@@ -1,29 +1,48 @@
1−{-# LANGUAGE BangPatterns, Rank2Types #-}
1+{-# LANGUAGE BangPatterns, CPP, MagicHash, Rank2Types, UnboxedTuples #-}
2{-# OPTIONS_GHC -fno-warn-orphans #-}
2{-# OPTIONS_GHC -fno-warn-orphans #-}
3+#if __GLASGOW_HASKELL__ >= 702
4+{-# LANGUAGE Trustworthy #-}
6+#if __GLASGOW_HASKELL__ >= 708
7+{-# LANGUAGE TypeFamilies #-}
5-- Module : Data.Text
11-- Module : Data.Text
6−-- Copyright : (c) Tom Harper 2008-2009,
7−-- (c) Bryan O'Sullivan 2009,
12+-- Copyright : (c) 2009, 2010, 2011, 2012 Bryan O'Sullivan,
8−-- (c) Duncan Coutts 2009
13+-- (c) 2009 Duncan Coutts,
14+-- (c) 2008, 2009 Tom Harper
10-- License : BSD-style
16-- License : BSD-style
11−-- Maintainer : bos@serpentine.com, rtharper@aftereternity.co.uk,
17+-- Maintainer : bos@serpentine.com
13-- Stability : experimental
18-- Stability : experimental
14-- Portability : GHC
19-- Portability : GHC
16−-- A time and space-efficient implementation of Unicode text using
21+-- A time and space-efficient implementation of Unicode text.
17−-- packed Word16 arrays. Suitable for performance critical use, both
22+-- Suitable for performance critical use, both in terms of large data
18−-- in terms of large data quantities and high speed.
23+-- quantities and high speed.
25+-- /Note/: Read below the synopsis for important notes on the use of
20-- This module is intended to be imported @qualified@, to avoid name
28-- This module is intended to be imported @qualified@, to avoid name
21-- clashes with "Prelude" functions, e.g.
29-- clashes with "Prelude" functions, e.g.
23-- > import qualified Data.Text as T
31-- > import qualified Data.Text as T
33+-- To use an extended and very rich family of functions for working
34+-- with Unicode text (including normalization, regular expressions,
35+-- non-standard encodings, text breaking, and locales), see
36+-- <http://hackage.haskell.org/package/text-icu the text-icu package >.
25module Data.Text
38module Data.Text
40+ -- * Strict vs lazy types
27 -- * Fusion
46 -- * Fusion
28 -- $fusion
47 -- $fusion
@@ -47,6 +66,7 @@ module Data.Text
51 -- * Transformations
71 -- * Transformations
@@ -61,6 +81,7 @@ module Data.Text
61 , toCaseFold
81 , toCaseFold
65 -- ** Justification
86 -- ** Justification
66 , justifyLeft
87 , justifyLeft
@@ -104,8 +125,11 @@ module Data.Text
105 -- ** Breaking strings
126 -- ** Breaking strings
108 , takeWhile
131 , takeWhile
109 , dropWhile
133 , dropWhile
110 , dropWhileEnd
134 , dropWhileEnd
111 , dropAround
135 , dropAround
@@ -113,10 +137,10 @@ module Data.Text
113 , stripStart
137 , stripStart
114 , stripEnd
138 , stripEnd
115 , splitAt
139 , splitAt
116− , spanBy
140+ , breakOn
118− , breakEnd
143+ , span
121 , groupBy
145 , groupBy
@@ -124,8 +148,8 @@ module Data.Text
125 -- ** Breaking into many substrings
149 -- ** Breaking into many substrings
126 -- $split
150 -- $split
129 , chunksOf
153 , chunksOf
131 -- ** Breaking into lines and words
155 -- ** Breaking into lines and words
@@ -140,130 +164,309 @@ module Data.Text
140 , isSuffixOf
164 , isSuffixOf
141 , isInfixOf
165 , isInfixOf
143 -- * Searching
172 -- * Searching
146− , findBy
176+ , partition
149 -- , findSubstring
178 -- , findSubstring
151 -- * Indexing
180 -- * Indexing
152 -- $index
181 -- $index
154 , findIndex
183 , findIndex
157− -- * Zipping and unzipping
186+ -- * Zipping
159 , zipWith
188 , zipWith
161 -- -* Ordered text
190 -- -* Ordered text
162 -- , sort
191 -- , sort
193+ -- * Low level operations
165−import Prelude (Char, Bool(..), Functor(..), Int, Maybe(..), String,
198+import Prelude (Char, Bool(..), Int, Maybe(..), String,
166− Eq(..), Ord(..), (++),
199+ Eq(..), Ord(..), Ordering(..), (++),
167− Read(..), Show(..),
200+ Read(..),
168− (&&), (||), (+), (-), (.), ($), (>>), (*),
201+ (&&), (||), (+), (-), (.), ($), ($!), (>>),
169− div, not, return, otherwise)
202+ not, return, otherwise, quot)
203+#if defined(HAVE_DEEPSEQ)
170−import Control.DeepSeq (NFData)
204+import Control.DeepSeq (NFData(rnf))
171import Control.Exception (assert)
207import Control.Exception (assert)
172import Data.Char (isSpace)
209import Data.Char (isSpace)
210+import Data.Data (Data(gfoldl, toConstr, gunfold, dataTypeOf), constrIndex,
211+ Constr, mkConstr, DataType, mkDataType, Fixity(Prefix))
173import Control.Monad (foldM)
212import Control.Monad (foldM)
174import Control.Monad.ST (ST)
213import Control.Monad.ST (ST)
175import qualified Data.Text.Array as A
214import qualified Data.Text.Array as A
176import qualified Data.List as L
215import qualified Data.List as L
216+import Data.Binary (Binary(get, put))
177import Data.Monoid (Monoid(..))
217import Data.Monoid (Monoid(..))
218+#if MIN_VERSION_base(4,9,0)
178−import Data.Word (Word16)
219+import Data.Semigroup (Semigroup(..))
179import Data.String (IsString(..))
221import Data.String (IsString(..))
180−import qualified Data.Text.Fusion as S
222+import qualified Data.Text.Internal.Fusion as S
181−import qualified Data.Text.Fusion.Common as S
223+import qualified Data.Text.Internal.Fusion.Common as S
224+import Data.Text.Encoding (decodeUtf8', encodeUtf8)
182−import Data.Text.Fusion (stream, reverseStream, unstream)
225+import Data.Text.Internal.Fusion (stream, reverseStream, unstream)
183−import Data.Text.Internal (Text(..), empty, text, textP)
226+import Data.Text.Internal.Private (span_)
227+import Data.Text.Internal (Text(..), empty, firstf, mul, safe, text)
228+import Data.Text.Show (singleton, unpack, unpackCString#)
184import qualified Prelude as P
229import qualified Prelude as P
185−import Data.Text.Unsafe (iter, iter_, reverseIter, unsafeHead, unsafeTail)
230+import Data.Text.Unsafe (Iter(..), iter, iter_, lengthWord16, reverseIter,
231+ reverseIter_, unsafeHead, unsafeTail)
186−import Data.Text.UnsafeChar (unsafeChr)
232+import Data.Text.Internal.Unsafe.Char (unsafeChr)
187−import qualified Data.Text.Encoding.Utf16 as U16
233+import qualified Data.Text.Internal.Functions as F
234+import qualified Data.Text.Internal.Encoding.Utf16 as U16
188−import Data.Text.Search (indices)
235+import Data.Text.Internal.Search (indices)
236+#if defined(__HADDOCK__)
237+import Data.ByteString (ByteString)
238+import qualified Data.Text.Lazy as L
239+import Data.Int (Int64)
241+import GHC.Base (eqInt, neInt, gtInt, geInt, ltInt, leInt)
242+#if __GLASGOW_HASKELL__ >= 708
243+import qualified GHC.Exts as Exts
245+#if MIN_VERSION_base(4,7,0)
246+import Text.Printf (PrintfArg, formatArg, formatString)
251+-- This package provides both strict and lazy 'Text' types. The
252+-- strict type is provided by the "Data.Text" module, while the lazy
253+-- type is provided by the "Data.Text.Lazy" module. Internally, the
254+-- lazy @Text@ type consists of a list of strict chunks.
256+-- The strict 'Text' type requires that an entire string fit into
257+-- memory at once. The lazy 'Data.Text.Lazy.Text' type is capable of
258+-- streaming strings that are larger than memory using a small memory
259+-- footprint. In many cases, the overhead of chunked streaming makes
260+-- the lazy 'Data.Text.Lazy.Text' type slower than its strict
261+-- counterpart, but this is not always the case. Sometimes, the time
262+-- complexity of a function in one module may be different from the
263+-- other, due to their differing internal structures.
265+-- Each module provides an almost identical API, with the main
266+-- difference being that the strict module uses 'Int' values for
267+-- lengths and counts, while the lazy module uses 'Data.Int.Int64'
272+-- A 'Text' value is a sequence of Unicode scalar values, as defined
274+-- <http://www.unicode.org/versions/Unicode5.2.0/ch03.pdf#page=35 §3.9, definition D76 of the Unicode 5.2 standard >.
275+-- As such, a 'Text' cannot contain values in the range U+D800 to
276+-- U+DFFF inclusive. Haskell implementations admit all Unicode code
278+-- (<http://www.unicode.org/versions/Unicode5.2.0/ch03.pdf#page=13 §3.4, definition D10 >)
279+-- as 'Char' values, including code points from this invalid range.
280+-- This means that there are some 'Char' values that are not valid
281+-- Unicode scalar values, and the functions in this module must handle
284+-- Within this module, many functions construct a 'Text' from one or
285+-- more 'Char' values. Those functions will substitute 'Char' values
286+-- that are not valid Unicode scalar values with the replacement
287+-- character \"�\" (U+FFFD). Functions that perform this
288+-- inspection and replacement are documented with the phrase
289+-- \"Performs replacement on invalid scalar values\".
291+-- (One reason for this policy of replacement is that internally, a
292+-- 'Text' value is represented as packed UTF-16 data. Values in the
293+-- range U+D800 through U+DFFF are used by UTF-16 to denote surrogate
294+-- code points, and so cannot be represented. The functions replace
295+-- invalid scalar values, instead of dropping them, as a security
296+-- measure. For details, see
297+-- <http://unicode.org/reports/tr36/#Deletion_of_Noncharacters Unicode Technical Report 36, §3.5 >.)
190-- $fusion
299-- $fusion
192-- Most of the functions in this module are subject to /fusion/,
301-- Most of the functions in this module are subject to /fusion/,
193-- meaning that a pipeline of such functions will usually allocate at
302-- meaning that a pipeline of such functions will usually allocate at
194-- most one 'Text' value.
303-- most one 'Text' value.
