@@ -1,48 +1,29 @@
1−{-# LANGUAGE BangPatterns, CPP, MagicHash, Rank2Types, UnboxedTuples #-}
1+{-# LANGUAGE BangPatterns #-}
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
93
104-- |
115-- Module : Data.Text
12−-- Copyright : (c) 2009, 2010, 2011, 2012 Bryan O'Sullivan,
13−-- (c) 2009 Duncan Coutts,
14−-- (c) 2008, 2009 Tom Harper
6+-- Copyright : (c) Tom Harper 2008-2009,
7+-- (c) Bryan O'Sullivan 2009,
8+-- (c) Duncan Coutts 2009
159--
1610-- License : BSD-style
17−-- Maintainer : bos@serpentine.com
11+-- Maintainer : bos@serpentine.com, rtharper@aftereternity.co.uk,
12+-- duncan@haskell.org
1813-- Stability : experimental
1914-- Portability : GHC
2015--
21−-- A time and space-efficient implementation of Unicode text.
22−-- Suitable for performance critical use, both in terms of large data
23−-- quantities and high speed.
24−--
25−-- /Note/: Read below the synopsis for important notes on the use of
26−-- this module.
16+-- A time and space-efficient implementation of Unicode text using
17+-- packed Word16 arrays. Suitable for performance critical use, both
18+-- in terms of large data quantities and high speed.
2719--
2820-- This module is intended to be imported @qualified@, to avoid name
2921-- clashes with "Prelude" functions, e.g.
3022--
3123-- > import qualified Data.Text as T
32−--
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 >.
3724
3825module Data.Text
3926 (
40− -- * Strict vs lazy types
41− -- $strict
42−
43− -- * Acceptable data
44− -- $replacement
45−
4627 -- * Fusion
4728 -- $fusion
4829
@@ -66,7 +47,6 @@ module Data.Text
6647 , init
6748 , null
6849 , length
69− , compareLength
7050
7151 -- * Transformations
7252 , map
@@ -81,7 +61,6 @@ module Data.Text
8161 , toCaseFold
8262 , toLower
8363 , toUpper
84− , toTitle
8564
8665 -- ** Justification
8766 , justifyLeft
@@ -118,6 +97,7 @@ module Data.Text
11897
11998 -- ** Generation and unfolding
12099 , replicate
100+ , replicateChar
121101 , unfoldr
122102 , unfoldrN
123103
@@ -125,11 +105,8 @@ module Data.Text
125105
126106 -- ** Breaking strings
127107 , take
128− , takeEnd
129108 , drop
130− , dropEnd
131109 , takeWhile
132− , takeWhileEnd
133110 , dropWhile
134111 , dropWhileEnd
135112 , dropAround
@@ -137,10 +114,9 @@ module Data.Text
137114 , stripStart
138115 , stripEnd
139116 , splitAt
140− , breakOn
141− , breakOnEnd
117+ , spanBy
142118 , break
143− , span
119+ , breakBy
144120 , group
145121 , groupBy
146122 , inits
@@ -148,8 +124,8 @@ module Data.Text
148124
149125 -- ** Breaking into many substrings
150126 -- $split
151− , splitOn
152127 , split
128+ , splitBy
153129 , chunksOf
154130
155131 -- ** Breaking into lines and words
@@ -164,309 +140,132 @@ module Data.Text
164140 , isSuffixOf
165141 , isInfixOf
166142
167− -- ** View patterns
168− , stripPrefix
169− , stripSuffix
170− , commonPrefixes
171−
172143 -- * Searching
144+ , elem
173145 , filter
174− , breakOnAll
175146 , find
176− , partition
147+ , findBy
148+ , partitionBy
177149
178150 -- , findSubstring
179−
151+
180152 -- * Indexing
181153 -- $index
182154 , index
183155 , findIndex
184156 , count
185157
186− -- * Zipping
158+ -- * Zipping and unzipping
187159 , zip
188160 , zipWith
189161
190162 -- -* Ordered text
191163 -- , sort
192−
193− -- * Low level operations
194− , copy
195− , unpackCString#
196164 ) where
197165
198−import Prelude (Char, Bool(..), Int, Maybe(..), String,
199− Eq(..), Ord(..), Ordering(..), (++),
200− Read(..),
201− (&&), (||), (+), (-), (.), ($), ($!), (>>),
202− not, return, otherwise, quot)
203−#if defined(HAVE_DEEPSEQ)
204−import Control.DeepSeq (NFData(rnf))
205−#endif
206−#if defined(ASSERTS)
166+import Prelude (Char, Bool(..), Functor(..), Int, Maybe(..), String,
167+ Eq(..), Ord(..), (++),
168+ Read(..), Show(..),
169+ (&&), (||), (+), (-), (.), ($),
170+ fromIntegral, div, not, return, otherwise)
207171import Control.Exception (assert)
208−#endif
209172import Data.Char (isSpace)
210−import Data.Data (Data(gfoldl, toConstr, gunfold, dataTypeOf), constrIndex,
211− Constr, mkConstr, DataType, mkDataType, Fixity(Prefix))
212−import Control.Monad (foldM)
213173import Control.Monad.ST (ST)
214174import qualified Data.Text.Array as A
215175import qualified Data.List as L
216−import Data.Binary (Binary(get, put))
217176import Data.Monoid (Monoid(..))
218−#if MIN_VERSION_base(4,9,0)
219−import Data.Semigroup (Semigroup(..))
220−#endif
177+import Data.Word (Word16)
221178import Data.String (IsString(..))
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#)
179+import qualified Data.Text.Fusion as S
180+import qualified Data.Text.Fusion.Common as S
181+import Data.Text.Fusion (stream, reverseStream, unstream)
182+import Data.Text.Internal (Text(..), empty, text, textP)
229183import qualified Prelude as P
230−import Data.Text.Unsafe (Iter(..), iter, iter_, lengthWord16, reverseIter,
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)
236−#if defined(__HADDOCK__)
237−import Data.ByteString (ByteString)
238−import qualified Data.Text.Lazy as L
239−import Data.Int (Int64)
240−#endif
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
248−
249−-- $strict
250−--
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.
255−--
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.
264−--
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'
268−-- lengths.
269−
270−-- $replacement
271−--
272−-- A 'Text' value is a sequence of Unicode scalar values, as defined
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.
283−--
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\".
290−--
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 >.)
184+import Data.Text.Unsafe (iter, iter_, reverseIter, unsafeHead, unsafeTail)
185+import Data.Text.UnsafeChar (unsafeChr)
186+import qualified Data.Text.Encoding.Utf16 as U16
187+import Data.Text.Search (indices)
298188
299189-- $fusion
300190--
301191-- Most of the functions in this module are subject to /fusion/,
302192-- meaning that a pipeline of such functions will usually allocate at
303193-- most one 'Text' value.
304−--
305−-- As an example, consider the following pipeline:
306−--
307−-- > import Data.Text as T
308−-- > import Data.Text.Encoding as E
309−-- > import Data.ByteString (ByteString)
310−-- >
311−-- > countChars :: ByteString -> Int
312−-- > countChars = T.length . T.toUpper . E.decodeUtf8
313−--
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'.
320−--
321−-- Functions that can be fused by the compiler are documented with the
322−-- phrase \"Subject to fusion\".
