@@ -1,5 +1,11 @@
11{-# LANGUAGE BangPatterns, CPP, MagicHash, Rank2Types, UnboxedTuples #-}
22{-# OPTIONS_GHC -fno-warn-orphans #-}
3+#if __GLASGOW_HASKELL__ >= 702
4+{-# LANGUAGE Trustworthy #-}
5+#endif
6+#if __GLASGOW_HASKELL__ >= 708
7+{-# LANGUAGE TypeFamilies #-}
8+#endif
39
410-- |
511-- Module : Data.Text
@@ -8,8 +14,7 @@
814-- (c) 2008, 2009 Tom Harper
915--
1016-- License : BSD-style
11−-- Maintainer : bos@serpentine.com, rtomharper@googlemail.com,
12−-- duncan@haskell.org
17+-- Maintainer : bos@serpentine.com
1318-- Stability : experimental
1419-- Portability : GHC
1520--
@@ -27,8 +32,8 @@
2732--
2833-- To use an extended and very rich family of functions for working
2934-- with Unicode text (including normalization, regular expressions,
30−-- non-standard encodings, text breaking, and locales), see the
31−-- @text-icu@ package: <http://hackage.haskell.org/package/text-icu>
35+-- non-standard encodings, text breaking, and locales), see
36+-- <http://hackage.haskell.org/package/text-icu the text-icu package >.
3237
3338module Data.Text
3439 (
@@ -76,6 +81,7 @@ module Data.Text
7681 , toCaseFold
7782 , toLower
7883 , toUpper
84+ , toTitle
7985
8086 -- ** Justification
8187 , justifyLeft
@@ -119,8 +125,11 @@ module Data.Text
119125
120126 -- ** Breaking strings
121127 , take
128+ , takeEnd
122129 , drop
130+ , dropEnd
123131 , takeWhile
132+ , takeWhileEnd
124133 , dropWhile
125134 , dropWhileEnd
126135 , dropAround
@@ -167,95 +176,110 @@ module Data.Text
167176 , partition
168177
169178 -- , findSubstring
170−
179+
171180 -- * Indexing
172181 -- $index
173182 , index
174183 , findIndex
175184 , count
176185
177− -- * Zipping and unzipping
186+ -- * Zipping
178187 , zip
179188 , zipWith
180189
181190 -- -* Ordered text
182191 -- , sort
192+
193+ -- * Low level operations
194+ , copy
195+ , unpackCString#
183196 ) where
184197
185198import Prelude (Char, Bool(..), Int, Maybe(..), String,
186199 Eq(..), Ord(..), Ordering(..), (++),
187− Read(..), Show(..),
188− (&&), (||), (+), (-), (.), ($), ($!), (>>), (*),
189− div, maxBound, not, return, otherwise)
200+ Read(..),
201+ (&&), (||), (+), (-), (.), ($), ($!), (>>),
202+ not, return, otherwise, quot)
190203#if defined(HAVE_DEEPSEQ)
191−import Control.DeepSeq (NFData)
204+import Control.DeepSeq (NFData(rnf))
192205#endif
193206#if defined(ASSERTS)
194207import Control.Exception (assert)
195208#endif
196209import Data.Char (isSpace)
197−import Data.Data (Data(gfoldl, toConstr, gunfold, dataTypeOf))
198−#if __GLASGOW_HASKELL__ >= 612
199−import Data.Data (mkNoRepType)
200−#else
201−import Data.Data (mkNorepType)
202−#endif
210+import Data.Data (Data(gfoldl, toConstr, gunfold, dataTypeOf), constrIndex,
211+ Constr, mkConstr, DataType, mkDataType, Fixity(Prefix))
203212import Control.Monad (foldM)
213+import Control.Monad.ST (ST)
204214import qualified Data.Text.Array as A
205215import qualified Data.List as L
216+import Data.Binary (Binary(get, put))
206217import Data.Monoid (Monoid(..))
218+#if MIN_VERSION_base(4,9,0)
219+import Data.Semigroup (Semigroup(..))
220+#endif
207221import Data.String (IsString(..))