305+-- As an example, consider the following pipeline:
307+-- > import Data.Text as T
308+-- > import Data.Text.Encoding as E
309+-- > import Data.ByteString (ByteString)
311+-- > countChars :: ByteString -> Int
312+-- > countChars = T.length . T.toUpper . E.decodeUtf8
314+-- From the type signatures involved, this looks like it should
315+-- allocate one 'Data.ByteString.ByteString' value, and two 'Text'
316+-- values. However, when a module is compiled with optimisation
317+-- enabled under GHC, the two intermediate 'Text' values will be
318+-- optimised away, and the function will be compiled down to a single
319+-- loop over the source 'Data.ByteString.ByteString'.
321+-- Functions that can be fused by the compiler are documented with the
322+-- phrase \"Subject to fusion\".
196instance Eq Text where
324instance Eq Text where
197− t1 == t2 = stream t1 == stream t2
325+ Text arrA offA lenA == Text arrB offB lenB
326+ | lenA == lenB = A.equal arrA offA arrB offB lenA
198 {-# INLINE (==) #-}
328 {-# INLINE (==) #-}
200instance Ord Text where
330instance Ord Text where
201− compare t1 t2 = compare (stream t1) (stream t2)
331+ compare = compareText
202− {-# INLINE compare #-}
204−instance Show Text where
205− showsPrec p ps r = showsPrec p (unpack ps) r
207instance Read Text where
333instance Read Text where
208 readsPrec p str = [(pack x,y) | (x,y) <- readsPrec p str]
334 readsPrec p str = [(pack x,y) | (x,y) <- readsPrec p str]
336+#if MIN_VERSION_base(4,9,0)
337+-- Semigroup orphan instances for older GHCs are provided by
338+-- 'semigroups` package
340+instance Semigroup Text where
210instance Monoid Text where
344instance Monoid Text where
211 mempty = empty
345 mempty = empty
346+#if MIN_VERSION_base(4,9,0)
347+ mappend = (<>) -- future-proof definition
212 mappend = append
349 mappend = append
213 mconcat = concat
351 mconcat = concat
215instance IsString Text where
353instance IsString Text where
216 fromString = pack
354 fromString = pack
356+#if __GLASGOW_HASKELL__ >= 708
357+instance Exts.IsList Text where
358+ type Item Text = Char
363+#if defined(HAVE_DEEPSEQ)
218−instance NFData Text
364+instance NFData Text where rnf !_ = ()
367+instance Binary Text where
368+ put t = put (encodeUtf8 t)
371+ case decodeUtf8' bs of
372+ P.Left exn -> P.fail (P.show exn)
373+ P.Right a -> P.return a
375+-- | This instance preserves data abstraction at the cost of inefficiency.
376+-- We omit reflection services for the sake of data abstraction.
378+-- This instance was created by copying the updated behavior of
379+-- @"Data.Set".@'Data.Set.Set' and @"Data.Map".@'Data.Map.Map'. If you
380+-- feel a mistake has been made, please feel free to submit
383+-- The original discussion is archived here:
384+-- <http://groups.google.com/group/haskell-cafe/browse_thread/thread/b5bbb1b28a7e525d/0639d46852575b93 could we get a Data instance for Data.Text.Text? >
386+-- The followup discussion that changed the behavior of 'Data.Set.Set'
387+-- and 'Data.Map.Map' is archived here:
388+-- <http://markmail.org/message/trovdc6zkphyi3cr#query:+page:1+mid:a46der3iacwjcf6n+state:results Proposal: Allow gunfold for Data.Map, ... >
390+instance Data Text where
391+ gfoldl f z txt = z pack `f` (unpack txt)
392+ toConstr _ = packConstr
393+ gunfold k z c = case constrIndex c of
395+ _ -> P.error "gunfold"
396+ dataTypeOf _ = textDataType
398+#if MIN_VERSION_base(4,7,0)
399+-- | Only defined for @base-4.7.0.0@ and later
400+instance PrintfArg Text where
401+ formatArg txt = formatString $ unpack txt
405+packConstr = mkConstr textDataType "pack" [] Prefix
407+textDataType :: DataType
408+textDataType = mkDataType "Data.Text.Text" [packConstr]
410+-- | /O(n)/ Compare two 'Text' values lexicographically.
411+compareText :: Text -> Text -> Ordering
412+compareText ta@(Text _arrA _offA lenA) tb@(Text _arrB _offB lenB)
413+ | lenA == 0 && lenB == 0 = EQ
414+ | otherwise = go 0 0
417+ | i >= lenA || j >= lenB = compare lenA lenB
420+ | otherwise = go (i+di) (j+dj)
421+ where Iter a di = iter ta i
422+ Iter b dj = iter tb j
220-- -----------------------------------------------------------------------------
424-- -----------------------------------------------------------------------------
221-- * Conversion to/from 'Text'
425-- * Conversion to/from 'Text'
223−-- | /O(n)/ Convert a 'String' into a 'Text'. Subject to fusion.
427+-- | /O(n)/ Convert a 'String' into a 'Text'. Subject to
428+-- fusion. Performs replacement on invalid scalar values.
224pack :: String -> Text
429pack :: String -> Text
225−pack = unstream . S.streamList
430+pack = unstream . S.map safe . S.streamList
226{-# INLINE [1] pack #-}
431{-# INLINE [1] pack #-}
228−-- | /O(n)/ Convert a Text into a String. Subject to fusion.
229−unpack :: Text -> String
230−unpack = S.unstreamList . stream
231−{-# INLINE [1] unpack #-}
233−-- | /O(1)/ Convert a character into a Text.
234−-- Subject to fusion.
235−singleton :: Char -> Text
236−singleton = unstream . S.singleton
237−{-# INLINE [1] singleton #-}
239-- -----------------------------------------------------------------------------
433-- -----------------------------------------------------------------------------
240-- * Basic functions
434-- * Basic functions
242-- | /O(n)/ Adds a character to the front of a 'Text'. This function
436-- | /O(n)/ Adds a character to the front of a 'Text'. This function
243-- is more costly than its 'List' counterpart because it requires
437-- is more costly than its 'List' counterpart because it requires
244−-- copying a new array. Subject to fusion.
438+-- copying a new array. Subject to fusion. Performs replacement on
439+-- invalid scalar values.
245cons :: Char -> Text -> Text
440cons :: Char -> Text -> Text
246−cons c t = unstream (S.cons c (stream t))
441+cons c t = unstream (S.cons (safe c) (stream t))
247{-# INLINE cons #-}
442{-# INLINE cons #-}
249-- | /O(n)/ Adds a character to the end of a 'Text'. This copies the
446-- | /O(n)/ Adds a character to the end of a 'Text'. This copies the
250-- entire array in the process, unless fused. Subject to fusion.
447-- entire array in the process, unless fused. Subject to fusion.
448+-- Performs replacement on invalid scalar values.
251snoc :: Text -> Char -> Text
449snoc :: Text -> Char -> Text
252−snoc t c = unstream (S.snoc (stream t) c)
450+snoc t c = unstream (S.snoc (stream t) (safe c))
253{-# INLINE snoc #-}
451{-# INLINE snoc #-}
255-- | /O(n)/ Appends one 'Text' to the other by copying both of them
453-- | /O(n)/ Appends one 'Text' to the other by copying both of them
256-- into a new 'Text'. Subject to fusion.
454-- into a new 'Text'. Subject to fusion.
257append :: Text -> Text -> Text
455append :: Text -> Text -> Text
258−append (Text arr1 off1 len1) (Text arr2 off2 len2) = Text (A.run x) 0 len
456+append a@(Text arr1 off1 len1) b@(Text arr2 off2 len2)
459+ | len > 0 = Text (A.run x) 0 len
460+ | otherwise = overflowError "append"
260 len = len1+len2
462 len = len1+len2
463+ x :: ST s (A.MArray s)
262− arr <- A.unsafeNew len
465+ arr <- A.new len
263− copy arr 0 arr1 off1 len1
466+ A.copyI arr 0 arr1 off1 len1
264− copy arr len1 arr2 off2 (len1+len2)
467+ A.copyI arr len1 arr2 off2 len
265 return arr
468 return arr
266−{-# INLINE append #-}
469+{-# NOINLINE append #-}
269"TEXT append -> fused" [~1] forall t1 t2.
472"TEXT append -> fused" [~1] forall t1 t2.
@@ -272,14 +475,6 @@ append (Text arr1 off1 len1) (Text arr2 off2 len2) = Text (A.run x) 0 len
272 unstream (S.append (stream t1) (stream t2)) = append t1 t2
475 unstream (S.append (stream t1) (stream t2)) = append t1 t2
275−copy :: forall s. A.MArray s Word16 -> Int -> A.Array Word16 -> Int -> Int
277−copy dest i0 src j0 top = go i0 j0
279− go i j | i >= top = return ()
280− | otherwise = do A.unsafeWrite dest i (src `A.unsafeIndex` j)
283-- | /O(1)/ Returns the first character of a 'Text', which must be
478-- | /O(1)/ Returns the first character of a 'Text', which must be
284-- non-empty. Subject to fusion.
479-- non-empty. Subject to fusion.
285head :: Text -> Char
480head :: Text -> Char
@@ -291,21 +486,14 @@ head t = S.head (stream t)
291uncons :: Text -> Maybe (Char, Text)
486uncons :: Text -> Maybe (Char, Text)
292uncons t@(Text arr off len)
487uncons t@(Text arr off len)
293 | len <= 0 = Nothing
488 | len <= 0 = Nothing
489+ | otherwise = Just $ let !(Iter c d) = iter t 0
294− | otherwise = Just (c, textP arr (off+d) (len-d))
490+ in (c, text arr (off+d) (len-d))
295− where (c,d) = iter t 0
296{-# INLINE [1] uncons #-}
491{-# INLINE [1] uncons #-}
298-- | Lifted from Control.Arrow and specialized.
493-- | Lifted from Control.Arrow and specialized.
299second :: (b -> c) -> (a,b) -> (a,c)
494second :: (b -> c) -> (a,b) -> (a,c)
300second f (a, b) = (a, f b)
495second f (a, b) = (a, f b)
303−"TEXT uncons -> fused" [~1] forall t.
304− uncons t = fmap (second unstream) (S.uncons (stream t))
305−"TEXT uncons -> unfused" [1] forall t.
306− fmap (second unstream) (S.uncons (stream t)) = uncons t
309-- | /O(1)/ Returns the last character of a 'Text', which must be
497-- | /O(1)/ Returns the last character of a 'Text', which must be
310-- non-empty. Subject to fusion.
498-- non-empty. Subject to fusion.