323194
324195instance Eq Text where
325− Text arrA offA lenA == Text arrB offB lenB
326− | lenA == lenB = A.equal arrA offA arrB offB lenA
327− | otherwise = False
196+ t1 == t2 = stream t1 == stream t2
328197 {-# INLINE (==) #-}
329198
330199instance Ord Text where
331− compare = compareText
200+ compare t1 t2 = compare (stream t1) (stream t2)
201+ {-# INLINE compare #-}
202+
203+instance Show Text where
204+ showsPrec p ps r = showsPrec p (unpack ps) r
332205
333206instance Read Text where
334207 readsPrec p str = [(pack x,y) | (x,y) <- readsPrec p str]
335208
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−
344209instance Monoid Text where
345210 mempty = empty
346−#if MIN_VERSION_base(4,9,0)
347− mappend = (<>) -- future-proof definition
348−#else
349211 mappend = append
350−#endif
351212 mconcat = concat
352213
353214instance IsString Text where
354215 fromString = pack
355216
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−
363−#if defined(HAVE_DEEPSEQ)
364−instance NFData Text where rnf !_ = ()
365−#endif
366−
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.
376−-- We omit reflection services for the sake of data abstraction.
377−--
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, ... >
389−
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
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
402−#endif
403−
404−packConstr :: Constr
405−packConstr = mkConstr textDataType "pack" [] Prefix
406−
407−textDataType :: DataType
408−textDataType = mkDataType "Data.Text.Text" [packConstr]
409−
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
415− where
416− go !i !j
417− | i >= lenA || j >= lenB = compare lenA lenB
418− | a < b = LT
419− | a > b = GT
420− | otherwise = go (i+di) (j+dj)
421− where Iter a di = iter ta i
422− Iter b dj = iter tb j
423−
424217-- -----------------------------------------------------------------------------
425218-- * Conversion to/from 'Text'
426219
427−-- | /O(n)/ Convert a 'String' into a 'Text'. Subject to
428−-- fusion. Performs replacement on invalid scalar values.
220+-- | /O(n)/ Convert a 'String' into a 'Text'. Subject to fusion.
429221pack :: String -> Text
430−pack = unstream . S.map safe . S.streamList
222+pack = unstream . S.streamList
431223{-# INLINE [1] pack #-}
432224
225+-- | /O(n)/ Convert a Text into a String. Subject to fusion.
226+unpack :: Text -> String
227+unpack = S.unstreamList . stream
228+{-# INLINE [1] unpack #-}
229+
230+-- | /O(1)/ Convert a character into a Text.
231+-- Subject to fusion.
232+singleton :: Char -> Text
233+singleton = unstream . S.singleton
234+{-# INLINE [1] singleton #-}
235+
433236-- -----------------------------------------------------------------------------
434237-- * Basic functions
435238
436239-- | /O(n)/ Adds a character to the front of a 'Text'. This function
437240-- is more costly than its 'List' counterpart because it requires
438−-- copying a new array. Subject to fusion. Performs replacement on
439−-- invalid scalar values.
241+-- copying a new array. Subject to fusion.
440242cons :: Char -> Text -> Text
441−cons c t = unstream (S.cons (safe c) (stream t))
243+cons c t = unstream (S.cons c (stream t))
442244{-# INLINE cons #-}
443245
444−infixr 5 `cons`
445−
446246-- | /O(n)/ Adds a character to the end of a 'Text'. This copies the
447247-- entire array in the process, unless fused. Subject to fusion.
448−-- Performs replacement on invalid scalar values.
449248snoc :: Text -> Char -> Text
450−snoc t c = unstream (S.snoc (stream t) (safe c))
249+snoc t c = unstream (S.snoc (stream t) c)
451250{-# INLINE snoc #-}
452251
453252-- | /O(n)/ Appends one 'Text' to the other by copying both of them
454253-- into a new 'Text'. Subject to fusion.
455254append :: Text -> Text -> Text
456−append a@(Text arr1 off1 len1) b@(Text arr2 off2 len2)
457− | len1 == 0 = b
458− | len2 == 0 = a
459− | len > 0 = Text (A.run x) 0 len
460− | otherwise = overflowError "append"
255+append (Text arr1 off1 len1) (Text arr2 off2 len2) = Text (A.run x) 0 len
461256 where
462257 len = len1+len2
463− x :: ST s (A.MArray s)
464258 x = do
465− arr <- A.new len
466− A.copyI arr 0 arr1 off1 len1
467− A.copyI arr len1 arr2 off2 len
259+ arr <- A.unsafeNew len :: ST s (A.MArray s Word16)
260+ copy arr1 off1 (len1+off1) arr 0
261+ copy arr2 off2 (len2+off2) arr len1
468262 return arr
469−{-# NOINLINE append #-}
263+ where
264+ copy arr i top arr' j
265+ | i >= top = return ()
266+ | otherwise = do A.unsafeWrite arr' j (arr `A.unsafeIndex` i)
267+ copy arr (i+1) top arr' (j+1)
268+{-# INLINE append #-}
470269
471270{-# RULES
472271"TEXT append -> fused" [~1] forall t1 t2.
@@ -486,14 +285,21 @@ head t = S.head (stream t)
486285uncons :: Text -> Maybe (Char, Text)
487286uncons t@(Text arr off len)
488287 | len <= 0 = Nothing
489− | otherwise = Just $ let !(Iter c d) = iter t 0
490− in (c, text arr (off+d) (len-d))
288+ | otherwise = Just (c, textP arr (off+d) (len-d))
289+ where (c,d) = iter t 0
491290{-# INLINE [1] uncons #-}
492291
493292-- | Lifted from Control.Arrow and specialized.
494293second :: (b -> c) -> (a,b) -> (a,c)
495294second f (a, b) = (a, f b)
496295
296+{-# RULES
297+"TEXT uncons -> fused" [~1] forall t.
298+ uncons t = fmap (second unstream) (S.uncons (stream t))
299+"TEXT uncons -> unfused" [1] forall t.
300+ fmap (second unstream) (S.uncons (stream t)) = uncons t
301+ #-}
302+
497303-- | /O(1)/ Returns the last character of a 'Text', which must be
498304-- non-empty. Subject to fusion.
499305last :: Text -> Char
@@ -517,7 +323,7 @@ last (Text arr off len)
517323tail :: Text -> Text
518324tail t@(Text arr off len)
519325 | len <= 0 = emptyError "tail"
520− | otherwise = text arr (off+d) (len-d)
326+ | otherwise = textP arr (off+d) (len-d)
521327 where d = iter_ t 0
522328{-# INLINE [1] tail #-}
523329
@@ -532,8 +338,8 @@ tail t@(Text arr off len)
532338-- be non-empty. Subject to fusion.
533339init :: Text -> Text
534340init (Text arr off len) | len <= 0 = emptyError "init"
535− | n >= 0xDC00 && n <= 0xDFFF = text arr off (len-2)
536− | otherwise = text arr off (len-1)
341+ | n >= 0xDC00 && n <= 0xDFFF = textP arr off (len-2)
342+ | otherwise = textP arr off (len-1)
537343 where
538344 n = A.unsafeIndex arr (off+len-1)
539345{-# INLINE [1] init #-}
@@ -548,11 +354,7 @@ init (Text arr off len) | len <= 0 = emptyError "init"
548354-- | /O(1)/ Tests whether a 'Text' is empty or not. Subject to
549355-- fusion.
550356null :: Text -> Bool
551−null (Text _arr _off len) =
552−#if defined(ASSERTS)
553− assert (len >= 0) $
554−#endif
555− len <= 0
357+null (Text _arr _off len) = assert (len >= 0) $ len <= 0
556358{-# INLINE [1] null #-}
557359
558360{-# RULES
@@ -572,76 +374,27 @@ isSingleton = S.isSingleton . stream
572374-- Subject to fusion.
573375length :: Text -> Int
574376length t = S.length (stream t)
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.
