DataType Source dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Text) Source dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Text) Source gmapT :: (forall b. Data b => b -> b) -> Text -> Text Source gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Text -> r Source gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Text -> r Source gmapQ :: (forall d. Data d => d -> u) -> Text -> [u] Source gmapQi :: Int -> (forall d. Data d => d -> u) -> Text -> u Source gmapM :: Monad m => (forall d. Data d => d -> m d) -> Text -> m Text Source gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Text -> m Text Source gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Text -> m Text Source
Ord Text
Instance details Defined in Data.Text Methods compare :: Text -> Text -> Ordering Source (<) :: Text -> Text -> Bool Source (<=) :: Text -> Text -> Bool Source (>) :: Text -> Text -> Bool Source (>=) :: Text -> Text -> Bool Source max :: Text -> Text -> Text Source min :: Text -> Text -> Text Source
Read Text
Instance details Defined in Data.Text Methods readsPrec :: Int -> ReadS Text Source readList :: ReadS [Text] Source readPrec :: ReadPrec Text Source readListPrec :: ReadPrec [Text] Source
Show Text
Instance details Defined in Data.Text.Show Methods showsPrec :: Int -> Text -> ShowS Source show :: Text -> String Source showList :: [Text] -> ShowS Source
IsString Text
Instance details Defined in Data.Text Methods fromString :: String -> Text Source
Semigroup Text	Non-orphan `Semigroup` instance only defined for `base-4.9.0.0` and later; orphan instances for older GHCs are provided by the semigroups package Since: text-1.2.2.0
Instance details Defined in Data.Text Methods (<>) :: Text -> Text -> Text Source sconcat :: NonEmpty Text -> Text Source stimes :: Integral b => b -> Text -> Text Source
Monoid Text
Instance details Defined in Data.Text Methods mempty :: Text Source mappend :: Text -> Text -> Text Source mconcat :: [Text] -> Text Source
PrintfArg Text	Only defined for `base-4.7.0.0` and later Since: text-1.2.2.0
Instance details Defined in Data.Text Methods formatArg :: Text -> FieldFormatter Source parseFormat :: Text -> ModifierParser Source
Binary Text	Since: text-1.2.1.0
Instance details Defined in Data.Text Methods put :: Text -> Put Source get :: Get Text Source putList :: [Text] -> Put Source
NFData Text
Instance details Defined in Data.Text Methods rnf :: Text -> () Source
type Item Text
Instance details Defined in Data.Text type Item Text = Char

Construction

text :: Array -> Int -> Int -> Text Source

Construct a Text without invisibly pinning its byte array in memory if its length has dwindled to zero.

textP :: Array -> Int -> Int -> Text Source

Deprecated: Use text instead

Safety

safe :: Char -> Char Source

Map a Char to a Text-safe value.

UTF-16 surrogate code points are not included in the set of Unicode scalar values, but are unfortunately admitted as valid Char values by Haskell. They cannot be represented in a Text. This function remaps those code points to the Unicode replacement character (U+FFFD, '�'), and leaves other code points unchanged.