208−import qualified Data.Text.Fusion as S
209−import qualified Data.Text.Fusion.Common as S
210−import Data.Text.Fusion (stream, reverseStream, unstream)
211−import Data.Text.Private (span_)
212−import Data.Text.Internal (Text(..), empty, firstf, safe, text, textP)
222+import qualified Data.Text.Internal.Fusion as S
223+import qualified Data.Text.Internal.Fusion.Common as S
224+import Data.Text.Encoding (decodeUtf8', encodeUtf8)
225+import Data.Text.Internal.Fusion (stream, reverseStream, unstream)
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#)
213229import qualified Prelude as P
214230import Data.Text.Unsafe (Iter(..), iter, iter_, lengthWord16, reverseIter,
215− unsafeHead, unsafeTail)
216−import Data.Text.UnsafeChar (unsafeChr)
217−import qualified Data.Text.Util as U
218−import qualified Data.Text.Encoding.Utf16 as U16
219−import Data.Text.Search (indices)
231+ reverseIter_, unsafeHead, unsafeTail)
232+import Data.Text.Internal.Unsafe.Char (unsafeChr)
233+import qualified Data.Text.Internal.Functions as F
234+import qualified Data.Text.Internal.Encoding.Utf16 as U16
235+import Data.Text.Internal.Search (indices)
220236#if defined(__HADDOCK__)
221237import Data.ByteString (ByteString)
222238import qualified Data.Text.Lazy as L
223239import Data.Int (Int64)
224240#endif
225−import qualified GHC.CString as GHC
226−import GHC.Prim (Addr#)
241+import GHC.Base (eqInt, neInt, gtInt, geInt, ltInt, leInt)
242+#if __GLASGOW_HASKELL__ >= 708
243+import qualified GHC.Exts as Exts
244+#endif
245+#if MIN_VERSION_base(4,7,0)
246+import Text.Printf (PrintfArg, formatArg, formatString)
247+#endif
227248
228249-- $strict
229250--
230251-- This package provides both strict and lazy 'Text' types. The
231−-- strict type is provided by the 'Data.Text' package, while the lazy
232−-- type is provided by the 'Data.Text.Lazy' package. Internally, 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
233254-- lazy @Text@ type consists of a list of strict chunks.
234255--
235256-- The strict 'Text' type requires that an entire string fit into
236−-- memory at once. The lazy @Text@ type is capable of streaming
237−-- strings that are larger than memory using a small memory footprint.
238−-- In many cases, the overhead of chunked streaming makes the lazy
239−-- @Text@ type slower than its strict counterpart, but this is not
240−-- always the case. Sometimes, the time complexity of a function in
241−-- one module may be different from the other, due to their differing
242−-- internal structures.
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.
243264--
244265-- Each module provides an almost identical API, with the main
245266-- difference being that the strict module uses 'Int' values for
246−-- lengths and counts, while the lazy module uses 'Int64' lengths.
267+-- lengths and counts, while the lazy module uses 'Data.Int.Int64'
268+-- lengths.
247269
248270-- $replacement
249271--
250272-- A 'Text' value is a sequence of Unicode scalar values, as defined
251−-- in §3.9, definition D76 of the Unicode 5.2 standard:
252−-- <http://www.unicode.org/versions/Unicode5.2.0/ch03.pdf#page=35>. As
253−-- such, a 'Text' cannot contain values in the range U+D800 to U+DFFF
254−-- inclusive. Haskell implementations admit all Unicode code points
255−-- (§3.4, definition D10) as 'Char' values, including code points
256−-- from this invalid range. This means that there are some 'Char'
257−-- values that are not valid Unicode scalar values, and the functions
258−-- in this module must handle those cases.
273+-- in
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
277+-- points
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
282+-- those cases.
259283--
260284-- Within this module, many functions construct a 'Text' from one or
261285-- more 'Char' values. Those functions will substitute 'Char' values
@@ -269,8 +293,8 @@ import GHC.Prim (Addr#)
269293-- range U+D800 through U+DFFF are used by UTF-16 to denote surrogate
270294-- code points, and so cannot be represented. The functions replace
271295-- invalid scalar values, instead of dropping them, as a security
272−-- measure. For details, see Unicode Technical Report 36, §3.5:
273−-- <http://unicode.org/reports/tr36/#Deletion_of_Noncharacters>)
296+-- measure. For details, see
297+-- <http://unicode.org/reports/tr36/#Deletion_of_Noncharacters Unicode Technical Report 36, §3.5 >.)
274298
275299-- $fusion
276300--
@@ -288,11 +312,11 @@ import GHC.Prim (Addr#)
288312-- > countChars = T.length . T.toUpper . E.decodeUtf8
289313--
290314-- From the type signatures involved, this looks like it should
291−-- allocate one 'ByteString' value, and two 'Text' values. However,
292−-- when a module is compiled with optimisation enabled under GHC, the
293−-- two intermediate 'Text' values will be optimised away, and the
294−-- function will be compiled down to a single loop over the source
295−-- 'ByteString'.
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'.
296320--
297321-- Functions that can be fused by the compiler are documented with the
298322-- phrase \"Subject to fusion\".
@@ -306,46 +330,83 @@ instance Eq Text where
306330instance Ord Text where
307331 compare = compareText
308332
309−instance Show Text where
310− showsPrec p ps r = showsPrec p (unpack ps) r
311−
312333instance Read Text where
313334 readsPrec p str = [(pack x,y) | (x,y) <- readsPrec p str]
314335
336+#if MIN_VERSION_base(4,9,0)
337+-- Semigroup orphan instances for older GHCs are provided by
338+-- 'semigroups` package
339+
340+instance Semigroup Text where
341+ (<>) = append
342+#endif
343+
315344instance Monoid Text where
316345 mempty = empty
346+#if MIN_VERSION_base(4,9,0)
347+ mappend = (<>) -- future-proof definition
348+#else
317349 mappend = append
350+#endif
318351 mconcat = concat
319352
320353instance IsString Text where
321354 fromString = pack
322355
356+#if __GLASGOW_HASKELL__ >= 708
357+instance Exts.IsList Text where
358+ type Item Text = Char
359+ fromList = pack
360+ toList = unpack
361+#endif
362+
323363#if defined(HAVE_DEEPSEQ)
324−instance NFData Text
364+instance NFData Text where rnf !_ = ()
325365#endif
326366
327−-- This instance preserves data abstraction at the cost of inefficiency.