578−
579−-- | /O(n)/ Compare the count of characters in a 'Text' to a number.
580−-- Subject to fusion.
581−--
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 #-}
588−
589−{-# RULES
590−"TEXT compareN/length -> compareLength" [~1] forall t n.
591− compare (length t) n = compareLength t n
592− #-}
593−
594−{-# RULES
595−"TEXT ==N/length -> compareLength/==EQ" [~1] forall t n.
596− eqInt (length t) n = compareLength t n == EQ
597− #-}
598−
599−{-# RULES
600−"TEXT /=N/length -> compareLength//=EQ" [~1] forall t n.
601− neInt (length t) n = compareLength t n /= EQ
602− #-}
603−
604−{-# RULES
605−"TEXT <N/length -> compareLength/==LT" [~1] forall t n.
606− ltInt (length t) n = compareLength t n == LT
607− #-}
608−
609−{-# RULES
610−"TEXT <=N/length -> compareLength//=GT" [~1] forall t n.
611− leInt (length t) n = compareLength t n /= GT
612− #-}
613−
614−{-# RULES
615−"TEXT >N/length -> compareLength/==GT" [~1] forall t n.
616− gtInt (length t) n = compareLength t n == GT
617− #-}
618−
619−{-# RULES
620−"TEXT >=N/length -> compareLength//=LT" [~1] forall t n.
621− geInt (length t) n = compareLength t n /= LT
622− #-}
377+{-# INLINE length #-}
623378
624379-- -----------------------------------------------------------------------------
625380-- * Transformations
626381-- | /O(n)/ 'map' @f@ @t@ is the 'Text' obtained by applying @f@ to
627−-- each element of @t@. Subject to fusion. Performs replacement on
628−-- invalid scalar values.
382+-- each element of @t@. Subject to fusion.
629383map :: (Char -> Char) -> Text -> Text
630−map f t = unstream (S.map (safe . f) (stream t))
384+map f t = unstream (S.map f (stream t))
631385{-# INLINE [1] map #-}
632386
633387-- | /O(n)/ The 'intercalate' function takes a 'Text' and a list of
634388-- 'Text's and concatenates the list after interspersing the first
635389-- argument between each element of the list.
636390intercalate :: Text -> [Text] -> Text
637−intercalate t = concat . (F.intersperse t)
391+intercalate t ts = unstream (S.intercalate (stream t) (L.map stream ts))
638392{-# INLINE intercalate #-}
639393
640394-- | /O(n)/ The 'intersperse' function takes a character and places it
641−-- between the characters of a 'Text'. Subject to fusion. Performs
642−-- replacement on invalid scalar values.
395+-- between the characters of a 'Text'. Subject to fusion.
643396intersperse :: Char -> Text -> Text
644−intersperse c t = unstream (S.intersperse (safe c) (stream t))
397+intersperse c t = unstream (S.intersperse c (stream t))
645398{-# INLINE intersperse #-}
646399
647400-- | /O(n)/ Reverse the characters of a string. Subject to fusion.
@@ -649,59 +402,13 @@ reverse :: Text -> Text
649402reverse t = S.reverse (stream t)
650403{-# INLINE reverse #-}
651404
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"
672−--
673−-- In (unlikely) bad cases, this function's time complexity degrades
674−-- towards /O(n*m)/.
675−replace :: Text
676− -- ^ @needle@ to search for. If this string is empty, an
677− -- error will occur.
678− -> Text
679− -- ^ @replacement@ to replace @needle@ with.
680− -> Text
681− -- ^ @haystack@ in which to search.
405+-- | /O(m*n)/ Replace every occurrence of one substring with another.
406+replace :: Text -- ^ Text to search for
407+ -> Text -- ^ Replacement text
408+ -> Text -- ^ Input text
682409 -> 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
410+replace s d = intercalate d . split s
411+{-# INLINE replace #-}
705412
706413-- ----------------------------------------------------------------------------
707414-- ** Case conversions (folds)
@@ -716,17 +423,10 @@ replace needle@(Text _ _ neeLen)
716423-- case conversion rules. As a result, these functions may map one
717424-- input character to two or three output characters. For examples,
718425-- see the documentation of each function.
719−--
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 >.
725426
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.
427+-- | /O(n)/ Convert a string to folded case. This function is mainly
428+-- useful for performing caseless (also known as case insensitive)
429+-- string comparisons.
730430--
731431-- A string @x@ is a caseless match for a string @y@ if and only if:
732432--
@@ -741,56 +441,27 @@ replace needle@(Text _ _ neeLen)
741441-- instead of itself.
742442toCaseFold :: Text -> Text
743443toCaseFold t = unstream (S.toCaseFold (stream t))
744−{-# INLINE toCaseFold #-}
444+{-# INLINE [0] toCaseFold #-}
745445
746446-- | /O(n)/ Convert a string to lower case, using simple case
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).
447+-- conversion. The result string may be longer than the input string.
448+-- For instance, \"İ\" (Latin capital letter I with dot above,
449+-- U+0130) maps to the sequence \"i\" (Latin small letter i, U+0069) followed
450+-- by \" ̇\" (combining dot above, U+0307).
753451toLower :: Text -> Text
754452toLower t = unstream (S.toLower (stream t))
755453{-# INLINE toLower #-}
756454
757455-- | /O(n)/ Convert a string to upper case, using simple case
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
456+-- conversion. The result string may be longer than the input string.
457+-- For instance, the German \"ß\" (eszett, U+00DF) maps to the
762458-- two-letter sequence \"SS\".
763459toUpper :: Text -> Text
764460toUpper t = unstream (S.toUpper (stream t))
765461{-# INLINE toUpper #-}
766462
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−
789463-- | /O(n)/ Left-justify a string to the given length, using the
790−-- specified fill character on the right. Subject to fusion.
791−-- Performs replacement on invalid scalar values.
792−--
793−-- Examples:
464+-- specified fill character on the right. Subject to fusion. Examples:
794465--
795466-- > justifyLeft 7 'x' "foo" == "fooxxxx"
796467-- > justifyLeft 3 'x' "foobar" == "foobar"
@@ -809,10 +480,7 @@ justifyLeft k c t
809480 #-}
810481
811482-- | /O(n)/ Right-justify a string to the given length, using the
812−-- specified fill character on the left. Performs replacement on
813−-- invalid scalar values.
814−--
815−-- Examples:
483+-- specified fill character on the left. Examples:
816484--
817485-- > justifyRight 7 'x' "bar" == "xxxxbar"
818486-- > justifyRight 3 'x' "foobar" == "foobar"
@@ -823,11 +491,8 @@ justifyRight k c t
823491 where len = length t
824492{-# INLINE justifyRight #-}
825493
826−-- | /O(n)/ Center a string to the given length, using the specified
827−-- fill character on either side. Performs replacement on invalid
828−-- scalar values.
829−--
830−-- Examples:
494+-- | /O(n)/ Center a string to the given length, using the
495+-- specified fill character on either side. Examples:
831496--
832497-- > center 8 'x' "HS" = "xxxHSxxx"
833498center :: Int -> Char -> Text -> Text
@@ -836,7 +501,7 @@ center k c t
836501 | otherwise = replicateChar l c `append` t `append` replicateChar r c
837502 where len = length t
838503 d = k - len
839− r = d `quot` 2
504+ r = d `div` 2
840505 l = d - r
841506{-# INLINE center #-}
842507
@@ -854,12 +519,12 @@ transpose ts = P.map pack (L.transpose (P.map unpack ts))
854519-- (typically the left-identity of the operator), and a 'Text',
855520-- reduces the 'Text' using the binary operator, from left to right.