311last :: Text -> Char
499last :: Text -> Char
@@ -329,7 +517,7 @@ last (Text arr off len)
329tail :: Text -> Text
517tail :: Text -> Text
330tail t@(Text arr off len)
518tail t@(Text arr off len)
331 | len <= 0 = emptyError "tail"
519 | len <= 0 = emptyError "tail"
332− | otherwise = textP arr (off+d) (len-d)
520+ | otherwise = text arr (off+d) (len-d)
333 where d = iter_ t 0
521 where d = iter_ t 0
334{-# INLINE [1] tail #-}
522{-# INLINE [1] tail #-}
@@ -344,8 +532,8 @@ tail t@(Text arr off len)
344-- be non-empty. Subject to fusion.
532-- be non-empty. Subject to fusion.
345init :: Text -> Text
533init :: Text -> Text
346init (Text arr off len) | len <= 0 = emptyError "init"
534init (Text arr off len) | len <= 0 = emptyError "init"
347− | n >= 0xDC00 && n <= 0xDFFF = textP arr off (len-2)
535+ | n >= 0xDC00 && n <= 0xDFFF = text arr off (len-2)
348− | otherwise = textP arr off (len-1)
536+ | otherwise = text arr off (len-1)
350 n = A.unsafeIndex arr (off+len-1)
538 n = A.unsafeIndex arr (off+len-1)
351{-# INLINE [1] init #-}
539{-# INLINE [1] init #-}
@@ -360,7 +548,11 @@ init (Text arr off len) | len <= 0 = emptyError "init"
360-- | /O(1)/ Tests whether a 'Text' is empty or not. Subject to
548-- | /O(1)/ Tests whether a 'Text' is empty or not. Subject to
361-- fusion.
549-- fusion.
362null :: Text -> Bool
550null :: Text -> Bool
363−null (Text _arr _off len) = assert (len >= 0) $ len <= 0
551+null (Text _arr _off len) =
364{-# INLINE [1] null #-}
556{-# INLINE [1] null #-}
@@ -380,27 +572,76 @@ isSingleton = S.isSingleton . stream
380-- Subject to fusion.
572-- Subject to fusion.
381length :: Text -> Int
573length :: Text -> Int
382length t = S.length (stream t)
574length t = S.length (stream t)
383−{-# INLINE length #-}
575+{-# INLINE [0] length #-}
576+-- length needs to be phased after the compareN/length rules otherwise
577+-- it may inline before the rules have an opportunity to fire.
579+-- | /O(n)/ Compare the count of characters in a 'Text' to a number.
580+-- Subject to fusion.
582+-- This function gives the same answer as comparing against the result
583+-- of 'length', but can short circuit if the count of characters is
584+-- greater than the number, and hence be more efficient.
585+compareLength :: Text -> Int -> Ordering
586+compareLength t n = S.compareLengthI (stream t) n
587+{-# INLINE [1] compareLength #-}
590+"TEXT compareN/length -> compareLength" [~1] forall t n.
591+ compare (length t) n = compareLength t n
595+"TEXT ==N/length -> compareLength/==EQ" [~1] forall t n.
596+ eqInt (length t) n = compareLength t n == EQ
600+"TEXT /=N/length -> compareLength//=EQ" [~1] forall t n.
601+ neInt (length t) n = compareLength t n /= EQ
605+"TEXT <N/length -> compareLength/==LT" [~1] forall t n.
606+ ltInt (length t) n = compareLength t n == LT
610+"TEXT <=N/length -> compareLength//=GT" [~1] forall t n.
611+ leInt (length t) n = compareLength t n /= GT
615+"TEXT >N/length -> compareLength/==GT" [~1] forall t n.
616+ gtInt (length t) n = compareLength t n == GT
620+"TEXT >=N/length -> compareLength//=LT" [~1] forall t n.
621+ geInt (length t) n = compareLength t n /= LT
385-- -----------------------------------------------------------------------------
624-- -----------------------------------------------------------------------------
386-- * Transformations
625-- * Transformations
387-- | /O(n)/ 'map' @f@ @t@ is the 'Text' obtained by applying @f@ to
626-- | /O(n)/ 'map' @f@ @t@ is the 'Text' obtained by applying @f@ to
388−-- each element of @t@. Subject to fusion.
627+-- each element of @t@. Subject to fusion. Performs replacement on
628+-- invalid scalar values.
389map :: (Char -> Char) -> Text -> Text
629map :: (Char -> Char) -> Text -> Text
390−map f t = unstream (S.map f (stream t))
630+map f t = unstream (S.map (safe . f) (stream t))
391{-# INLINE [1] map #-}
631{-# INLINE [1] map #-}
393-- | /O(n)/ The 'intercalate' function takes a 'Text' and a list of
633-- | /O(n)/ The 'intercalate' function takes a 'Text' and a list of
394-- 'Text's and concatenates the list after interspersing the first
634-- 'Text's and concatenates the list after interspersing the first
395-- argument between each element of the list.
635-- argument between each element of the list.
396intercalate :: Text -> [Text] -> Text
636intercalate :: Text -> [Text] -> Text
397−intercalate t = concat . (L.intersperse t)
637+intercalate t = concat . (F.intersperse t)
398{-# INLINE intercalate #-}
638{-# INLINE intercalate #-}
400-- | /O(n)/ The 'intersperse' function takes a character and places it
640-- | /O(n)/ The 'intersperse' function takes a character and places it
401−-- between the characters of a 'Text'. Subject to fusion.
641+-- between the characters of a 'Text'. Subject to fusion. Performs
642+-- replacement on invalid scalar values.
402intersperse :: Char -> Text -> Text
643intersperse :: Char -> Text -> Text
403−intersperse c t = unstream (S.intersperse c (stream t))
644+intersperse c t = unstream (S.intersperse (safe c) (stream t))
404{-# INLINE intersperse #-}
645{-# INLINE intersperse #-}
406-- | /O(n)/ Reverse the characters of a string. Subject to fusion.
647-- | /O(n)/ Reverse the characters of a string. Subject to fusion.
@@ -408,13 +649,59 @@ reverse :: Text -> Text
408reverse t = S.reverse (stream t)
649reverse t = S.reverse (stream t)
409{-# INLINE reverse #-}
650{-# INLINE reverse #-}
411−-- | /O(m+n)/ Replace every occurrence of one substring with another.
652+-- | /O(m+n)/ Replace every non-overlapping occurrence of @needle@ in
653+-- @haystack@ with @replacement@.
655+-- This function behaves as though it was defined as follows:
658+-- replace needle replacement haystack =
659+-- 'intercalate' replacement ('splitOn' needle haystack)
662+-- As this suggests, each occurrence is replaced exactly once. So if
663+-- @needle@ occurs in @replacement@, that occurrence will /not/ itself
664+-- be replaced recursively:
666+-- > replace "oo" "foo" "oo" == "foo"
668+-- In cases where several instances of @needle@ overlap, only the
669+-- first one will be replaced:
671+-- > replace "ofo" "bar" "ofofo" == "barfo"
673+-- In (unlikely) bad cases, this function's time complexity degrades
412−replace :: Text -- ^ Text to search for
675+replace :: Text
413− -> Text -- ^ Replacement text
676+ -- ^ @needle@ to search for. If this string is empty, an
414− -> Text -- ^ Input text
677+ -- error will occur.
416−replace s d = intercalate d . split s
679+ -- ^ @replacement@ to replace @needle@ with.
417−{-# INLINE replace #-}
680+ -> Text
681+ -- ^ @haystack@ in which to search.
683+replace needle@(Text _ _ neeLen)
684+ (Text repArr repOff repLen)
685+ haystack@(Text hayArr hayOff hayLen)
686+ | neeLen == 0 = emptyError "replace"
687+ | L.null ixs = haystack
688+ | len > 0 = Text (A.run x) 0 len
691+ ixs = indices needle haystack
692+ len = hayLen - (neeLen - repLen) `mul` L.length ixs
693+ x :: ST s (A.MArray s)
696+ let loop (i:is) o d = do
699+ A.copyI marr d hayArr (hayOff+o) d0
700+ A.copyI marr d0 repArr repOff d1
701+ loop is (i + neeLen) d1
702+ loop [] o d = A.copyI marr d hayArr (hayOff+o) len
419-- ----------------------------------------------------------------------------
706-- ----------------------------------------------------------------------------
420-- ** Case conversions (folds)
707-- ** Case conversions (folds)
@@ -429,10 +716,17 @@ replace s d = intercalate d . split s
429-- case conversion rules. As a result, these functions may map one
716-- case conversion rules. As a result, these functions may map one
430-- input character to two or three output characters. For examples,
717-- input character to two or three output characters. For examples,
431-- see the documentation of each function.
718-- see the documentation of each function.
720+-- /Note/: In some languages, case conversion is a locale- and
721+-- context-dependent operation. The case conversion functions in this
722+-- module are /not/ locale sensitive. Programs that require locale
723+-- sensitivity should use appropriate versions of the
724+-- <http://hackage.haskell.org/package/text-icu-0.6.3.7/docs/Data-Text-ICU.html#g:4 case mapping functions from the text-icu package >.
433−-- | /O(n)/ Convert a string to folded case. This function is mainly
726+-- | /O(n)/ Convert a string to folded case. Subject to fusion.
434−-- useful for performing caseless (also known as case insensitive)
728+-- This function is mainly useful for performing caseless (also known
435−-- string comparisons.
729+-- as case insensitive) string comparisons.
437-- A string @x@ is a caseless match for a string @y@ if and only if:
731-- A string @x@ is a caseless match for a string @y@ if and only if:
@@ -447,27 +741,56 @@ replace s d = intercalate d . split s
447-- instead of itself.
741-- instead of itself.
448toCaseFold :: Text -> Text
742toCaseFold :: Text -> Text
449toCaseFold t = unstream (S.toCaseFold (stream t))
743toCaseFold t = unstream (S.toCaseFold (stream t))
450−{-# INLINE [0] toCaseFold #-}
744+{-# INLINE toCaseFold #-}
452-- | /O(n)/ Convert a string to lower case, using simple case
746-- | /O(n)/ Convert a string to lower case, using simple case
747+-- conversion. Subject to fusion.
453−-- conversion. The result string may be longer than the input string.
749+-- The result string may be longer than the input string. For
454−-- For instance, \"İ\" (Latin capital letter I with dot above,
750+-- instance, \"İ\" (Latin capital letter I with dot above,
455−-- U+0130) maps to the sequence \"i\" (Latin small letter i, U+0069) followed
751+-- U+0130) maps to the sequence \"i\" (Latin small letter i, U+0069)
456−-- by \" ̇\" (combining dot above, U+0307).
752+-- followed by \" ̇\" (combining dot above, U+0307).
457toLower :: Text -> Text
753toLower :: Text -> Text
458toLower t = unstream (S.toLower (stream t))
754toLower t = unstream (S.toLower (stream t))
459{-# INLINE toLower #-}
755{-# INLINE toLower #-}
461-- | /O(n)/ Convert a string to upper case, using simple case
757-- | /O(n)/ Convert a string to upper case, using simple case
758+-- conversion. Subject to fusion.
462−-- conversion. The result string may be longer than the input string.