367+instance Binary Text where
368+ put t = put (encodeUtf8 t)
369+ get = do
370+ bs <- get
371+ case decodeUtf8' bs of
372+ P.Left exn -> P.fail (P.show exn)
373+ P.Right a -> P.return a
374+
375+-- | This instance preserves data abstraction at the cost of inefficiency.
328376-- We omit reflection services for the sake of data abstraction.
329−--
330−-- This instance was created by copying the behavior of Data.Set and
331−-- Data.Map. If you feel a mistake has been made, please feel free to
332−-- submit improvements.
333377--
334−-- Original discussion is archived here:
335−
336−-- "could we get a Data instance for Data.Text.Text?"
337−-- http://groups.google.com/group/haskell-cafe/browse_thread/thread/b5bbb1b28a7e525d/0639d46852575b93
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
381+-- improvements.
382+--
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? >
385+--
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, ... >
338389
339390instance Data Text where
340391 gfoldl f z txt = z pack `f` (unpack txt)
341− toConstr _ = P.error "Data.Text.Text.toConstr"
342− gunfold _ _ = P.error "Data.Text.Text.gunfold"
343−#if __GLASGOW_HASKELL__ >= 612
344− dataTypeOf _ = mkNoRepType "Data.Text.Text"
345−#else
346− dataTypeOf _ = mkNorepType "Data.Text.Text"
392+ toConstr _ = packConstr
393+ gunfold k z c = case constrIndex c of
394+ 1 -> k (z pack)
395+ _ -> P.error "gunfold"
396+ dataTypeOf _ = textDataType
397+
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
347402#endif
348403
404+packConstr :: Constr
405+packConstr = mkConstr textDataType "pack" [] Prefix
406+
407+textDataType :: DataType
408+textDataType = mkDataType "Data.Text.Text" [packConstr]
409+
349410-- | /O(n)/ Compare two 'Text' values lexicographically.
350411compareText :: Text -> Text -> Ordering
351412compareText ta@(Text _arrA _offA lenA) tb@(Text _arrB _offB lenB)
@@ -366,33 +427,9 @@ compareText ta@(Text _arrA _offA lenA) tb@(Text _arrB _offB lenB)
366427-- | /O(n)/ Convert a 'String' into a 'Text'. Subject to
367428-- fusion. Performs replacement on invalid scalar values.
368429pack :: String -> Text
369−pack = unstream . S.streamList . L.map safe
430+pack = unstream . S.map safe . S.streamList
370431{-# INLINE [1] pack #-}
371432
372−-- | /O(n)/ Convert a Text into a String. Subject to fusion.
373−unpack :: Text -> String
374−unpack = S.unstreamList . stream
375−{-# INLINE [1] unpack #-}
376−
377−-- | /O(n)/ Convert a literal string into a Text.
378−unpackCString# :: Addr# -> Text
379−unpackCString# addr# = unstream (S.streamCString# addr#)
380−{-# NOINLINE unpackCString# #-}
381−
382−{-# RULES "TEXT literal" forall a.
383− unstream (S.streamList (L.map safe (GHC.unpackCString# a)))
384− = unpackCString# a #-}
385−
386−{-# RULES "TEXT literal UTF8" forall a.
387− unstream (S.streamList (L.map safe (GHC.unpackCStringUtf8# a)))
388− = unpackCString# a #-}
389−
390−-- | /O(1)/ Convert a character into a Text. Subject to fusion.
391−-- Performs replacement on invalid scalar values.
392−singleton :: Char -> Text
393−singleton = unstream . S.singleton . safe
394−{-# INLINE [1] singleton #-}
395−
396433-- -----------------------------------------------------------------------------
397434-- * Basic functions
398435
@@ -423,12 +460,13 @@ append a@(Text arr1 off1 len1) b@(Text arr2 off2 len2)
423460 | otherwise = overflowError "append"
424461 where
425462 len = len1+len2
463+ x :: ST s (A.MArray s)
426464 x = do
427465 arr <- A.new len
428466 A.copyI arr 0 arr1 off1 len1
429467 A.copyI arr len1 arr2 off2 len
430468 return arr
431−{-# INLINE append #-}
469+{-# NOINLINE append #-}
432470
433471{-# RULES
434472"TEXT append -> fused" [~1] forall t1 t2.