856521-- Subject to fusion.
857−foldl :: (a -> Char -> a) -> a -> Text -> a
522+foldl :: (b -> Char -> b) -> b -> Text -> b
858523foldl f z t = S.foldl f z (stream t)
859524{-# INLINE foldl #-}
860525
861526-- | /O(n)/ A strict version of 'foldl'. Subject to fusion.
862−foldl' :: (a -> Char -> a) -> a -> Text -> a
527+foldl' :: (b -> Char -> b) -> b -> Text -> b
863528foldl' f z t = S.foldl' f z (stream t)
864529{-# INLINE foldl' #-}
865530
@@ -878,12 +543,12 @@ foldl1' f t = S.foldl1' f (stream t)
878543-- (typically the right-identity of the operator), and a 'Text',
879544-- reduces the 'Text' using the binary operator, from right to left.
880545-- Subject to fusion.
881−foldr :: (Char -> a -> a) -> a -> Text -> a
546+foldr :: (Char -> b -> b) -> b -> Text -> b
882547foldr f z t = S.foldr f z (stream t)
883548{-# INLINE foldr #-}
884549
885550-- | /O(n)/ A variant of 'foldr' that has no starting value argument,
886−-- and thus must be applied to a non-empty 'Text'. Subject to
551+-- and thust must be applied to a non-empty 'Text'. Subject to
887552-- fusion.
888553foldr1 :: (Char -> Char -> Char) -> Text -> Char
889554foldr1 f t = S.foldr1 f (stream t)
@@ -892,36 +557,28 @@ foldr1 f t = S.foldr1 f (stream t)
892557-- -----------------------------------------------------------------------------
893558-- ** Special folds
894559
895−-- | /O(n)/ Concatenate a list of 'Text's.
560+-- | /O(n)/ Concatenate a list of 'Text's. Subject to fusion.
896561concat :: [Text] -> Text
897−concat ts = case ts' of
898− [] -> empty
899− [t] -> t
900− _ -> Text (A.run go) 0 len
901− where
902− ts' = L.filter (not . null) ts
903− len = sumP "concat" $ L.map lengthWord16 ts'
904− go :: ST s (A.MArray s)
905− go = do
906− arr <- A.new len
907− let step i (Text a o l) =
908− let !j = i + l in A.copyI arr i a o j >> return j
909− foldM step 0 ts' >> return arr
562+concat ts = unstream (S.concat (L.map stream ts))
563+{-# INLINE concat #-}
910564
911565-- | /O(n)/ Map a function over a 'Text' that results in a 'Text', and
912−-- concatenate the results.
566+-- concatenate the results. Subject to fusion.
567+--
568+-- Note: if in 'concatMap' @f@ @t@, @f@ is defined in terms of fusible
569+-- functions, it will also be fusible.
913570concatMap :: (Char -> Text) -> Text -> Text
914−concatMap f = concat . foldr ((:) . f) []
571+concatMap f t = unstream (S.concatMap (stream . f) (stream t))
915572{-# INLINE concatMap #-}
916573
917574-- | /O(n)/ 'any' @p@ @t@ determines whether any character in the
918−-- 'Text' @t@ satisfies the predicate @p@. Subject to fusion.
575+-- 'Text' @t@ satisifes the predicate @p@. Subject to fusion.
919576any :: (Char -> Bool) -> Text -> Bool
920577any p t = S.any p (stream t)
921578{-# INLINE any #-}
922579
923580-- | /O(n)/ 'all' @p@ @t@ determines whether all characters in the
924−-- 'Text' @t@ satisfy the predicate @p@. Subject to fusion.
581+-- 'Text' @t@ satisify the predicate @p@. Subject to fusion.
925582all :: (Char -> Bool) -> Text -> Bool
926583all p t = S.all p (stream t)
927584{-# INLINE all #-}
@@ -943,7 +600,6 @@ minimum t = S.minimum (stream t)
943600
944601-- | /O(n)/ 'scanl' is similar to 'foldl', but returns a list of
945602-- successive reduced values from the left. Subject to fusion.
946−-- Performs replacement on invalid scalar values.
947603--
948604-- > scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
949605--
@@ -951,13 +607,11 @@ minimum t = S.minimum (stream t)
951607--
952608-- > last (scanl f z xs) == foldl f z xs.
953609scanl :: (Char -> Char -> Char) -> Char -> Text -> Text
954−scanl f z t = unstream (S.scanl g z (stream t))
955− where g a b = safe (f a b)
610+scanl f z t = unstream (S.scanl f z (stream t))
956611{-# INLINE scanl #-}
957612
958613-- | /O(n)/ 'scanl1' is a variant of 'scanl' that has no starting
959−-- value argument. Subject to fusion. Performs replacement on
960−-- invalid scalar values.
614+-- value argument. Subject to fusion.
961615--
962616-- > scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
963617scanl1 :: (Char -> Char -> Char) -> Text -> Text
@@ -965,63 +619,48 @@ scanl1 f t | null t = empty
965619 | otherwise = scanl f (unsafeHead t) (unsafeTail t)
966620{-# INLINE scanl1 #-}
967621
968−-- | /O(n)/ 'scanr' is the right-to-left dual of 'scanl'. Performs
969−-- replacement on invalid scalar values.
622+-- | /O(n)/ 'scanr' is the right-to-left dual of 'scanl'.
970623--
971624-- > scanr f v == reverse . scanl (flip f) v . reverse
972625scanr :: (Char -> Char -> Char) -> Char -> Text -> Text
973−scanr f z = S.reverse . S.reverseScanr g z . reverseStream
974− where g a b = safe (f a b)
626+scanr f z = S.reverse . S.reverseScanr f z . reverseStream
975627{-# INLINE scanr #-}
976628
977629-- | /O(n)/ 'scanr1' is a variant of 'scanr' that has no starting
978−-- value argument. Subject to fusion. Performs replacement on
979−-- invalid scalar values.
630+-- value argument. Subject to fusion.
980631scanr1 :: (Char -> Char -> Char) -> Text -> Text
981632scanr1 f t | null t = empty
982633 | otherwise = scanr f (last t) (init t)
983634{-# INLINE scanr1 #-}
984635
985−-- | /O(n)/ Like a combination of 'map' and 'foldl''. Applies a
636+-- | /O(n)/ Like a combination of 'map' and 'foldl'. Applies a
986637-- function to each element of a 'Text', passing an accumulating
987−-- parameter from left to right, and returns a final 'Text'. Performs
988−-- replacement on invalid scalar values.
638+-- parameter from left to right, and returns a final 'Text'.
989639mapAccumL :: (a -> Char -> (a,Char)) -> a -> Text -> (a, Text)
990−mapAccumL f z0 = S.mapAccumL g z0 . stream
991− where g a b = second safe (f a b)
992−{-# INLINE mapAccumL #-}
640+mapAccumL f s t = case uncons t of
641+ Nothing -> (s, empty)
642+ Just (x, xs) -> (s'', cons y ys)
643+ where (s', y ) = f s x
644+ (s'',ys) = mapAccumL f s' xs
993645
994646-- | The 'mapAccumR' function behaves like a combination of 'map' and
995−-- a strict 'foldr'; it applies a function to each element of a
996−-- 'Text', passing an accumulating parameter from right to left, and
997−-- returning a final value of this accumulator together with the new
998−-- 'Text'.
999−-- Performs replacement on invalid scalar values.
647+-- 'foldr'; it applies a function to each element of a 'Text', passing
648+-- an accumulating parameter from right to left, and returning a final
649+-- value of this accumulator together with the new 'Text'.