760+-- The result string may be longer than the input string. For
463−-- For instance, the German \"ß\" (eszett, U+00DF) maps to the
761+-- instance, the German \"ß\" (eszett, U+00DF) maps to the
464-- two-letter sequence \"SS\".
762-- two-letter sequence \"SS\".
465toUpper :: Text -> Text
763toUpper :: Text -> Text
466toUpper t = unstream (S.toUpper (stream t))
764toUpper t = unstream (S.toUpper (stream t))
467{-# INLINE toUpper #-}
765{-# INLINE toUpper #-}
767+-- | /O(n)/ Convert a string to title case, using simple case
768+-- conversion. Subject to fusion.
770+-- The first letter of the input is converted to title case, as is
771+-- every subsequent letter that immediately follows a non-letter.
772+-- Every letter that immediately follows another letter is converted
775+-- The result string may be longer than the input string. For example,
776+-- the Latin small ligature fl (U+FB02) is converted to the
777+-- sequence Latin capital letter F (U+0046) followed by Latin small
778+-- letter l (U+006C).
780+-- /Note/: this function does not take language or culture specific
781+-- rules into account. For instance, in English, different style
782+-- guides disagree on whether the book name \"The Hill of the Red
783+-- Fox\" is correctly title cased—but this function will
784+-- capitalize /every/ word.
785+toTitle :: Text -> Text
786+toTitle t = unstream (S.toTitle (stream t))
787+{-# INLINE toTitle #-}
469-- | /O(n)/ Left-justify a string to the given length, using the
789-- | /O(n)/ Left-justify a string to the given length, using the
470−-- specified fill character on the right. Subject to fusion. Examples:
790+-- specified fill character on the right. Subject to fusion.
791+-- Performs replacement on invalid scalar values.
472-- > justifyLeft 7 'x' "foo" == "fooxxxx"
795-- > justifyLeft 7 'x' "foo" == "fooxxxx"
473-- > justifyLeft 3 'x' "foobar" == "foobar"
796-- > justifyLeft 3 'x' "foobar" == "foobar"
@@ -486,7 +809,10 @@ justifyLeft k c t
488-- | /O(n)/ Right-justify a string to the given length, using the
811-- | /O(n)/ Right-justify a string to the given length, using the
489−-- specified fill character on the left. Examples:
812+-- specified fill character on the left. Performs replacement on
813+-- invalid scalar values.
491-- > justifyRight 7 'x' "bar" == "xxxxbar"
817-- > justifyRight 7 'x' "bar" == "xxxxbar"
492-- > justifyRight 3 'x' "foobar" == "foobar"
818-- > justifyRight 3 'x' "foobar" == "foobar"
@@ -497,8 +823,11 @@ justifyRight k c t
497 where len = length t
823 where len = length t
498{-# INLINE justifyRight #-}
824{-# INLINE justifyRight #-}
500−-- | /O(n)/ Center a string to the given length, using the
826+-- | /O(n)/ Center a string to the given length, using the specified
501−-- specified fill character on either side. Examples:
827+-- fill character on either side. Performs replacement on invalid
503-- > center 8 'x' "HS" = "xxxHSxxx"
832-- > center 8 'x' "HS" = "xxxHSxxx"
504center :: Int -> Char -> Text -> Text
833center :: Int -> Char -> Text -> Text
@@ -507,7 +836,7 @@ center k c t
507 | otherwise = replicateChar l c `append` t `append` replicateChar r c
836 | otherwise = replicateChar l c `append` t `append` replicateChar r c
508 where len = length t
837 where len = length t
509 d = k - len
838 d = k - len
510− r = d `div` 2
839+ r = d `quot` 2
511 l = d - r
840 l = d - r
512{-# INLINE center #-}
841{-# INLINE center #-}
@@ -525,12 +854,12 @@ transpose ts = P.map pack (L.transpose (P.map unpack ts))
525-- (typically the left-identity of the operator), and a 'Text',
854-- (typically the left-identity of the operator), and a 'Text',
526-- reduces the 'Text' using the binary operator, from left to right.
855-- reduces the 'Text' using the binary operator, from left to right.
527-- Subject to fusion.
856-- Subject to fusion.
528−foldl :: (b -> Char -> b) -> b -> Text -> b
857+foldl :: (a -> Char -> a) -> a -> Text -> a
529foldl f z t = S.foldl f z (stream t)
858foldl f z t = S.foldl f z (stream t)
530{-# INLINE foldl #-}
859{-# INLINE foldl #-}
532-- | /O(n)/ A strict version of 'foldl'. Subject to fusion.
861-- | /O(n)/ A strict version of 'foldl'. Subject to fusion.
533−foldl' :: (b -> Char -> b) -> b -> Text -> b
862+foldl' :: (a -> Char -> a) -> a -> Text -> a
534foldl' f z t = S.foldl' f z (stream t)
863foldl' f z t = S.foldl' f z (stream t)
535{-# INLINE foldl' #-}
864{-# INLINE foldl' #-}
@@ -549,12 +878,12 @@ foldl1' f t = S.foldl1' f (stream t)
549-- (typically the right-identity of the operator), and a 'Text',
878-- (typically the right-identity of the operator), and a 'Text',
550-- reduces the 'Text' using the binary operator, from right to left.
879-- reduces the 'Text' using the binary operator, from right to left.
551-- Subject to fusion.
880-- Subject to fusion.
552−foldr :: (Char -> b -> b) -> b -> Text -> b
881+foldr :: (Char -> a -> a) -> a -> Text -> a
553foldr f z t = S.foldr f z (stream t)
882foldr f z t = S.foldr f z (stream t)
554{-# INLINE foldr #-}
883{-# INLINE foldr #-}
556-- | /O(n)/ A variant of 'foldr' that has no starting value argument,
885-- | /O(n)/ A variant of 'foldr' that has no starting value argument,
557−-- and thust must be applied to a non-empty 'Text'. Subject to
886+-- and thus must be applied to a non-empty 'Text'. Subject to
558-- fusion.
887-- fusion.
559foldr1 :: (Char -> Char -> Char) -> Text -> Char
888foldr1 :: (Char -> Char -> Char) -> Text -> Char
560foldr1 f t = S.foldr1 f (stream t)
889foldr1 f t = S.foldr1 f (stream t)
@@ -565,14 +894,19 @@ foldr1 f t = S.foldr1 f (stream t)
566-- | /O(n)/ Concatenate a list of 'Text's.
895-- | /O(n)/ Concatenate a list of 'Text's.
567concat :: [Text] -> Text
896concat :: [Text] -> Text
897+concat ts = case ts' of
568−concat ts = Text (A.run go) 0 len
900+ _ -> Text (A.run go) 0 len
570− len = L.sum (L.map (\(Text _ _ l) -> l) ts)
902+ ts' = L.filter (not . null) ts
903+ len = sumP "concat" $ L.map lengthWord16 ts'
904+ go :: ST s (A.MArray s)
572− arr <- A.unsafeNew len
906+ arr <- A.new len
907+ let step i (Text a o l) =
573− let step i (Text a o l) = let j = i + l in copy arr i a o j >> return j
908+ let !j = i + l in A.copyI arr i a o j >> return j
574− foldM step 0 ts >> return arr
909+ foldM step 0 ts' >> return arr
575−{-# INLINE concat #-}
577-- | /O(n)/ Map a function over a 'Text' that results in a 'Text', and
911-- | /O(n)/ Map a function over a 'Text' that results in a 'Text', and
578-- concatenate the results.
912-- concatenate the results.
@@ -581,13 +915,13 @@ concatMap f = concat . foldr ((:) . f) []
581{-# INLINE concatMap #-}
915{-# INLINE concatMap #-}
583-- | /O(n)/ 'any' @p@ @t@ determines whether any character in the
917-- | /O(n)/ 'any' @p@ @t@ determines whether any character in the
584−-- 'Text' @t@ satisifes the predicate @p@. Subject to fusion.
918+-- 'Text' @t@ satisfies the predicate @p@. Subject to fusion.
585any :: (Char -> Bool) -> Text -> Bool
919any :: (Char -> Bool) -> Text -> Bool
586any p t = S.any p (stream t)
920any p t = S.any p (stream t)
587{-# INLINE any #-}
921{-# INLINE any #-}
589-- | /O(n)/ 'all' @p@ @t@ determines whether all characters in the
923-- | /O(n)/ 'all' @p@ @t@ determines whether all characters in the
590−-- 'Text' @t@ satisify the predicate @p@. Subject to fusion.
924+-- 'Text' @t@ satisfy the predicate @p@. Subject to fusion.
591all :: (Char -> Bool) -> Text -> Bool
925all :: (Char -> Bool) -> Text -> Bool
592all p t = S.all p (stream t)
926all p t = S.all p (stream t)
593{-# INLINE all #-}
927{-# INLINE all #-}
@@ -609,6 +943,7 @@ minimum t = S.minimum (stream t)
610-- | /O(n)/ 'scanl' is similar to 'foldl', but returns a list of
944-- | /O(n)/ 'scanl' is similar to 'foldl', but returns a list of
611-- successive reduced values from the left. Subject to fusion.
945-- successive reduced values from the left. Subject to fusion.
946+-- Performs replacement on invalid scalar values.
613-- > scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
948-- > scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
@@ -616,11 +951,13 @@ minimum t = S.minimum (stream t)
617-- > last (scanl f z xs) == foldl f z xs.
952-- > last (scanl f z xs) == foldl f z xs.
618scanl :: (Char -> Char -> Char) -> Char -> Text -> Text
953scanl :: (Char -> Char -> Char) -> Char -> Text -> Text
619−scanl f z t = unstream (S.scanl f z (stream t))
954+scanl f z t = unstream (S.scanl g z (stream t))
955+ where g a b = safe (f a b)
620{-# INLINE scanl #-}
956{-# INLINE scanl #-}
622-- | /O(n)/ 'scanl1' is a variant of 'scanl' that has no starting
958-- | /O(n)/ 'scanl1' is a variant of 'scanl' that has no starting
623−-- value argument. Subject to fusion.
959+-- value argument. Subject to fusion. Performs replacement on
960+-- invalid scalar values.
625-- > scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
962-- > scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
626scanl1 :: (Char -> Char -> Char) -> Text -> Text
963scanl1 :: (Char -> Char -> Char) -> Text -> Text
@@ -628,40 +965,42 @@ scanl1 f t | null t = empty
628 | otherwise = scanl f (unsafeHead t) (unsafeTail t)
965 | otherwise = scanl f (unsafeHead t) (unsafeTail t)
629{-# INLINE scanl1 #-}
966{-# INLINE scanl1 #-}
631−-- | /O(n)/ 'scanr' is the right-to-left dual of 'scanl'.
968+-- | /O(n)/ 'scanr' is the right-to-left dual of 'scanl'. Performs
969+-- replacement on invalid scalar values.