@@ -448,8 +486,8 @@ head t = S.head (stream t)
448486uncons :: Text -> Maybe (Char, Text)
449487uncons t@(Text arr off len)
450488 | len <= 0 = Nothing
451− | otherwise = Just (c, textP arr (off+d) (len-d))
452− where Iter c d = iter t 0
489+ | otherwise = Just $ let !(Iter c d) = iter t 0
490+ in (c, text arr (off+d) (len-d))
453491{-# INLINE [1] uncons #-}
454492
455493-- | Lifted from Control.Arrow and specialized.
@@ -479,7 +517,7 @@ last (Text arr off len)
479517tail :: Text -> Text
480518tail t@(Text arr off len)
481519 | len <= 0 = emptyError "tail"
482− | otherwise = textP arr (off+d) (len-d)
520+ | otherwise = text arr (off+d) (len-d)
483521 where d = iter_ t 0
484522{-# INLINE [1] tail #-}
485523
@@ -494,8 +532,8 @@ tail t@(Text arr off len)
494532-- be non-empty. Subject to fusion.
495533init :: Text -> Text
496534init (Text arr off len) | len <= 0 = emptyError "init"
497− | n >= 0xDC00 && n <= 0xDFFF = textP arr off (len-2)
498− | otherwise = textP arr off (len-1)
535+ | n >= 0xDC00 && n <= 0xDFFF = text arr off (len-2)
536+ | otherwise = text arr off (len-1)
499537 where
500538 n = A.unsafeIndex arr (off+len-1)
501539{-# INLINE [1] init #-}
@@ -534,7 +572,9 @@ isSingleton = S.isSingleton . stream
534572-- Subject to fusion.
535573length :: Text -> Int
536574length t = S.length (stream t)
537−{-# 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.
538578
539579-- | /O(n)/ Compare the count of characters in a 'Text' to a number.
540580-- Subject to fusion.
@@ -553,32 +593,32 @@ compareLength t n = S.compareLengthI (stream t) n
553593
554594{-# RULES
555595"TEXT ==N/length -> compareLength/==EQ" [~1] forall t n.
556− (==) (length t) n = compareLength t n == EQ
596+ eqInt (length t) n = compareLength t n == EQ
557597 #-}
558598
559599{-# RULES
560600"TEXT /=N/length -> compareLength//=EQ" [~1] forall t n.
561− (/=) (length t) n = compareLength t n /= EQ
601+ neInt (length t) n = compareLength t n /= EQ
562602 #-}
563603
564604{-# RULES
565605"TEXT <N/length -> compareLength/==LT" [~1] forall t n.
566− (<) (length t) n = compareLength t n == LT
606+ ltInt (length t) n = compareLength t n == LT
567607 #-}
568608
569609{-# RULES
570610"TEXT <=N/length -> compareLength//=GT" [~1] forall t n.
571− (<=) (length t) n = compareLength t n /= GT
611+ leInt (length t) n = compareLength t n /= GT
572612 #-}
573613
574614{-# RULES
575615"TEXT >N/length -> compareLength/==GT" [~1] forall t n.
576− (>) (length t) n = compareLength t n == GT
616+ gtInt (length t) n = compareLength t n == GT
577617 #-}
578618
579619{-# RULES
580620"TEXT >=N/length -> compareLength//=LT" [~1] forall t n.
581− (>=) (length t) n = compareLength t n /= LT
621+ geInt (length t) n = compareLength t n /= LT
582622 #-}
583623
584624-- -----------------------------------------------------------------------------
@@ -594,7 +634,7 @@ map f t = unstream (S.map (safe . f) (stream t))
594634-- 'Text's and concatenates the list after interspersing the first
595635-- argument between each element of the list.
596636intercalate :: Text -> [Text] -> Text
597−intercalate t = concat . (U.intersperse t)
637+intercalate t = concat . (F.intersperse t)
598638{-# INLINE intercalate #-}
599639
600640-- | /O(n)/ The 'intersperse' function takes a character and places it
@@ -609,16 +649,59 @@ reverse :: Text -> Text
609649reverse t = S.reverse (stream t)
610650{-# INLINE reverse #-}
611651
612−-- | /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@.
654+--
655+-- This function behaves as though it was defined as follows:
656+--
657+-- @
658+-- replace needle replacement haystack =
659+-- 'intercalate' replacement ('splitOn' needle haystack)
660+-- @
661+--
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:
665+--
666+-- > replace "oo" "foo" "oo" == "foo"
667+--
668+-- In cases where several instances of @needle@ overlap, only the
669+-- first one will be replaced:
670+--
671+-- > replace "ofo" "bar" "ofofo" == "barfo"
613672--
614673-- In (unlikely) bad cases, this function's time complexity degrades
615674-- towards /O(n*m)/.
616−replace :: Text -- ^ Text to search for
617− -> Text -- ^ Replacement text
618− -> Text -- ^ Input text
675+replace :: Text
676+ -- ^ @needle@ to search for. If this string is empty, an
677+ -- error will occur.
619678 -> Text
620−replace s d = intercalate d . splitOn s
621−{-# INLINE replace #-}
679+ -- ^ @replacement@ to replace @needle@ with.
680+ -> Text
681+ -- ^ @haystack@ in which to search.