1000650mapAccumR :: (a -> Char -> (a,Char)) -> a -> Text -> (a, Text)
1001−mapAccumR f z0 = second reverse . S.mapAccumL g z0 . reverseStream
1002− where g a b = second safe (f a b)
1003−{-# INLINE mapAccumR #-}
651+mapAccumR f s t = case uncons t of
652+ Nothing -> (s, empty)
653+ Just (x, xs) -> (s'', cons y ys)
654+ where (s'',y ) = f s' x
655+ (s', ys) = mapAccumR f s xs
1004656
1005657-- -----------------------------------------------------------------------------
1006658-- ** Generating and unfolding 'Text's
1007659
1008660-- | /O(n*m)/ 'replicate' @n@ @t@ is a 'Text' consisting of the input
1009−-- @t@ repeated @n@ times.
661+-- @t@ repeated @n@ times. Subject to fusion.
1010662replicate :: Int -> Text -> Text
1011−replicate n t@(Text a o l)
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
1016− where
1017− len = l `mul` n
1018− x :: ST s (A.MArray s)
1019− x = do
1020− arr <- A.new len
1021− let loop !d !i | i >= n = return arr
1022− | otherwise = let m = d + l
1023− in A.copyI arr d a o m >> loop m (i+1)
1024− loop 0 0
663+replicate n t = unstream (S.replicateI (fromIntegral n) (S.stream t))
1025664{-# INLINE [1] replicate #-}
1026665
1027666{-# RULES
@@ -1032,8 +671,7 @@ replicate n t@(Text a o l)
1032671-- | /O(n)/ 'replicateChar' @n@ @c@ is a 'Text' of length @n@ with @c@ the
1033672-- value of every element. Subject to fusion.
1034673replicateChar :: Int -> Char -> Text
1035−replicateChar n c = unstream (S.replicateCharI n (safe c))
1036−{-# INLINE replicateChar #-}
674+replicateChar n c = unstream (S.replicateCharI n c)
1037675
1038676-- | /O(n)/, where @n@ is the length of the result. The 'unfoldr'
1039677-- function is analogous to the List 'L.unfoldr'. 'unfoldr' builds a
@@ -1041,9 +679,9 @@ replicateChar n c = unstream (S.replicateCharI n (safe c))
1041679-- returns 'Nothing' if it is done producing the 'Text', otherwise
1042680-- 'Just' @(a,b)@. In this case, @a@ is the next 'Char' in the
1043681-- string, and @b@ is the seed value for further production. Subject
1044−-- to fusion. Performs replacement on invalid scalar values.
682+-- to fusion.
1045683unfoldr :: (a -> Maybe (Char,a)) -> a -> Text
1046−unfoldr f s = unstream (S.unfoldr (firstf safe . f) s)
684+unfoldr f s = unstream (S.unfoldr f s)
1047685{-# INLINE unfoldr #-}
1048686
1049687-- | /O(n)/ Like 'unfoldr', 'unfoldrN' builds a 'Text' from a seed
@@ -1051,9 +689,9 @@ unfoldr f s = unstream (S.unfoldr (firstf safe . f) s)
1051689-- first argument to 'unfoldrN'. This function is more efficient than
1052690-- 'unfoldr' when the maximum length of the result is known and
1053691-- correct, otherwise its performance is similar to 'unfoldr'. Subject
1054−-- to fusion. Performs replacement on invalid scalar values.
692+-- to fusion.
1055693unfoldrN :: Int -> (a -> Maybe (Char,a)) -> a -> Text
1056−unfoldrN n f s = unstream (S.unfoldrN n (firstf safe . f) s)
694+unfoldrN n f s = unstream (S.unfoldrN n f s)
1057695{-# INLINE unfoldrN #-}
1058696
1059697-- -----------------------------------------------------------------------------
@@ -1066,16 +704,14 @@ take :: Int -> Text -> Text
1066704take n t@(Text arr off len)
1067705 | n <= 0 = empty
1068706 | n >= len = t
1069− | otherwise = text arr off (iterN n t)
707+ | otherwise = Text arr off (loop 0 0)
708+ where
709+ loop !i !cnt
710+ | i >= len || cnt >= n = i
711+ | otherwise = loop (i+d) (cnt+1)
712+ where d = iter_ t i
1070713{-# INLINE [1] take #-}
1071714
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−
1079715{-# RULES
1080716"TEXT take -> fused" [~1] forall n t.
1081717 take n t = unstream (S.take n (stream t))
@@ -1083,36 +719,18 @@ iterN n t@(Text _arr _off len) = loop 0 0
1083719 unstream (S.take n (stream t)) = take n t
1084720 #-}
1085721
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−
1107722-- | /O(n)/ 'drop' @n@, applied to a 'Text', returns the suffix of the
1108−-- 'Text' after the first @n@ characters, or the empty 'Text' if @n@
1109−-- is greater than the length of the 'Text'. Subject to fusion.
723+-- 'Text' of length @n@, or the empty 'Text' if @n@ is greater than the
724+-- length of the 'Text'. Subject to fusion.
1110725drop :: Int -> Text -> Text
1111726drop n t@(Text arr off len)
1112727 | n <= 0 = t
1113728 | n >= len = empty
1114− | otherwise = text arr (off+i) (len-i)
1115− where i = iterN n t
729+ | otherwise = loop 0 0
730+ where loop !i !cnt
731+ | i >= len || cnt >= n = Text arr (off+i) (len-i)
732+ | otherwise = loop (i+d) (cnt+1)
733+ where d = iter_ t i
1116734{-# INLINE [1] drop #-}
1117735
1118736{-# RULES
@@ -1122,18 +740,6 @@ drop n t@(Text arr off len)
1122740 unstream (S.drop n (stream t)) = drop n t
1123741 #-}
1124742
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−
1137743-- | /O(n)/ 'takeWhile', applied to a predicate @p@ and a 'Text',
1138744-- returns the longest prefix (possibly empty) of elements that
1139745-- satisfy @p@. Subject to fusion.
@@ -1141,8 +747,8 @@ takeWhile :: (Char -> Bool) -> Text -> Text
1141747takeWhile p t@(Text arr off len) = loop 0
1142748 where loop !i | i >= len = t
1143749 | p c = loop (i+d)
1144− | otherwise = text arr off i
1145− where Iter c d = iter t i
750+ | otherwise = textP arr off i
751+ where (c,d) = iter t i
1146752{-# INLINE [1] takeWhile #-}
1147753
1148754{-# RULES
@@ -1152,27 +758,6 @@ takeWhile p t@(Text arr off len) = loop 0
1152758 unstream (S.takeWhile p (stream t)) = takeWhile p t
1153759 #-}
1154760
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−
1176761-- | /O(n)/ 'dropWhile' @p@ @t@ returns the suffix remaining after
1177762-- 'takeWhile' @p@ @t@. Subject to fusion.
1178763dropWhile :: (Char -> Bool) -> Text -> Text
@@ -1180,7 +765,7 @@ dropWhile p t@(Text arr off len) = loop 0 0
1180765 where loop !i !l | l >= len = empty
1181766 | p c = loop (i+d) (l+d)
1182767 | otherwise = Text arr (off+i) (len-l)
1183− where Iter c d = iter t i
768+ where (c,d) = iter t i
1184769{-# INLINE [1] dropWhile #-}
1185770
1186771{-# RULES
@@ -1191,9 +776,8 @@ dropWhile p t@(Text arr off len) = loop 0 0
1191776 #-}
1192777
1193778-- | /O(n)/ 'dropWhileEnd' @p@ @t@ returns the prefix remaining after
1194−-- dropping characters that satisfy the predicate @p@ from the end of
779+-- dropping characters that fail the predicate @p@ from the end of
1195780-- @t@. Subject to fusion.