633-- > scanr f v == reverse . scanl (flip f) v . reverse
971-- > scanr f v == reverse . scanl (flip f) v . reverse
634scanr :: (Char -> Char -> Char) -> Char -> Text -> Text
972scanr :: (Char -> Char -> Char) -> Char -> Text -> Text
635−scanr f z = S.reverse . S.reverseScanr f z . reverseStream
973+scanr f z = S.reverse . S.reverseScanr g z . reverseStream
974+ where g a b = safe (f a b)
636{-# INLINE scanr #-}
975{-# INLINE scanr #-}
638-- | /O(n)/ 'scanr1' is a variant of 'scanr' that has no starting
977-- | /O(n)/ 'scanr1' is a variant of 'scanr' that has no starting
639−-- value argument. Subject to fusion.
978+-- value argument. Subject to fusion. Performs replacement on
979+-- invalid scalar values.
640scanr1 :: (Char -> Char -> Char) -> Text -> Text
980scanr1 :: (Char -> Char -> Char) -> Text -> Text
641scanr1 f t | null t = empty
981scanr1 f t | null t = empty
642 | otherwise = scanr f (last t) (init t)
982 | otherwise = scanr f (last t) (init t)
643{-# INLINE scanr1 #-}
983{-# INLINE scanr1 #-}
645−-- | /O(n)/ Like a combination of 'map' and 'foldl'. Applies a
985+-- | /O(n)/ Like a combination of 'map' and 'foldl''. Applies a
646-- function to each element of a 'Text', passing an accumulating
986-- function to each element of a 'Text', passing an accumulating
647−-- parameter from left to right, and returns a final 'Text'.
987+-- parameter from left to right, and returns a final 'Text'. Performs
988+-- replacement on invalid scalar values.
648mapAccumL :: (a -> Char -> (a,Char)) -> a -> Text -> (a, Text)
989mapAccumL :: (a -> Char -> (a,Char)) -> a -> Text -> (a, Text)
649−mapAccumL f s t = case uncons t of
990+mapAccumL f z0 = S.mapAccumL g z0 . stream
650− Nothing -> (s, empty)
991+ where g a b = second safe (f a b)
651− Just (x, xs) -> (s'', cons y ys)
652− where (s', y ) = f s x
653− (s'',ys) = mapAccumL f s' xs
992+{-# INLINE mapAccumL #-}
655-- | The 'mapAccumR' function behaves like a combination of 'map' and
994-- | The 'mapAccumR' function behaves like a combination of 'map' and
656−-- 'foldr'; it applies a function to each element of a 'Text', passing
995+-- a strict 'foldr'; it applies a function to each element of a
657−-- an accumulating parameter from right to left, and returning a final
996+-- 'Text', passing an accumulating parameter from right to left, and
658−-- value of this accumulator together with the new 'Text'.
997+-- returning a final value of this accumulator together with the new
999+-- Performs replacement on invalid scalar values.
659mapAccumR :: (a -> Char -> (a,Char)) -> a -> Text -> (a, Text)
1000mapAccumR :: (a -> Char -> (a,Char)) -> a -> Text -> (a, Text)
660−mapAccumR f s t = case uncons t of
1001+mapAccumR f z0 = second reverse . S.mapAccumL g z0 . reverseStream
661− Nothing -> (s, empty)
1002+ where g a b = second safe (f a b)
662− Just (x, xs) -> (s'', cons y ys)
663− where (s'',y ) = f s' x
664− (s', ys) = mapAccumR f s xs
1003+{-# INLINE mapAccumR #-}
666-- -----------------------------------------------------------------------------
1005-- -----------------------------------------------------------------------------
667-- ** Generating and unfolding 'Text's
1006-- ** Generating and unfolding 'Text's
@@ -670,17 +1009,18 @@ mapAccumR f s t = case uncons t of
670-- @t@ repeated @n@ times.
1009-- @t@ repeated @n@ times.
671replicate :: Int -> Text -> Text
1010replicate :: Int -> Text -> Text
672replicate n t@(Text a o l)
1011replicate n t@(Text a o l)
673− | n <= 0 || l <= 0 = empty
1012+ | n <= 0 || l <= 0 = empty
674− | n == 1 = t
1013+ | n == 1 = t
675− | isSingleton t = replicateChar n (unsafeHead t)
1014+ | isSingleton t = replicateChar n (unsafeHead t)
676− | otherwise = Text (A.run x) 0 len
1015+ | otherwise = Text (A.run x) 0 len
678− len = l * n
1017+ len = l `mul` n
1018+ x :: ST s (A.MArray s)
680− arr <- A.unsafeNew len
1020+ arr <- A.new len
681 let loop !d !i | i >= n = return arr
1021 let loop !d !i | i >= n = return arr
682 | otherwise = let m = d + l
1022 | otherwise = let m = d + l
683− in copy arr d a o m >> loop m (i+1)
1023+ in A.copyI arr d a o m >> loop m (i+1)
684 loop 0 0
1024 loop 0 0
685{-# INLINE [1] replicate #-}
1025{-# INLINE [1] replicate #-}
@@ -692,7 +1032,7 @@ replicate n t@(Text a o l)
692-- | /O(n)/ 'replicateChar' @n@ @c@ is a 'Text' of length @n@ with @c@ the
1032-- | /O(n)/ 'replicateChar' @n@ @c@ is a 'Text' of length @n@ with @c@ the
693-- value of every element. Subject to fusion.
1033-- value of every element. Subject to fusion.
694replicateChar :: Int -> Char -> Text
1034replicateChar :: Int -> Char -> Text
695−replicateChar n c = unstream (S.replicateCharI n c)
1035+replicateChar n c = unstream (S.replicateCharI n (safe c))
696{-# INLINE replicateChar #-}
1036{-# INLINE replicateChar #-}
698-- | /O(n)/, where @n@ is the length of the result. The 'unfoldr'
1038-- | /O(n)/, where @n@ is the length of the result. The 'unfoldr'
@@ -701,9 +1041,9 @@ replicateChar n c = unstream (S.replicateCharI n c)
701-- returns 'Nothing' if it is done producing the 'Text', otherwise
1041-- returns 'Nothing' if it is done producing the 'Text', otherwise
702-- 'Just' @(a,b)@. In this case, @a@ is the next 'Char' in the
1042-- 'Just' @(a,b)@. In this case, @a@ is the next 'Char' in the
703-- string, and @b@ is the seed value for further production. Subject
1043-- string, and @b@ is the seed value for further production. Subject
704−-- to fusion.
1044+-- to fusion. Performs replacement on invalid scalar values.
705unfoldr :: (a -> Maybe (Char,a)) -> a -> Text
1045unfoldr :: (a -> Maybe (Char,a)) -> a -> Text
706−unfoldr f s = unstream (S.unfoldr f s)
1046+unfoldr f s = unstream (S.unfoldr (firstf safe . f) s)
707{-# INLINE unfoldr #-}
1047{-# INLINE unfoldr #-}
709-- | /O(n)/ Like 'unfoldr', 'unfoldrN' builds a 'Text' from a seed
1049-- | /O(n)/ Like 'unfoldr', 'unfoldrN' builds a 'Text' from a seed
@@ -711,9 +1051,9 @@ unfoldr f s = unstream (S.unfoldr f s)
711-- first argument to 'unfoldrN'. This function is more efficient than
1051-- first argument to 'unfoldrN'. This function is more efficient than
712-- 'unfoldr' when the maximum length of the result is known and
1052-- 'unfoldr' when the maximum length of the result is known and
713-- correct, otherwise its performance is similar to 'unfoldr'. Subject
1053-- correct, otherwise its performance is similar to 'unfoldr'. Subject
714−-- to fusion.
1054+-- to fusion. Performs replacement on invalid scalar values.
715unfoldrN :: Int -> (a -> Maybe (Char,a)) -> a -> Text
1055unfoldrN :: Int -> (a -> Maybe (Char,a)) -> a -> Text
716−unfoldrN n f s = unstream (S.unfoldrN n f s)
1056+unfoldrN n f s = unstream (S.unfoldrN n (firstf safe . f) s)
717{-# INLINE unfoldrN #-}
1057{-# INLINE unfoldrN #-}
719-- -----------------------------------------------------------------------------
1059-- -----------------------------------------------------------------------------
@@ -726,14 +1066,16 @@ take :: Int -> Text -> Text
726take n t@(Text arr off len)
1066take n t@(Text arr off len)
727 | n <= 0 = empty
1067 | n <= 0 = empty
728 | n >= len = t
1068 | n >= len = t
729− | otherwise = Text arr off (loop 0 0)
1069+ | otherwise = text arr off (iterN n t)
732− | i >= len || cnt >= n = i
733− | otherwise = loop (i+d) (cnt+1)
735{-# INLINE [1] take #-}
1070{-# INLINE [1] take #-}
1072+iterN :: Int -> Text -> Int
1073+iterN n t@(Text _arr _off len) = loop 0 0
1075+ | i >= len || cnt >= n = i
1076+ | otherwise = loop (i+d) (cnt+1)
1077+ where d = iter_ t i
737{-# RULES
1079{-# RULES
738"TEXT take -> fused" [~1] forall n t.
1080"TEXT take -> fused" [~1] forall n t.
739 take n t = unstream (S.take n (stream t))
1081 take n t = unstream (S.take n (stream t))
@@ -741,18 +1083,36 @@ take n t@(Text arr off len)
741 unstream (S.take n (stream t)) = take n t
1083 unstream (S.take n (stream t)) = take n t
1086+-- | /O(n)/ 'takeEnd' @n@ @t@ returns the suffix remaining after
1087+-- taking @n@ characters from the end of @t@.
1091+-- > takeEnd 3 "foobar" == "bar"
1092+takeEnd :: Int -> Text -> Text
1093+takeEnd n t@(Text arr off len)
1096+ | otherwise = text arr (off+i) (len-i)
1097+ where i = iterNEnd n t
1099+iterNEnd :: Int -> Text -> Int
1100+iterNEnd n t@(Text _arr _off len) = loop (len-1) n
1104+ | otherwise = loop (i+d) (m-1)
1105+ where d = reverseIter_ t i
744-- | /O(n)/ 'drop' @n@, applied to a 'Text', returns the suffix of the
1107-- | /O(n)/ 'drop' @n@, applied to a 'Text', returns the suffix of the
745−-- 'Text' of length @n@, or the empty 'Text' if @n@ is greater than the
1108+-- 'Text' after the first @n@ characters, or the empty 'Text' if @n@
746−-- length of the 'Text'. Subject to fusion.
1109+-- is greater than the length of the 'Text'. Subject to fusion.