682+ -> Text
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
689+ | otherwise = empty
690+ where
691+ ixs = indices needle haystack
692+ len = hayLen - (neeLen - repLen) `mul` L.length ixs
693+ x :: ST s (A.MArray s)
694+ x = do
695+ marr <- A.new len
696+ let loop (i:is) o d = do
697+ let d0 = d + i - o
698+ d1 = d0 + repLen
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
703+ loop ixs 0 0
704+ return marr
622705
623706-- ----------------------------------------------------------------------------
624707-- ** Case conversions (folds)
@@ -637,13 +720,13 @@ replace s d = intercalate d . splitOn s
637720-- /Note/: In some languages, case conversion is a locale- and
638721-- context-dependent operation. The case conversion functions in this
639722-- module are /not/ locale sensitive. Programs that require locale
640−-- sensitivity should use appropriate versions of the case mapping
641−-- functions from the @text-icu@ package:
642−-- <http://hackage.haskell.org/package/text-icu>
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 >.
643725
644−-- | /O(n)/ Convert a string to folded case. This function is mainly
645−-- useful for performing caseless (also known as case insensitive)
646−-- string comparisons.
726+-- | /O(n)/ Convert a string to folded case. Subject to fusion.
727+--
728+-- This function is mainly useful for performing caseless (also known
729+-- as case insensitive) string comparisons.
647730--
648731-- A string @x@ is a caseless match for a string @y@ if and only if:
649732--
@@ -658,25 +741,51 @@ replace s d = intercalate d . splitOn s
658741-- instead of itself.
659742toCaseFold :: Text -> Text
660743toCaseFold t = unstream (S.toCaseFold (stream t))
661−{-# INLINE [0] toCaseFold #-}
744+{-# INLINE toCaseFold #-}
662745
663746-- | /O(n)/ Convert a string to lower case, using simple case
664−-- conversion. The result string may be longer than the input string.
665−-- For instance, \"İ\" (Latin capital letter I with dot above,
666−-- U+0130) maps to the sequence \"i\" (Latin small letter i, U+0069) followed
667−-- by \" ̇\" (combining dot above, U+0307).
747+-- conversion. Subject to fusion.
748+--
749+-- The result string may be longer than the input string. For
750+-- instance, \"İ\" (Latin capital letter I with dot above,
751+-- U+0130) maps to the sequence \"i\" (Latin small letter i, U+0069)
752+-- followed by \" ̇\" (combining dot above, U+0307).
668753toLower :: Text -> Text
669754toLower t = unstream (S.toLower (stream t))
670755{-# INLINE toLower #-}
671756
672757-- | /O(n)/ Convert a string to upper case, using simple case
673−-- conversion. The result string may be longer than the input string.
674−-- For instance, the German \"ß\" (eszett, U+00DF) maps to the
758+-- conversion. Subject to fusion.
759+--
760+-- The result string may be longer than the input string. For
761+-- instance, the German \"ß\" (eszett, U+00DF) maps to the
675762-- two-letter sequence \"SS\".
676763toUpper :: Text -> Text
677764toUpper t = unstream (S.toUpper (stream t))
678765{-# INLINE toUpper #-}
679766
767+-- | /O(n)/ Convert a string to title case, using simple case
768+-- conversion. Subject to fusion.
769+--
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
773+-- to lower case.
774+--
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).
779+--
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 #-}
788+
680789-- | /O(n)/ Left-justify a string to the given length, using the
681790-- specified fill character on the right. Subject to fusion.
682791-- Performs replacement on invalid scalar values.
@@ -727,7 +836,7 @@ center k c t
727836 | otherwise = replicateChar l c `append` t `append` replicateChar r c
728837 where len = length t
729838 d = k - len
730− r = d `div` 2
839+ r = d `quot` 2
731840 l = d - r
732841{-# INLINE center #-}
733842
@@ -792,6 +901,7 @@ concat ts = case ts' of
792901 where
793902 ts' = L.filter (not . null) ts
794903 len = sumP "concat" $ L.map lengthWord16 ts'
904+ go :: ST s (A.MArray s)
795905 go = do
796906 arr <- A.new len
797907 let step i (Text a o l) =
@@ -805,13 +915,13 @@ concatMap f = concat . foldr ((:) . f) []
805915{-# INLINE concatMap #-}
806916
807917-- | /O(n)/ 'any' @p@ @t@ determines whether any character in the
808−-- 'Text' @t@ satisifes the predicate @p@. Subject to fusion.
918+-- 'Text' @t@ satisfies the predicate @p@. Subject to fusion.
809919any :: (Char -> Bool) -> Text -> Bool
810920any p t = S.any p (stream t)
811921{-# INLINE any #-}
812922
813923-- | /O(n)/ 'all' @p@ @t@ determines whether all characters in the
814−-- 'Text' @t@ satisify the predicate @p@. Subject to fusion.
924+-- 'Text' @t@ satisfy the predicate @p@. Subject to fusion.