1196−--
1197781-- Examples:
1198782--
1199783-- > dropWhileEnd (=='.') "foo..." == "foo"
@@ -1213,7 +797,7 @@ dropWhileEnd p t@(Text arr off len) = loop (len-1) len
1213797 #-}
1214798
1215799-- | /O(n)/ 'dropAround' @p@ @t@ returns the substring remaining after
1216−-- dropping characters that satisfy the predicate @p@ from both the
800+-- dropping characters that fail the predicate @p@ from both the
1217801-- beginning and end of @t@. Subject to fusion.
1218802dropAround :: (Char -> Bool) -> Text -> Text
1219803dropAround p = dropWhile p . dropWhileEnd p
@@ -1248,23 +832,31 @@ splitAt :: Int -> Text -> (Text, Text)
1248832splitAt n t@(Text arr off len)
1249833 | n <= 0 = (empty, t)
1250834 | n >= len = (t, empty)
1251− | otherwise = let k = iterN n t
1252− in (text arr off k, text arr (off+k) (len-k))
835+ | otherwise = (Text arr off k, Text arr (off+k) (len-k))
836+ where k = loop 0 0
837+ loop !i !cnt
838+ | i >= len || cnt >= n = i
839+ | otherwise = loop (i+d) (cnt+1)
840+ where d = iter_ t i
841+{-# INLINE splitAt #-}
1253842
1254−-- | /O(n)/ 'span', applied to a predicate @p@ and text @t@, returns
843+-- | /O(n)/ 'spanBy', applied to a predicate @p@ and text @t@, returns
1255844-- a pair whose first element is the longest prefix (possibly empty)
1256845-- of @t@ of elements that satisfy @p@, and whose second is the
1257846-- remainder of the list.
1258−span :: (Char -> Bool) -> Text -> (Text, Text)
1259−span p t = case span_ p t of
1260− (# hd,tl #) -> (hd,tl)
1261−{-# INLINE span #-}
1262−
1263−-- | /O(n)/ 'break' is like 'span', but the prefix returned is
847+spanBy :: (Char -> Bool) -> Text -> (Text, Text)
848+spanBy p t@(Text arr off len) = (textP arr off k, textP arr (off+k) (len-k))
849+ where k = loop 0
850+ loop !i | i >= len || not (p c) = i
851+ | otherwise = loop (i+d)
852+ where (c,d) = iter t i
853+{-# INLINE spanBy #-}
854+
855+-- | /O(n)/ 'breakBy' is like 'spanBy', but the prefix returned is
1264856-- over elements that fail the predicate @p@.
1265−break :: (Char -> Bool) -> Text -> (Text, Text)
1266−break p = span (not . p)
1267−{-# INLINE break #-}
857+breakBy :: (Char -> Bool) -> Text -> (Text, Text)
858+breakBy p = spanBy (not . p)
859+{-# INLINE breakBy #-}
1268860
1269861-- | /O(n)/ Group characters in a string according to a predicate.
1270862groupBy :: (Char -> Char -> Bool) -> Text -> [Text]
@@ -1273,7 +865,7 @@ groupBy p = loop
1273865 loop t@(Text arr off len)
1274866 | null t = []
1275867 | otherwise = text arr off n : loop (text arr (off+n) (len-n))
1276− where Iter c d = iter t 0
868+ where (c,d) = iter t 0
1277869 n = d + findAIndexOrEnd (not . p c) (Text arr (off+d) (len-d))
1278870
1279871-- | Returns the /array/ index (in units of 'Word16') at which a
@@ -1283,8 +875,8 @@ findAIndexOrEnd :: (Char -> Bool) -> Text -> Int
1283875findAIndexOrEnd q t@(Text _arr _off len) = go 0
1284876 where go !i | i >= len || q c = i
1285877 | otherwise = go (i+d)
1286− where Iter c d = iter t i
1287−
878+ where (c,d) = iter t i
879+
1288880-- | /O(n)/ Group characters in a string by equality.
1289881group :: Text -> [Text]
1290882group = groupBy (==)
@@ -1308,43 +900,36 @@ tails t | null t = [empty]
1308900-- copies to create substrings; they just construct new 'Text's that
1309901-- are slices of the original.
1310902
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.
903+-- | /O(m+n)/ Break a 'Text' into pieces separated by the first
904+-- 'Text' argument, consuming the delimiter. An empty delimiter is
905+-- invalid, and will cause an error to be raised.
1314906--
1315907-- Examples:
1316908--
1317−-- > splitOn "\r\n" "a\r\nb\r\nd\r\ne" == ["a","b","d","e"]
1318−-- > splitOn "aaa" "aaaXaaaXaaaXaaa" == ["","X","X","X",""]
1319−-- > splitOn "x" "x" == ["",""]
1320−--
909+-- > split "\r\n" "a\r\nb\r\nd\r\ne" == ["a","b","d","e"]
910+-- > split "aaa" "aaaXaaaXaaaXaaa" == ["","X","X","X",""]
911+-- > split "x" "x" == ["",""]
912+--
1321913-- and
1322914--
1323−-- > intercalate s . splitOn s == id
1324−-- > splitOn (singleton c) == split (==c)
1325−--
1326−-- (Note: the string @s@ to split on above cannot be empty.)
915+-- > intercalate s . split s == id
916+-- > split (singleton c) == splitBy (==c)
1327917--
1328918-- In (unlikely) bad cases, this function's time complexity degrades
1329919-- towards /O(n*m)/.
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]
1336−splitOn pat@(Text _ _ l) src@(Text arr off len)
1337− | l <= 0 = emptyError "splitOn"
1338− | isSingleton pat = split (== unsafeHead pat) src
920+split :: Text -> Text -> [Text]
921+split pat@(Text _ _ l) src@(Text arr off len)
922+ | l <= 0 = emptyError "split"
923+ | isSingleton pat = splitBy (== unsafeHead pat) src
1339924 | otherwise = go 0 (indices pat src)
1340925 where
1341− go !s (x:xs) = text arr (s+off) (x-s) : go (x+l) xs
1342− go s _ = [text arr (s+off) (len-s)]
1343−{-# INLINE [1] splitOn #-}
926+ go !s (x:xs) = textP arr (s+off) (x-s) : go (x+l) xs
927+ go s _ = [textP arr (s+off) (len-s)]
928+{-# INLINE [1] split #-}
1344929
1345930{-# RULES
1346−"TEXT splitOn/singleton -> split/==" [~1] forall c t.
1347− splitOn (singleton c) t = split (==c) t
931+"TEXT split/singleton -> splitBy/==" [~1] forall c t.
932+ split (singleton c) t = splitBy (==c) t
1348933 #-}
1349934
1350935-- | /O(n)/ Splits a 'Text' into components delimited by separators,
@@ -1352,15 +937,15 @@ splitOn pat@(Text _ _ l) src@(Text arr off len)
1352937-- resulting components do not contain the separators. Two adjacent
1353938-- separators result in an empty component in the output. eg.