747drop :: Int -> Text -> Text
1110drop :: Int -> Text -> Text
748drop n t@(Text arr off len)
1111drop n t@(Text arr off len)
749 | n <= 0 = t
1112 | n <= 0 = t
750 | n >= len = empty
1113 | n >= len = empty
751− | otherwise = loop 0 0
1114+ | otherwise = text arr (off+i) (len-i)
753− | i >= len || cnt >= n = Text arr (off+i) (len-i)
754− | otherwise = loop (i+d) (cnt+1)
755− where d = iter_ t i
1115+ where i = iterN n t
756{-# INLINE [1] drop #-}
1116{-# INLINE [1] drop #-}
758{-# RULES
1118{-# RULES
@@ -762,6 +1122,18 @@ drop n t@(Text arr off len)
762 unstream (S.drop n (stream t)) = drop n t
1122 unstream (S.drop n (stream t)) = drop n t
1125+-- | /O(n)/ 'dropEnd' @n@ @t@ returns the prefix remaining after
1126+-- dropping @n@ characters from the end of @t@.
1130+-- > dropEnd 3 "foobar" == "foo"
1131+dropEnd :: Int -> Text -> Text
1132+dropEnd n t@(Text arr off len)
1135+ | otherwise = text arr off (iterNEnd n t)
765-- | /O(n)/ 'takeWhile', applied to a predicate @p@ and a 'Text',
1137-- | /O(n)/ 'takeWhile', applied to a predicate @p@ and a 'Text',
766-- returns the longest prefix (possibly empty) of elements that
1138-- returns the longest prefix (possibly empty) of elements that
767-- satisfy @p@. Subject to fusion.
1139-- satisfy @p@. Subject to fusion.
@@ -769,8 +1141,8 @@ takeWhile :: (Char -> Bool) -> Text -> Text
769takeWhile p t@(Text arr off len) = loop 0
1141takeWhile p t@(Text arr off len) = loop 0
770 where loop !i | i >= len = t
1142 where loop !i | i >= len = t
771 | p c = loop (i+d)
1143 | p c = loop (i+d)
772− | otherwise = textP arr off i
1144+ | otherwise = text arr off i
773− where (c,d) = iter t i
1145+ where Iter c d = iter t i
774{-# INLINE [1] takeWhile #-}
1146{-# INLINE [1] takeWhile #-}
776{-# RULES
1148{-# RULES
@@ -780,6 +1152,27 @@ takeWhile p t@(Text arr off len) = loop 0
780 unstream (S.takeWhile p (stream t)) = takeWhile p t
1152 unstream (S.takeWhile p (stream t)) = takeWhile p t
1155+-- | /O(n)/ 'takeWhileEnd', applied to a predicate @p@ and a 'Text',
1156+-- returns the longest suffix (possibly empty) of elements that
1157+-- satisfy @p@. Subject to fusion.
1160+-- > takeWhileEnd (=='o') "foo" == "oo"
1161+takeWhileEnd :: (Char -> Bool) -> Text -> Text
1162+takeWhileEnd p t@(Text arr off len) = loop (len-1) len
1163+ where loop !i !l | l <= 0 = t
1164+ | p c = loop (i+d) (l+d)
1165+ | otherwise = text arr (off+l) (len-l)
1166+ where (c,d) = reverseIter t i
1167+{-# INLINE [1] takeWhileEnd #-}
1170+"TEXT takeWhileEnd -> fused" [~1] forall p t.
1171+ takeWhileEnd p t = S.reverse (S.takeWhile p (S.reverseStream t))
1172+"TEXT takeWhileEnd -> unfused" [1] forall p t.
1173+ S.reverse (S.takeWhile p (S.reverseStream t)) = takeWhileEnd p t
783-- | /O(n)/ 'dropWhile' @p@ @t@ returns the suffix remaining after
1176-- | /O(n)/ 'dropWhile' @p@ @t@ returns the suffix remaining after
784-- 'takeWhile' @p@ @t@. Subject to fusion.
1177-- 'takeWhile' @p@ @t@. Subject to fusion.
785dropWhile :: (Char -> Bool) -> Text -> Text
1178dropWhile :: (Char -> Bool) -> Text -> Text
@@ -787,7 +1180,7 @@ dropWhile p t@(Text arr off len) = loop 0 0
787 where loop !i !l | l >= len = empty
1180 where loop !i !l | l >= len = empty
788 | p c = loop (i+d) (l+d)
1181 | p c = loop (i+d) (l+d)
789 | otherwise = Text arr (off+i) (len-l)
1182 | otherwise = Text arr (off+i) (len-l)
790− where (c,d) = iter t i
1183+ where Iter c d = iter t i
791{-# INLINE [1] dropWhile #-}
1184{-# INLINE [1] dropWhile #-}
793{-# RULES
1186{-# RULES
@@ -798,8 +1191,9 @@ dropWhile p t@(Text arr off len) = loop 0 0
800-- | /O(n)/ 'dropWhileEnd' @p@ @t@ returns the prefix remaining after
1193-- | /O(n)/ 'dropWhileEnd' @p@ @t@ returns the prefix remaining after
801−-- dropping characters that fail the predicate @p@ from the end of
1194+-- dropping characters that satisfy the predicate @p@ from the end of
802-- @t@. Subject to fusion.
1195-- @t@. Subject to fusion.
803-- Examples:
1197-- Examples:
805-- > dropWhileEnd (=='.') "foo..." == "foo"
1199-- > dropWhileEnd (=='.') "foo..." == "foo"
@@ -819,7 +1213,7 @@ dropWhileEnd p t@(Text arr off len) = loop (len-1) len
821-- | /O(n)/ 'dropAround' @p@ @t@ returns the substring remaining after
1215-- | /O(n)/ 'dropAround' @p@ @t@ returns the substring remaining after
822−-- dropping characters that fail the predicate @p@ from both the
1216+-- dropping characters that satisfy the predicate @p@ from both the
823-- beginning and end of @t@. Subject to fusion.
1217-- beginning and end of @t@. Subject to fusion.
824dropAround :: (Char -> Bool) -> Text -> Text
1218dropAround :: (Char -> Bool) -> Text -> Text
825dropAround p = dropWhile p . dropWhileEnd p
1219dropAround p = dropWhile p . dropWhileEnd p
@@ -854,31 +1248,23 @@ splitAt :: Int -> Text -> (Text, Text)
854splitAt n t@(Text arr off len)
1248splitAt n t@(Text arr off len)
855 | n <= 0 = (empty, t)
1249 | n <= 0 = (empty, t)
856 | n >= len = (t, empty)
1250 | n >= len = (t, empty)
857− | otherwise = (Text arr off k, Text arr (off+k) (len-k))
1251+ | otherwise = let k = iterN n t
858− where k = loop 0 0
1252+ in (text arr off k, text arr (off+k) (len-k))
860− | i >= len || cnt >= n = i
861− | otherwise = loop (i+d) (cnt+1)
863−{-# INLINE splitAt #-}
865−-- | /O(n)/ 'spanBy', applied to a predicate @p@ and text @t@, returns
1254+-- | /O(n)/ 'span', applied to a predicate @p@ and text @t@, returns
866-- a pair whose first element is the longest prefix (possibly empty)
1255-- a pair whose first element is the longest prefix (possibly empty)
867-- of @t@ of elements that satisfy @p@, and whose second is the
1256-- of @t@ of elements that satisfy @p@, and whose second is the
868-- remainder of the list.
1257-- remainder of the list.
869−spanBy :: (Char -> Bool) -> Text -> (Text, Text)
1258+span :: (Char -> Bool) -> Text -> (Text, Text)
870−spanBy p t@(Text arr off len) = (textP arr off k, textP arr (off+k) (len-k))
1259+span p t = case span_ p t of
871− where k = loop 0
1260+ (# hd,tl #) -> (hd,tl)
872− loop !i | i >= len || not (p c) = i
873− | otherwise = loop (i+d)
874− where (c,d) = iter t i
875−{-# INLINE spanBy #-}
1261+{-# INLINE span #-}
877−-- | /O(n)/ 'breakBy' is like 'spanBy', but the prefix returned is
1263+-- | /O(n)/ 'break' is like 'span', but the prefix returned is
878-- over elements that fail the predicate @p@.
1264-- over elements that fail the predicate @p@.
879−breakBy :: (Char -> Bool) -> Text -> (Text, Text)
1265+break :: (Char -> Bool) -> Text -> (Text, Text)
880−breakBy p = spanBy (not . p)
1266+break p = span (not . p)
881−{-# INLINE breakBy #-}
1267+{-# INLINE break #-}
883-- | /O(n)/ Group characters in a string according to a predicate.
1269-- | /O(n)/ Group characters in a string according to a predicate.
884groupBy :: (Char -> Char -> Bool) -> Text -> [Text]
1270groupBy :: (Char -> Char -> Bool) -> Text -> [Text]
@@ -887,7 +1273,7 @@ groupBy p = loop
887 loop t@(Text arr off len)
1273 loop t@(Text arr off len)
888 | null t = []
1274 | null t = []
889 | otherwise = text arr off n : loop (text arr (off+n) (len-n))
1275 | otherwise = text arr off n : loop (text arr (off+n) (len-n))
890− where (c,d) = iter t 0
1276+ where Iter c d = iter t 0
891 n = d + findAIndexOrEnd (not . p c) (Text arr (off+d) (len-d))
1277 n = d + findAIndexOrEnd (not . p c) (Text arr (off+d) (len-d))
893-- | Returns the /array/ index (in units of 'Word16') at which a
1279-- | Returns the /array/ index (in units of 'Word16') at which a
@@ -897,8 +1283,8 @@ findAIndexOrEnd :: (Char -> Bool) -> Text -> Int
897findAIndexOrEnd q t@(Text _arr _off len) = go 0
1283findAIndexOrEnd q t@(Text _arr _off len) = go 0
898 where go !i | i >= len || q c = i
1284 where go !i | i >= len || q c = i
899 | otherwise = go (i+d)
1285 | otherwise = go (i+d)
900− where (c,d) = iter t i
1286+ where Iter c d = iter t i
902-- | /O(n)/ Group characters in a string by equality.
1288-- | /O(n)/ Group characters in a string by equality.
903group :: Text -> [Text]
1289group :: Text -> [Text]
904group = groupBy (==)
1290group = groupBy (==)
@@ -922,36 +1308,43 @@ tails t | null t = [empty]
922-- copies to create substrings; they just construct new 'Text's that
1308-- copies to create substrings; they just construct new 'Text's that
923-- are slices of the original.
1309-- are slices of the original.
925−-- | /O(m+n)/ Break a 'Text' into pieces separated by the first
1311+-- | /O(m+n)/ Break a 'Text' into pieces separated by the first 'Text'
926−-- 'Text' argument, consuming the delimiter. An empty delimiter is
1312+-- argument (which cannot be empty), consuming the delimiter. An empty
927−-- invalid, and will cause an error to be raised.
1313+-- delimiter is invalid, and will cause an error to be raised.