815925all :: (Char -> Bool) -> Text -> Bool
816926all p t = S.all p (stream t)
817927{-# INLINE all #-}
@@ -899,13 +1009,13 @@ mapAccumR f z0 = second reverse . S.mapAccumL g z0 . reverseStream
8991009-- @t@ repeated @n@ times.
9001010replicate :: Int -> Text -> Text
9011011replicate n t@(Text a o l)
902− | n <= 0 || l <= 0 = empty
903− | n == 1 = t
904− | isSingleton t = replicateChar n (unsafeHead t)
905− | n <= maxBound `div` l = Text (A.run x) 0 len
906− | otherwise = overflowError "replicate"
1012+ | n <= 0 || l <= 0 = empty
1013+ | n == 1 = t
1014+ | isSingleton t = replicateChar n (unsafeHead t)
1015+ | otherwise = Text (A.run x) 0 len
9071016 where
908− len = l * n
1017+ len = l `mul` n
1018+ x :: ST s (A.MArray s)
9091019 x = do
9101020 arr <- A.new len
9111021 let loop !d !i | i >= n = return arr
@@ -956,14 +1066,16 @@ take :: Int -> Text -> Text
9561066take n t@(Text arr off len)
9571067 | n <= 0 = empty
9581068 | n >= len = t
959− | otherwise = Text arr off (loop 0 0)
960− where
961− loop !i !cnt
962− | i >= len || cnt >= n = i
963− | otherwise = loop (i+d) (cnt+1)
964− where d = iter_ t i
1069+ | otherwise = text arr off (iterN n t)
9651070{-# INLINE [1] take #-}
9661071
1072+iterN :: Int -> Text -> Int
1073+iterN n t@(Text _arr _off len) = loop 0 0
1074+ where loop !i !cnt
1075+ | i >= len || cnt >= n = i
1076+ | otherwise = loop (i+d) (cnt+1)
1077+ where d = iter_ t i
1078+
9671079{-# RULES
9681080"TEXT take -> fused" [~1] forall n t.
9691081 take n t = unstream (S.take n (stream t))
@@ -971,6 +1083,27 @@ take n t@(Text arr off len)
9711083 unstream (S.take n (stream t)) = take n t
9721084 #-}
9731085
1086+-- | /O(n)/ 'takeEnd' @n@ @t@ returns the suffix remaining after
1087+-- taking @n@ characters from the end of @t@.
1088+--
1089+-- Examples:
1090+--
1091+-- > takeEnd 3 "foobar" == "bar"
1092+takeEnd :: Int -> Text -> Text
1093+takeEnd n t@(Text arr off len)
1094+ | n <= 0 = empty
1095+ | n >= len = t
1096+ | otherwise = text arr (off+i) (len-i)
1097+ where i = iterNEnd n t
1098+
1099+iterNEnd :: Int -> Text -> Int
1100+iterNEnd n t@(Text _arr _off len) = loop (len-1) n
1101+ where loop i !m
1102+ | i <= 0 = 0
1103+ | m <= 1 = i
1104+ | otherwise = loop (i+d) (m-1)
1105+ where d = reverseIter_ t i
1106+
9741107-- | /O(n)/ 'drop' @n@, applied to a 'Text', returns the suffix of the
9751108-- 'Text' after the first @n@ characters, or the empty 'Text' if @n@
9761109-- is greater than the length of the 'Text'. Subject to fusion.
@@ -978,11 +1111,8 @@ drop :: Int -> Text -> Text
9781111drop n t@(Text arr off len)
9791112 | n <= 0 = t
9801113 | n >= len = empty
981− | otherwise = loop 0 0
982− where loop !i !cnt
983− | i >= len || cnt >= n = Text arr (off+i) (len-i)
984− | otherwise = loop (i+d) (cnt+1)
985− where d = iter_ t i
1114+ | otherwise = text arr (off+i) (len-i)
1115+ where i = iterN n t
9861116{-# INLINE [1] drop #-}
9871117
9881118{-# RULES
@@ -992,6 +1122,18 @@ drop n t@(Text arr off len)
9921122 unstream (S.drop n (stream t)) = drop n t
9931123 #-}
9941124
1125+-- | /O(n)/ 'dropEnd' @n@ @t@ returns the prefix remaining after
1126+-- dropping @n@ characters from the end of @t@.
1127+--
1128+-- Examples:
1129+--
1130+-- > dropEnd 3 "foobar" == "foo"
1131+dropEnd :: Int -> Text -> Text
1132+dropEnd n t@(Text arr off len)
1133+ | n <= 0 = t
1134+ | n >= len = empty
1135+ | otherwise = text arr off (iterNEnd n t)
1136+
9951137-- | /O(n)/ 'takeWhile', applied to a predicate @p@ and a 'Text',
9961138-- returns the longest prefix (possibly empty) of elements that
9971139-- satisfy @p@. Subject to fusion.