1354939--
1355−-- > split (=='a') "aabbaca" == ["","","bb","c",""]
1356−-- > split (=='a') "" == [""]
1357−split :: (Char -> Bool) -> Text -> [Text]
1358−split _ t@(Text _off _arr 0) = [t]
1359−split p t = loop t
940+-- > splitBy (=='a') "aabbaca" == ["","","bb","c",""]
941+-- > splitBy (=='a') "" == [""]
942+splitBy :: (Char -> Bool) -> Text -> [Text]
943+splitBy _ t@(Text _off _arr 0) = [t]
944+splitBy p t = loop t
1360945 where loop s | null s' = [l]
1361946 | otherwise = l : loop (unsafeTail s')
1362− where (# l, s' #) = span_ (not . p) s
1363−{-# INLINE split #-}
947+ where (l, s') = breakBy p s
948+{-# INLINE splitBy #-}
1364949
1365950-- | /O(n)/ Splits a 'Text' into components of length @k@. The last
1366951-- element may be shorter than the other chunks, depending on the
@@ -1379,24 +964,32 @@ chunksOf k = go
1379964-- ----------------------------------------------------------------------------
1380965-- * Searching
1381966
967+-------------------------------------------------------------------------------
968+-- ** Searching by equality
969+
970+-- | /O(n)/ 'elem' is the 'Text' membership predicate.
971+elem :: Char -> Text -> Bool
972+elem c t = S.elem c (stream t)
973+{-# INLINE elem #-}
974+
1382975-------------------------------------------------------------------------------
1383976-- ** Searching with a predicate
1384977
1385−-- | /O(n)/ The 'find' function takes a predicate and a 'Text', and
1386−-- returns the first element matching the predicate, or 'Nothing' if
1387−-- there is no such element.
1388−find :: (Char -> Bool) -> Text -> Maybe Char
1389−find p t = S.findBy p (stream t)
1390−{-# INLINE find #-}
978+-- | /O(n)/ The 'findBy' function takes a predicate and a 'Text', and
979+-- returns the first element in matching the predicate, or 'Nothing'
980+-- if there is no such element.
981+findBy :: (Char -> Bool) -> Text -> Maybe Char
982+findBy p t = S.findBy p (stream t)
983+{-# INLINE findBy #-}
1391984
1392−-- | /O(n)/ The 'partition' function takes a predicate and a 'Text',
985+-- | /O(n)/ The 'partitionBy' function takes a predicate and a 'Text',
1393986-- and returns the pair of 'Text's with elements which do and do not
1394987-- satisfy the predicate, respectively; i.e.
1395988--
1396−-- > partition p t == (filter p t, filter (not . p) t)
1397−partition :: (Char -> Bool) -> Text -> (Text, Text)
1398−partition p t = (filter p t, filter (not . p) t)
1399−{-# INLINE partition #-}
989+-- > partitionBy p t == (filter p t, filter (not . p) t)
990+partitionBy :: (Char -> Bool) -> Text -> (Text, Text)
991+partitionBy p t = (filter p t, filter (not . p) t)
992+{-# INLINE partitionBy #-}
1400993
1401994-- | /O(n)/ 'filter', applied to a predicate and a 'Text',
1402995-- returns a 'Text' containing those characters that satisfy the
@@ -1412,69 +1005,56 @@ filter p t = unstream (S.filter p (stream t))
14121005--
14131006-- Examples:
14141007--
1415−-- > breakOn "::" "a::b::c" ==> ("a", "::b::c")
1416−-- > breakOn "/" "foobar" ==> ("foobar", "")
1008+-- > break "::" "a::b::c" ==> ("a", "::b::c")
1009+-- > break "/" "foobar" ==> ("foobar", "")
14171010--
14181011-- Laws:
14191012--
14201013-- > append prefix match == haystack
1421−-- > where (prefix, match) = breakOn needle haystack
1014+-- > where (prefix, match) = break needle haystack
14221015--
14231016-- If you need to break a string by a substring repeatedly (e.g. you
1424−-- want to break on every instance of a substring), use 'breakOnAll'
1017+-- want to break on every instance of a substring), use 'find'
14251018-- instead, as it has lower startup overhead.
14261019--
14271020-- In (unlikely) bad cases, this function's time complexity degrades
14281021-- towards /O(n*m)/.
1429−breakOn :: Text -> Text -> (Text, Text)
1430−breakOn pat src@(Text arr off len)
1431− | null pat = emptyError "breakOn"
1022+break :: Text -> Text -> (Text, Text)
1023+break pat src@(Text arr off len)
1024+ | null pat = emptyError "break"
14321025 | otherwise = case indices pat src of
14331026 [] -> (src, empty)
1434− (x:_) -> (text arr off x, text arr (off+x) (len-x))
1435−{-# INLINE breakOn #-}
1436−
1437−-- | /O(n+m)/ Similar to 'breakOn', but searches from the end of the
1438−-- string.
1439−--
1440−-- The first element of the returned tuple is the prefix of @haystack@
1441−-- up to and including the last match of @needle@. The second is the
1442−-- remainder of @haystack@, following the match.
1443−--
1444−-- > breakOnEnd "::" "a::b::c" ==> ("a::b::", "c")
1445−breakOnEnd :: Text -> Text -> (Text, Text)
1446−breakOnEnd pat src = (reverse b, reverse a)
1447− where (a,b) = breakOn (reverse pat) (reverse src)
1448−{-# INLINE breakOnEnd #-}
1027+ (x:_) -> (textP arr off x, textP arr (off+x) (len-x))
1028+{-# INLINE break #-}
14491029
14501030-- | /O(n+m)/ Find all non-overlapping instances of @needle@ in
1451−-- @haystack@. Each element of the returned list consists of a pair:
1452−--
1453−-- * The entire string prior to the /k/th match (i.e. the prefix)
1031+-- @haystack@. The first element of the returned pair is the prefix
1032+-- of @haystack@ prior to any matches of @needle@. The second is a
1033+-- list of pairs.
14541034--
1455−-- * The /k/th match, followed by the remainder of the string
1035+-- The first element of each pair in the list is a span from the
1036+-- beginning of a match to the beginning of the next match, while the
1037+-- second is a span from the beginning of the match to the end of the
1038+-- input.
14561039--
14571040-- Examples:
14581041--
1459−-- > breakOnAll "::" ""
1460−-- > ==> []
1461−-- > breakOnAll "/" "a/b/c/"
1462−-- > ==> [("a", "/b/c/"), ("a/b", "/c/"), ("a/b/c", "/")]
1463−--
1464−-- In (unlikely) bad cases, this function's time complexity degrades
1465−-- towards /O(n*m)/.
1466−--
1467−-- The @needle@ parameter may not be empty.
1468−breakOnAll :: Text -- ^ @needle@ to search for
1469− -> Text -- ^ @haystack@ in which to search
1470− -> [(Text, Text)]
1471−breakOnAll pat src@(Text arr off slen)
1472− | null pat = emptyError "breakOnAll"
1473− | otherwise = L.map step (indices pat src)
1042+-- > find "::" ""
1043+-- > ==> ("", [])
1044+-- > find "/" "a/b/c/d"
1045+-- > ==> ("a", [("/b","/b/c/d"), ("/c","/c/d"), ("/d","/d")])
1046+find :: Text -> Text -> (Text, [(Text, Text)])
1047+find pat src@(Text arr off len)
1048+ | null pat = emptyError "find"
1049+ | otherwise = case indices pat src of
1050+ [] -> (src, [])
1051+ (x:xs) -> (chunk 0 x, go x xs)
14741052 where
1475− step x = (chunk 0 x, chunk x (slen-x))
1476− chunk !n !l = text arr (n+off) l
1477−{-# INLINE breakOnAll #-}
1053+ go !s (x:xs) = (chunk s (x-s), chunk s (len-s)) : go x xs
1054+ go s _ = let c = chunk s (len-s)
1055+ in [(c,c)]
1056+ chunk !n !l = textP arr (n+off) l
1057+{-# INLINE find #-}
14781058
14791059-------------------------------------------------------------------------------
14801060-- ** Indexing 'Text's
@@ -1493,7 +1073,7 @@ breakOnAll pat src@(Text arr off slen)
14931073-- For example, suppose you have a string that you want to split on
14941074-- the substring @\"::\"@, such as @\"foo::bar::quux\"@. Instead of
14951075-- searching for the index of @\"::\"@ and taking the substrings
1496−-- before and after that index, you would instead use @breakOnAll \"::\"@.