929-- Examples:
1315-- Examples:
931−-- > split "\r\n" "a\r\nb\r\nd\r\ne" == ["a","b","d","e"]
1317+-- > splitOn "\r\n" "a\r\nb\r\nd\r\ne" == ["a","b","d","e"]
932−-- > split "aaa" "aaaXaaaXaaaXaaa" == ["","X","X","X",""]
1318+-- > splitOn "aaa" "aaaXaaaXaaaXaaa" == ["","X","X","X",""]
933−-- > split "x" "x" == ["",""]
1319+-- > splitOn "x" "x" == ["",""]
937−-- > intercalate s . split s == id
1323+-- > intercalate s . splitOn s == id
938−-- > split (singleton c) == splitBy (==c)
1324+-- > splitOn (singleton c) == split (==c)
1326+-- (Note: the string @s@ to split on above cannot be empty.)
940-- In (unlikely) bad cases, this function's time complexity degrades
1328-- In (unlikely) bad cases, this function's time complexity degrades
941-- towards /O(n*m)/.
1329-- towards /O(n*m)/.
942−split :: Text -> Text -> [Text]
1330+splitOn :: Text
1331+ -- ^ String to split on. If this string is empty, an error
943−split pat@(Text _ _ l) src@(Text arr off len)
1336+splitOn pat@(Text _ _ l) src@(Text arr off len)
944− | l <= 0 = emptyError "split"
1337+ | l <= 0 = emptyError "splitOn"
945− | isSingleton pat = splitBy (== unsafeHead pat) src
1338+ | isSingleton pat = split (== unsafeHead pat) src
946 | otherwise = go 0 (indices pat src)
1339 | otherwise = go 0 (indices pat src)
948− go !s (x:xs) = textP arr (s+off) (x-s) : go (x+l) xs
1341+ go !s (x:xs) = text arr (s+off) (x-s) : go (x+l) xs
949− go s _ = [textP arr (s+off) (len-s)]
1342+ go s _ = [text arr (s+off) (len-s)]
950−{-# INLINE [1] split #-}
1343+{-# INLINE [1] splitOn #-}
952{-# RULES
1345{-# RULES
953−"TEXT split/singleton -> splitBy/==" [~1] forall c t.
1346+"TEXT splitOn/singleton -> split/==" [~1] forall c t.
954− split (singleton c) t = splitBy (==c) t
1347+ splitOn (singleton c) t = split (==c) t
957-- | /O(n)/ Splits a 'Text' into components delimited by separators,
1350-- | /O(n)/ Splits a 'Text' into components delimited by separators,
@@ -959,15 +1352,15 @@ split pat@(Text _ _ l) src@(Text arr off len)
959-- resulting components do not contain the separators. Two adjacent
1352-- resulting components do not contain the separators. Two adjacent
960-- separators result in an empty component in the output. eg.
1353-- separators result in an empty component in the output. eg.
962−-- > splitBy (=='a') "aabbaca" == ["","","bb","c",""]
1355+-- > split (=='a') "aabbaca" == ["","","bb","c",""]
963−-- > splitBy (=='a') "" == [""]
1356+-- > split (=='a') "" == [""]
964−splitBy :: (Char -> Bool) -> Text -> [Text]
1357+split :: (Char -> Bool) -> Text -> [Text]
965−splitBy _ t@(Text _off _arr 0) = [t]
1358+split _ t@(Text _off _arr 0) = [t]
966−splitBy p t = loop t
1359+split p t = loop t
967 where loop s | null s' = [l]
1360 where loop s | null s' = [l]
968 | otherwise = l : loop (unsafeTail s')
1361 | otherwise = l : loop (unsafeTail s')
969− where (l, s') = breakBy p s
1362+ where (# l, s' #) = span_ (not . p) s
970−{-# INLINE splitBy #-}
1363+{-# INLINE split #-}
972-- | /O(n)/ Splits a 'Text' into components of length @k@. The last
1365-- | /O(n)/ Splits a 'Text' into components of length @k@. The last
973-- element may be shorter than the other chunks, depending on the
1366-- element may be shorter than the other chunks, depending on the
@@ -989,21 +1382,21 @@ chunksOf k = go
989-------------------------------------------------------------------------------
1382-------------------------------------------------------------------------------
990-- ** Searching with a predicate
1383-- ** Searching with a predicate
992−-- | /O(n)/ The 'findBy' function takes a predicate and a 'Text', and
1385+-- | /O(n)/ The 'find' function takes a predicate and a 'Text', and
993−-- returns the first element in matching the predicate, or 'Nothing'
1386+-- returns the first element matching the predicate, or 'Nothing' if
994−-- if there is no such element.
1387+-- there is no such element.
995−findBy :: (Char -> Bool) -> Text -> Maybe Char
1388+find :: (Char -> Bool) -> Text -> Maybe Char
996−findBy p t = S.findBy p (stream t)
1389+find p t = S.findBy p (stream t)
997−{-# INLINE findBy #-}
1390+{-# INLINE find #-}
999−-- | /O(n)/ The 'partitionBy' function takes a predicate and a 'Text',
1392+-- | /O(n)/ The 'partition' function takes a predicate and a 'Text',
1000-- and returns the pair of 'Text's with elements which do and do not
1393-- and returns the pair of 'Text's with elements which do and do not
1001-- satisfy the predicate, respectively; i.e.
1394-- satisfy the predicate, respectively; i.e.
1003−-- > partitionBy p t == (filter p t, filter (not . p) t)
1396+-- > partition p t == (filter p t, filter (not . p) t)
1004−partitionBy :: (Char -> Bool) -> Text -> (Text, Text)
1397+partition :: (Char -> Bool) -> Text -> (Text, Text)
1005−partitionBy p t = (filter p t, filter (not . p) t)
1398+partition p t = (filter p t, filter (not . p) t)
1006−{-# INLINE partitionBy #-}
1399+{-# INLINE partition #-}
1008-- | /O(n)/ 'filter', applied to a predicate and a 'Text',
1401-- | /O(n)/ 'filter', applied to a predicate and a 'Text',
1009-- returns a 'Text' containing those characters that satisfy the
1402-- returns a 'Text' containing those characters that satisfy the
@@ -1019,71 +1412,69 @@ filter p t = unstream (S.filter p (stream t))
1020-- Examples:
1413-- Examples:
1022−-- > break "::" "a::b::c" ==> ("a", "::b::c")
1415+-- > breakOn "::" "a::b::c" ==> ("a", "::b::c")
1023−-- > break "/" "foobar" ==> ("foobar", "")
1416+-- > breakOn "/" "foobar" ==> ("foobar", "")
1027-- > append prefix match == haystack
1420-- > append prefix match == haystack
1028−-- > where (prefix, match) = break needle haystack
1421+-- > where (prefix, match) = breakOn needle haystack
1030-- If you need to break a string by a substring repeatedly (e.g. you
1423-- If you need to break a string by a substring repeatedly (e.g. you
1031−-- want to break on every instance of a substring), use 'find'
1424+-- want to break on every instance of a substring), use 'breakOnAll'
1032-- instead, as it has lower startup overhead.
1425-- instead, as it has lower startup overhead.
1034-- In (unlikely) bad cases, this function's time complexity degrades
1427-- In (unlikely) bad cases, this function's time complexity degrades
1035-- towards /O(n*m)/.
1428-- towards /O(n*m)/.
1036−break :: Text -> Text -> (Text, Text)
1429+breakOn :: Text -> Text -> (Text, Text)
1037−break pat src@(Text arr off len)
1430+breakOn pat src@(Text arr off len)
1038− | null pat = emptyError "break"
1431+ | null pat = emptyError "breakOn"
1039 | otherwise = case indices pat src of
1432 | otherwise = case indices pat src of
1040 [] -> (src, empty)
1433 [] -> (src, empty)
1041− (x:_) -> (textP arr off x, textP arr (off+x) (len-x))
1434+ (x:_) -> (text arr off x, text arr (off+x) (len-x))
1042−{-# INLINE break #-}
1435+{-# INLINE breakOn #-}
1044−-- | /O(n+m)/ Similar to 'break', but searches from the end of the string.
1437+-- | /O(n+m)/ Similar to 'breakOn', but searches from the end of the
1046-- The first element of the returned tuple is the prefix of @haystack@
1440-- The first element of the returned tuple is the prefix of @haystack@
1047-- up to and including the last match of @needle@. The second is the
1441-- up to and including the last match of @needle@. The second is the
1048-- remainder of @haystack@, following the match.
1442-- remainder of @haystack@, following the match.
1050−-- > breakEnd "::" "a::b::c" ==> ("a::b::", "c")
1444+-- > breakOnEnd "::" "a::b::c" ==> ("a::b::", "c")
1051−breakEnd :: Text -> Text -> (Text, Text)
1445+breakOnEnd :: Text -> Text -> (Text, Text)
1446+breakOnEnd pat src = (reverse b, reverse a)
1052−breakEnd pat src = let (a,b) = break (reverse pat) (reverse src)
1447+ where (a,b) = breakOn (reverse pat) (reverse src)
1053− in (reverse b, reverse a)
1054−{-# INLINE breakEnd #-}
1448+{-# INLINE breakOnEnd #-}
1056-- | /O(n+m)/ Find all non-overlapping instances of @needle@ in
1450-- | /O(n+m)/ Find all non-overlapping instances of @needle@ in
1057−-- @haystack@. The first element of the returned pair is the prefix
1451+-- @haystack@. Each element of the returned list consists of a pair:
1058−-- of @haystack@ prior to any matches of @needle@. The second is a
1452+--
1059−-- list of pairs.
1453+-- * The entire string prior to the /k/th match (i.e. the prefix)
1061−-- The first element of each pair in the list is a span from the
1455+-- * The /k/th match, followed by the remainder of the string
1062−-- beginning of a match to the beginning of the next match, while the
1063−-- second is a span from the beginning of the match to the end of the
1066-- Examples:
1457-- Examples:
1068−-- > find "::" ""
1459+-- > breakOnAll "::" ""
1069−-- > ==> ("", [])
1460+-- > ==> []
1070−-- > find "/" "a/b/c/d"
1461+-- > breakOnAll "/" "a/b/c/"
1071−-- > ==> ("a", [("/b","/b/c/d"), ("/c","/c/d"), ("/d","/d")])
1462+-- > ==> [("a", "/b/c/"), ("a/b", "/c/"), ("a/b/c", "/")]
1073-- In (unlikely) bad cases, this function's time complexity degrades
1464-- In (unlikely) bad cases, this function's time complexity degrades
1074-- towards /O(n*m)/.
1465-- towards /O(n*m)/.
1467+-- The @needle@ parameter may not be empty.