@@ -999,7 +1141,7 @@ takeWhile :: (Char -> Bool) -> Text -> Text
9991141takeWhile p t@(Text arr off len) = loop 0
10001142 where loop !i | i >= len = t
10011143 | p c = loop (i+d)
1002− | otherwise = textP arr off i
1144+ | otherwise = text arr off i
10031145 where Iter c d = iter t i
10041146{-# INLINE [1] takeWhile #-}
10051147
@@ -1010,6 +1152,27 @@ takeWhile p t@(Text arr off len) = loop 0
10101152 unstream (S.takeWhile p (stream t)) = takeWhile p t
10111153 #-}
10121154
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.
1158+-- Examples:
1159+--
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 #-}
1168+
1169+{-# RULES
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
1174+ #-}
1175+
10131176-- | /O(n)/ 'dropWhile' @p@ @t@ returns the suffix remaining after
10141177-- 'takeWhile' @p@ @t@. Subject to fusion.
10151178dropWhile :: (Char -> Bool) -> Text -> Text
@@ -1028,8 +1191,9 @@ dropWhile p t@(Text arr off len) = loop 0 0
10281191 #-}
10291192
10301193-- | /O(n)/ 'dropWhileEnd' @p@ @t@ returns the prefix remaining after
1031−-- dropping characters that fail the predicate @p@ from the end of
1194+-- dropping characters that satisfy the predicate @p@ from the end of
10321195-- @t@. Subject to fusion.
1196+--
10331197-- Examples:
10341198--
10351199-- > dropWhileEnd (=='.') "foo..." == "foo"
@@ -1049,7 +1213,7 @@ dropWhileEnd p t@(Text arr off len) = loop (len-1) len
10491213 #-}
10501214
10511215-- | /O(n)/ 'dropAround' @p@ @t@ returns the substring remaining after
1052−-- dropping characters that fail the predicate @p@ from both the
1216+-- dropping characters that satisfy the predicate @p@ from both the
10531217-- beginning and end of @t@. Subject to fusion.
10541218dropAround :: (Char -> Bool) -> Text -> Text
10551219dropAround p = dropWhile p . dropWhileEnd p
@@ -1084,13 +1248,8 @@ splitAt :: Int -> Text -> (Text, Text)
10841248splitAt n t@(Text arr off len)
10851249 | n <= 0 = (empty, t)
10861250 | n >= len = (t, empty)
1087− | otherwise = (Text arr off k, Text arr (off+k) (len-k))
1088− where k = loop 0 0
1089− loop !i !cnt
1090− | i >= len || cnt >= n = i
1091− | otherwise = loop (i+d) (cnt+1)
1092− where d = iter_ t i
1093−{-# INLINE splitAt #-}
1251+ | otherwise = let k = iterN n t
1252+ in (text arr off k, text arr (off+k) (len-k))
10941253
10951254-- | /O(n)/ 'span', applied to a predicate @p@ and text @t@, returns
10961255-- a pair whose first element is the longest prefix (possibly empty)
@@ -1125,7 +1284,7 @@ findAIndexOrEnd q t@(Text _arr _off len) = go 0
11251284 where go !i | i >= len || q c = i
11261285 | otherwise = go (i+d)
11271286 where Iter c d = iter t i
1128−
1287+
11291288-- | /O(n)/ Group characters in a string by equality.
11301289group :: Text -> [Text]
11311290group = groupBy (==)
@@ -1149,31 +1308,38 @@ tails t | null t = [empty]
11491308-- copies to create substrings; they just construct new 'Text's that
11501309-- are slices of the original.
11511310
1152−-- | /O(m+n)/ Break a 'Text' into pieces separated by the first
1153−-- 'Text' argument, consuming the delimiter. An empty delimiter is
1154−-- invalid, and will cause an error to be raised.
1311+-- | /O(m+n)/ Break a 'Text' into pieces separated by the first 'Text'
1312+-- argument (which cannot be empty), consuming the delimiter. An empty
1313+-- delimiter is invalid, and will cause an error to be raised.
11551314--
11561315-- Examples:
11571316--
11581317-- > splitOn "\r\n" "a\r\nb\r\nd\r\ne" == ["a","b","d","e"]
11591318-- > splitOn "aaa" "aaaXaaaXaaaXaaa" == ["","X","X","X",""]
11601319-- > splitOn "x" "x" == ["",""]
1161−--
1320+--
11621321-- and
11631322--
11641323-- > intercalate s . splitOn s == id
11651324-- > splitOn (singleton c) == split (==c)
11661325--
1326+-- (Note: the string @s@ to split on above cannot be empty.)
1327+--
11671328-- In (unlikely) bad cases, this function's time complexity degrades
11681329-- towards /O(n*m)/.
1169−splitOn :: Text -> Text -> [Text]
1330+splitOn :: Text
1331+ -- ^ String to split on. If this string is empty, an error
1332+ -- will occur.
1333+ -> Text
1334+ -- ^ Input text.