1076+-- before and after that index, you would instead use @find "::"@.
14971077
14981078-- | /O(n)/ 'Text' index (subscript) operator, starting from 0.
14991079index :: Text -> Int -> Char
@@ -1540,15 +1120,13 @@ countChar c t = S.countChar c (stream t)
15401120-- equivalent to a pair of 'unpack' operations.
15411121zip :: Text -> Text -> [(Char,Char)]
15421122zip a b = S.unstreamList $ S.zipWith (,) (stream a) (stream b)
1543−{-# INLINE zip #-}
1123+{-# INLINE [0] zip #-}
15441124
15451125-- | /O(n)/ 'zipWith' generalises 'zip' by zipping with the function
15461126-- given as the first argument, instead of a tupling function.
1547−-- Performs replacement on invalid scalar values.
15481127zipWith :: (Char -> Char -> Char) -> Text -> Text -> Text
1549−zipWith f t1 t2 = unstream (S.zipWith g (stream t1) (stream t2))
1550− where g a b = safe (f a b)
1551−{-# INLINE zipWith #-}
1128+zipWith f t1 t2 = unstream (S.zipWith f (stream t1) (stream t2))
1129+{-# INLINE [0] zipWith #-}
15521130
15531131-- | /O(n)/ Breaks a 'Text' up into a list of words, delimited by 'Char's
15541132-- representing white space.
@@ -1564,7 +1142,7 @@ words t@(Text arr off len) = loop 0 0
15641142 then loop (start+1) (start+1)
15651143 else Text arr (start+off) (n-start) : loop (n+d) (n+d)
15661144 | otherwise = loop start (n+d)
1567− where Iter c d = iter t n
1145+ where (c,d) = iter t n
15681146{-# INLINE words #-}
15691147
15701148-- | /O(n)/ Breaks a 'Text' up into a list of 'Text's at
@@ -1574,10 +1152,9 @@ lines ps | null ps = []
15741152 | otherwise = h : if null t
15751153 then []
15761154 else lines (unsafeTail t)
1577− where (# h,t #) = span_ (/= '\n') ps
1155+ where (h,t) = spanBy (/= '\n') ps
15781156{-# INLINE lines #-}
15791157
1580−{-
15811158-- | /O(n)/ Portably breaks a 'Text' up into a list of 'Text's at line
15821159-- boundaries.
15831160--
@@ -1585,6 +1162,7 @@ lines ps | null ps = []
15851162-- return immediately followed by a line feed, or a carriage return.
15861163-- This accounts for both Unix and Windows line ending conventions,
15871164-- and for the old convention used on Mac OS 9 and earlier.
1165+{-
15881166lines' :: Text -> [Text]
15891167lines' ps | null ps = []
15901168 | otherwise = h : case uncons t of
@@ -1611,7 +1189,8 @@ unwords = intercalate (singleton ' ')
16111189{-# INLINE unwords #-}
16121190
16131191-- | /O(n)/ The 'isPrefixOf' function takes two 'Text's and returns
1614−-- 'True' iff the first is a prefix of the second. Subject to fusion.
1192+-- 'True' iff the first is a prefix of the second. This function is
1193+-- subject to fusion.
16151194isPrefixOf :: Text -> Text -> Bool
16161195isPrefixOf a@(Text _ _ alen) b@(Text _ _ blen) =
16171196 alen <= blen && S.isPrefixOf (stream a) (stream b)
@@ -1620,6 +1199,8 @@ isPrefixOf a@(Text _ _ alen) b@(Text _ _ blen) =
16201199{-# RULES
16211200"TEXT isPrefixOf -> fused" [~1] forall s t.
16221201 isPrefixOf s t = S.isPrefixOf (stream s) (stream t)
1202+"TEXT isPrefixOf -> unfused" [1] forall s t.
1203+ S.isPrefixOf (stream s) (stream t) = isPrefixOf s t
16231204 #-}
16241205
16251206-- | /O(n)/ The 'isSuffixOf' function takes two 'Text's and returns
@@ -1639,117 +1220,8 @@ isSuffixOf a@(Text _aarr _aoff alen) b@(Text barr boff blen) =
16391220-- In (unlikely) bad cases, this function's time complexity degrades
16401221-- towards /O(n*m)/.
16411222isInfixOf :: Text -> Text -> Bool
1642−isInfixOf needle haystack
1643− | null needle = True
1644− | isSingleton needle = S.elem (unsafeHead needle) . S.stream $ haystack
1645− | otherwise = not . L.null . indices needle $ haystack
1646−{-# INLINE [1] isInfixOf #-}
1647−
1648−{-# RULES
1649−"TEXT isInfixOf/singleton -> S.elem/S.stream" [~1] forall n h.
1650− isInfixOf (singleton n) h = S.elem n (S.stream h)
1651− #-}
1652−
1653−-------------------------------------------------------------------------------
1654−-- * View patterns
1655−
1656−-- | /O(n)/ Return the suffix of the second string if its prefix
1657−-- matches the entire first string.
1658−--
1659−-- Examples:
1660−--
1661−-- > stripPrefix "foo" "foobar" == Just "bar"
1662−-- > stripPrefix "" "baz" == Just "baz"
1663−-- > stripPrefix "foo" "quux" == Nothing
1664−--
1665−-- This is particularly useful with the @ViewPatterns@ extension to
1666−-- GHC, as follows:
1667−--
1668−-- > {-# LANGUAGE ViewPatterns #-}
1669−-- > import Data.Text as T
1670−-- >
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
1678−
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
1681−-- no longer match.
1682−--
1683−-- If the strings do not have a common prefix or either one is empty,
1684−-- this function returns 'Nothing'.
1685−--
1686−-- Examples:
1687−--
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
1693− where
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
1701−
1702−-- | /O(n)/ Return the prefix of the second string if its suffix
1703−-- matches the entire first string.
1704−--
1705−-- Examples:
1706−--
1707−-- > stripSuffix "bar" "foobar" == Just "foo"
1708−-- > stripSuffix "" "baz" == Just "baz"
1709−-- > stripSuffix "foo" "quux" == Nothing
1710−--
1711−-- This is particularly useful with the @ViewPatterns@ extension to
1712−-- GHC, as follows:
1713−--
1714−-- > {-# LANGUAGE ViewPatterns #-}
1715−-- > import Data.Text as T
1716−-- >
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
1724−
1725−-- | Add a list of non-negative numbers. Errors out on overflow.
1726−sumP :: String -> [Int] -> Int
1727−sumP fun = go 0
1728− where go !a (x:xs)
1729− | ax >= 0 = go ax xs
1730− | otherwise = overflowError fun
1731− where ax = a + x
1732− go a _ = a
1223+isInfixOf pat src = null pat || (not . L.null $ indices pat src)
1224+{-# INLINE isInfixOf #-}
17331225
17341226emptyError :: String -> a
1735−emptyError fun = P.error $ "Data.Text." ++ fun ++ ": empty input"
1736−
1737−overflowError :: String -> a
1738−overflowError 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
1227+emptyError fun = P.error ("Data.Text." ++ fun ++ ": empty input")