1468+breakOnAll :: Text -- ^ @needle@ to search for
1469+ -> Text -- ^ @haystack@ in which to search
1075−find :: Text -> Text -> (Text, [(Text, Text)])
1470+ -> [(Text, Text)]
1076−find pat src@(Text arr off len)
1471+breakOnAll pat src@(Text arr off slen)
1077− | null pat = emptyError "find"
1472+ | null pat = emptyError "breakOnAll"
1078− | otherwise = case indices pat src of
1473+ | otherwise = L.map step (indices pat src)
1080− (x:xs) -> (chunk 0 x, go x xs)
1082− go !s (x:xs) = (chunk s (x-s), chunk s (len-s)) : go x xs
1475+ step x = (chunk 0 x, chunk x (slen-x))
1083− go s _ = let c = chunk s (len-s)
1085− chunk !n !l = textP arr (n+off) l
1476+ chunk !n !l = text arr (n+off) l
1086−{-# INLINE find #-}
1477+{-# INLINE breakOnAll #-}
1088-------------------------------------------------------------------------------
1479-------------------------------------------------------------------------------
1089-- ** Indexing 'Text's
1480-- ** Indexing 'Text's
@@ -1102,7 +1493,7 @@ find pat src@(Text arr off len)
1102-- For example, suppose you have a string that you want to split on
1493-- For example, suppose you have a string that you want to split on
1103-- the substring @\"::\"@, such as @\"foo::bar::quux\"@. Instead of
1494-- the substring @\"::\"@, such as @\"foo::bar::quux\"@. Instead of
1104-- searching for the index of @\"::\"@ and taking the substrings
1495-- searching for the index of @\"::\"@ and taking the substrings
1105−-- before and after that index, you would instead use @find \"::\"@.
1496+-- before and after that index, you would instead use @breakOnAll \"::\"@.
1107-- | /O(n)/ 'Text' index (subscript) operator, starting from 0.
1498-- | /O(n)/ 'Text' index (subscript) operator, starting from 0.
1108index :: Text -> Int -> Char
1499index :: Text -> Int -> Char
@@ -1149,13 +1540,15 @@ countChar c t = S.countChar c (stream t)
1149-- equivalent to a pair of 'unpack' operations.
1540-- equivalent to a pair of 'unpack' operations.
1150zip :: Text -> Text -> [(Char,Char)]
1541zip :: Text -> Text -> [(Char,Char)]
1151zip a b = S.unstreamList $ S.zipWith (,) (stream a) (stream b)
1542zip a b = S.unstreamList $ S.zipWith (,) (stream a) (stream b)
1152−{-# INLINE [0] zip #-}
1543+{-# INLINE zip #-}
1154-- | /O(n)/ 'zipWith' generalises 'zip' by zipping with the function
1545-- | /O(n)/ 'zipWith' generalises 'zip' by zipping with the function
1155-- given as the first argument, instead of a tupling function.
1546-- given as the first argument, instead of a tupling function.
1547+-- Performs replacement on invalid scalar values.
1156zipWith :: (Char -> Char -> Char) -> Text -> Text -> Text
1548zipWith :: (Char -> Char -> Char) -> Text -> Text -> Text
1157−zipWith f t1 t2 = unstream (S.zipWith f (stream t1) (stream t2))
1549+zipWith f t1 t2 = unstream (S.zipWith g (stream t1) (stream t2))
1550+ where g a b = safe (f a b)
1158−{-# INLINE [0] zipWith #-}
1551+{-# INLINE zipWith #-}
1160-- | /O(n)/ Breaks a 'Text' up into a list of words, delimited by 'Char's
1553-- | /O(n)/ Breaks a 'Text' up into a list of words, delimited by 'Char's
1161-- representing white space.
1554-- representing white space.
@@ -1171,7 +1564,7 @@ words t@(Text arr off len) = loop 0 0
1171 then loop (start+1) (start+1)
1564 then loop (start+1) (start+1)
1172 else Text arr (start+off) (n-start) : loop (n+d) (n+d)
1565 else Text arr (start+off) (n-start) : loop (n+d) (n+d)
1173 | otherwise = loop start (n+d)
1566 | otherwise = loop start (n+d)
1174− where (c,d) = iter t n
1567+ where Iter c d = iter t n
1175{-# INLINE words #-}
1568{-# INLINE words #-}
1177-- | /O(n)/ Breaks a 'Text' up into a list of 'Text's at
1570-- | /O(n)/ Breaks a 'Text' up into a list of 'Text's at
@@ -1181,7 +1574,7 @@ lines ps | null ps = []
1181 | otherwise = h : if null t
1574 | otherwise = h : if null t
1183 else lines (unsafeTail t)
1576 else lines (unsafeTail t)
1184− where (h,t) = spanBy (/= '\n') ps
1577+ where (# h,t #) = span_ (/= '\n') ps
1185{-# INLINE lines #-}
1578{-# INLINE lines #-}
@@ -1218,8 +1611,7 @@ unwords = intercalate (singleton ' ')
1218{-# INLINE unwords #-}
1611{-# INLINE unwords #-}
1220-- | /O(n)/ The 'isPrefixOf' function takes two 'Text's and returns
1613-- | /O(n)/ The 'isPrefixOf' function takes two 'Text's and returns
1221−-- 'True' iff the first is a prefix of the second. This function is
1614+-- 'True' iff the first is a prefix of the second. Subject to fusion.
1222−-- subject to fusion.
1223isPrefixOf :: Text -> Text -> Bool
1615isPrefixOf :: Text -> Text -> Bool
1224isPrefixOf a@(Text _ _ alen) b@(Text _ _ blen) =
1616isPrefixOf a@(Text _ _ alen) b@(Text _ _ blen) =
1225 alen <= blen && S.isPrefixOf (stream a) (stream b)
1617 alen <= blen && S.isPrefixOf (stream a) (stream b)
@@ -1228,8 +1620,6 @@ isPrefixOf a@(Text _ _ alen) b@(Text _ _ blen) =
1228{-# RULES
1620{-# RULES
1229"TEXT isPrefixOf -> fused" [~1] forall s t.
1621"TEXT isPrefixOf -> fused" [~1] forall s t.
1230 isPrefixOf s t = S.isPrefixOf (stream s) (stream t)
1622 isPrefixOf s t = S.isPrefixOf (stream s) (stream t)
1231−"TEXT isPrefixOf -> unfused" [1] forall s t.
1232− S.isPrefixOf (stream s) (stream t) = isPrefixOf s t
1235-- | /O(n)/ The 'isSuffixOf' function takes two 'Text's and returns
1625-- | /O(n)/ The 'isSuffixOf' function takes two 'Text's and returns
@@ -1260,5 +1650,106 @@ isInfixOf needle haystack
1260 isInfixOf (singleton n) h = S.elem n (S.stream h)
1650 isInfixOf (singleton n) h = S.elem n (S.stream h)
1653+-------------------------------------------------------------------------------
1656+-- | /O(n)/ Return the suffix of the second string if its prefix
1657+-- matches the entire first string.
1661+-- > stripPrefix "foo" "foobar" == Just "bar"
1662+-- > stripPrefix "" "baz" == Just "baz"
1663+-- > stripPrefix "foo" "quux" == Nothing
1665+-- This is particularly useful with the @ViewPatterns@ extension to
1668+-- > {-# LANGUAGE ViewPatterns #-}
1669+-- > import Data.Text as T
1671+-- > fnordLength :: Text -> Int
1672+-- > fnordLength (stripPrefix "fnord" -> Just suf) = T.length suf
1673+-- > fnordLength _ = -1
1674+stripPrefix :: Text -> Text -> Maybe Text
1675+stripPrefix p@(Text _arr _off plen) t@(Text arr off len)
1676+ | p `isPrefixOf` t = Just $! text arr (off+plen) (len-plen)
1677+ | otherwise = Nothing
1679+-- | /O(n)/ Find the longest non-empty common prefix of two strings
1680+-- and return it, along with the suffixes of each string at which they
1683+-- If the strings do not have a common prefix or either one is empty,
1684+-- this function returns 'Nothing'.
1688+-- > commonPrefixes "foobar" "fooquux" == Just ("foo","bar","quux")
1689+-- > commonPrefixes "veeble" "fetzer" == Nothing
1690+-- > commonPrefixes "" "baz" == Nothing
1691+commonPrefixes :: Text -> Text -> Maybe (Text,Text,Text)
1692+commonPrefixes t0@(Text arr0 off0 len0) t1@(Text arr1 off1 len1) = go 0 0
1694+ go !i !j | i < len0 && j < len1 && a == b = go (i+d0) (j+d1)
1695+ | i > 0 = Just (Text arr0 off0 i,
1696+ text arr0 (off0+i) (len0-i),
1697+ text arr1 (off1+j) (len1-j))
1698+ | otherwise = Nothing
1699+ where Iter a d0 = iter t0 i
1700+ Iter b d1 = iter t1 j
1702+-- | /O(n)/ Return the prefix of the second string if its suffix
1703+-- matches the entire first string.
1707+-- > stripSuffix "bar" "foobar" == Just "foo"
1708+-- > stripSuffix "" "baz" == Just "baz"
1709+-- > stripSuffix "foo" "quux" == Nothing
1711+-- This is particularly useful with the @ViewPatterns@ extension to
1714+-- > {-# LANGUAGE ViewPatterns #-}
1715+-- > import Data.Text as T
1717+-- > quuxLength :: Text -> Int
1718+-- > quuxLength (stripSuffix "quux" -> Just pre) = T.length pre
1719+-- > quuxLength _ = -1
1720+stripSuffix :: Text -> Text -> Maybe Text
1721+stripSuffix p@(Text _arr _off plen) t@(Text arr off len)
1722+ | p `isSuffixOf` t = Just $! text arr off (len-plen)
1723+ | otherwise = Nothing
1725+-- | Add a list of non-negative numbers. Errors out on overflow.
1726+sumP :: String -> [Int] -> Int
1729+ | ax >= 0 = go ax xs
1730+ | otherwise = overflowError fun
1263emptyError :: String -> a
1734emptyError :: String -> a
1264−emptyError fun = P.error ("Data.Text." ++ fun ++ ": empty input")
1735+emptyError fun = P.error $ "Data.Text." ++ fun ++ ": empty input"
1737+overflowError :: String -> a
1738+overflowError fun = P.error $ "Data.Text." ++ fun ++ ": size overflow"
1740+-- | /O(n)/ Make a distinct copy of the given string, sharing no
1741+-- storage with the original string.
1743+-- As an example, suppose you read a large string, of which you need
1744+-- only a small portion. If you do not use 'copy', the entire original
1745+-- array will be kept alive in memory by the smaller string. Making a
1746+-- copy \"breaks the link\" to the original array, allowing it to be
1747+-- garbage collected if there are no other live references to it.
1748+copy :: Text -> Text
1749+copy (Text arr off len) = Text (A.run go) 0 len
1751+ go :: ST s (A.MArray s)
1754+ A.copyI marr 0 arr off len