1335+ -> [Text]
11701336splitOn pat@(Text _ _ l) src@(Text arr off len)
11711337 | l <= 0 = emptyError "splitOn"
11721338 | isSingleton pat = split (== unsafeHead pat) src
11731339 | otherwise = go 0 (indices pat src)
11741340 where
1175− go !s (x:xs) = textP arr (s+off) (x-s) : go (x+l) xs
1176− go s _ = [textP arr (s+off) (len-s)]
1341+ go !s (x:xs) = text arr (s+off) (x-s) : go (x+l) xs
1342+ go s _ = [text arr (s+off) (len-s)]
11771343{-# INLINE [1] splitOn #-}
11781344
11791345{-# RULES
@@ -1265,7 +1431,7 @@ breakOn pat src@(Text arr off len)
12651431 | null pat = emptyError "breakOn"
12661432 | otherwise = case indices pat src of
12671433 [] -> (src, empty)
1268− (x:_) -> (textP arr off x, textP arr (off+x) (len-x))
1434+ (x:_) -> (text arr off x, text arr (off+x) (len-x))
12691435{-# INLINE breakOn #-}
12701436
12711437-- | /O(n+m)/ Similar to 'breakOn', but searches from the end of the
@@ -1307,7 +1473,7 @@ breakOnAll pat src@(Text arr off slen)
13071473 | otherwise = L.map step (indices pat src)
13081474 where
13091475 step x = (chunk 0 x, chunk x (slen-x))
1310− chunk !n !l = textP arr (n+off) l
1476+ chunk !n !l = text arr (n+off) l
13111477{-# INLINE breakOnAll #-}
13121478
13131479-------------------------------------------------------------------------------
@@ -1374,7 +1540,7 @@ countChar c t = S.countChar c (stream t)
13741540-- equivalent to a pair of 'unpack' operations.
13751541zip :: Text -> Text -> [(Char,Char)]
13761542zip a b = S.unstreamList $ S.zipWith (,) (stream a) (stream b)
1377−{-# INLINE [0] zip #-}
1543+{-# INLINE zip #-}
13781544
13791545-- | /O(n)/ 'zipWith' generalises 'zip' by zipping with the function
13801546-- given as the first argument, instead of a tupling function.
@@ -1382,7 +1548,7 @@ zip a b = S.unstreamList $ S.zipWith (,) (stream a) (stream b)
13821548zipWith :: (Char -> Char -> Char) -> Text -> Text -> Text
13831549zipWith f t1 t2 = unstream (S.zipWith g (stream t1) (stream t2))
13841550 where g a b = safe (f a b)
1385−{-# INLINE [0] zipWith #-}
1551+{-# INLINE zipWith #-}
13861552
13871553-- | /O(n)/ Breaks a 'Text' up into a list of words, delimited by 'Char's
13881554-- representing white space.
@@ -1507,7 +1673,7 @@ isInfixOf needle haystack
15071673-- > fnordLength _ = -1
15081674stripPrefix :: Text -> Text -> Maybe Text
15091675stripPrefix p@(Text _arr _off plen) t@(Text arr off len)
1510− | p `isPrefixOf` t = Just $! textP arr (off+plen) (len-plen)
1676+ | p `isPrefixOf` t = Just $! text arr (off+plen) (len-plen)
15111677 | otherwise = Nothing
15121678
15131679-- | /O(n)/ Find the longest non-empty common prefix of two strings
@@ -1527,8 +1693,8 @@ commonPrefixes t0@(Text arr0 off0 len0) t1@(Text arr1 off1 len1) = go 0 0
15271693 where
15281694 go !i !j | i < len0 && j < len1 && a == b = go (i+d0) (j+d1)
15291695 | i > 0 = Just (Text arr0 off0 i,
1530− textP arr0 (off0+i) (len0-i),
1531− textP arr1 (off1+j) (len1-j))
1696+ text arr0 (off0+i) (len0-i),
1697+ text arr1 (off1+j) (len1-j))
15321698 | otherwise = Nothing
15331699 where Iter a d0 = iter t0 i
15341700 Iter b d1 = iter t1 j
@@ -1553,7 +1719,7 @@ commonPrefixes t0@(Text arr0 off0 len0) t1@(Text arr1 off1 len1) = go 0 0
15531719-- > quuxLength _ = -1
15541720stripSuffix :: Text -> Text -> Maybe Text
15551721stripSuffix p@(Text _arr _off plen) t@(Text arr off len)
1556− | p `isSuffixOf` t = Just $! textP arr off (len-plen)
1722+ | p `isSuffixOf` t = Just $! text arr off (len-plen)
15571723 | otherwise = Nothing
15581724
15591725-- | Add a list of non-negative numbers. Errors out on overflow.
@@ -1570,3 +1736,20 @@ emptyError fun = P.error $ "Data.Text." ++ fun ++ ": empty input"
15701736
15711737overflowError :: String -> a
15721738overflowError fun = P.error $ "Data.Text." ++ fun ++ ": size overflow"
1739+
1740+-- | /O(n)/ Make a distinct copy of the given string, sharing no
1741+-- storage with the original string.
1742+--
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
1750+ where
1751+ go :: ST s (A.MArray s)
1752+ go = do
1753+ marr <- A.new len
1754+ A.copyI marr 0 arr off len
1755+ return marr