2 -----------------------------------------------------------------------------
4 -- Module : Data.Sequence
5 -- Copyright : (c) Ross Paterson 2005
7 -- Maintainer : ross@soi.city.ac.uk
8 -- Stability : experimental
9 -- Portability : portable
11 -- General purpose finite sequences.
12 -- Apart from being finite and having strict operations, sequences
13 -- also differ from lists in supporting a wider variety of operations
16 -- An amortized running time is given for each operation, with /n/ referring
17 -- to the length of the sequence and /i/ being the integral index used by
18 -- some operations. These bounds hold even in a persistent (shared) setting.
20 -- The implementation uses 2-3 finger trees annotated with sizes,
21 -- as described in section 4.2 of
23 -- * Ralf Hinze and Ross Paterson,
24 -- \"Finger trees: a simple general-purpose data structure\",
25 -- submitted to /Journal of Functional Programming/.
26 -- <http://www.soi.city.ac.uk/~ross/papers/FingerTree.html>
28 -- /Note/: Many of these operations have the same names as similar
29 -- operations on lists in the "Prelude". The ambiguity may be resolved
30 -- using either qualification or the @hiding@ clause.
32 -----------------------------------------------------------------------------
34 module Data.Sequence (
38 singleton, -- :: a -> Seq a
39 (<|), -- :: a -> Seq a -> Seq a
40 (|>), -- :: Seq a -> a -> Seq a
41 (><), -- :: Seq a -> Seq a -> Seq a
44 null, -- :: Seq a -> Bool
45 length, -- :: Seq a -> Int
48 viewl, -- :: Seq a -> ViewL a
50 viewr, -- :: Seq a -> ViewR a
52 index, -- :: Seq a -> Int -> a
53 adjust, -- :: (a -> a) -> Int -> Seq a -> Seq a
54 update, -- :: Int -> a -> Seq a -> Seq a
55 take, -- :: Int -> Seq a -> Seq a
56 drop, -- :: Int -> Seq a -> Seq a
57 splitAt, -- :: Int -> Seq a -> (Seq a, Seq a)
59 fromList, -- :: [a] -> Seq a
60 toList, -- :: Seq a -> [a]
62 -- ** Right associative
63 foldr, -- :: (a -> b -> b) -> b -> Seq a -> b
64 foldr1, -- :: (a -> a -> a) -> Seq a -> a
65 foldr', -- :: (a -> b -> b) -> b -> Seq a -> b
66 foldrM, -- :: Monad m => (a -> b -> m b) -> b -> Seq a -> m b
67 -- ** Left associative
68 foldl, -- :: (a -> b -> a) -> a -> Seq b -> a
69 foldl1, -- :: (a -> a -> a) -> Seq a -> a
70 foldl', -- :: (a -> b -> a) -> a -> Seq b -> a
71 foldlM, -- :: Monad m => (a -> b -> m a) -> a -> Seq b -> m a
73 reverse, -- :: Seq a -> Seq a
79 import Prelude hiding (
80 null, length, take, drop, splitAt, foldl, foldl1, foldr, foldr1,
82 import qualified Prelude (foldr)
83 import qualified Data.List (foldl', intersperse)
88 import Control.Monad (liftM, liftM2, liftM3, liftM4)
89 import Test.QuickCheck
92 #if __GLASGOW_HASKELL__
93 import Data.Generics.Basics (Data(..), mkNorepType)
106 ------------------------------------------------------------------------
107 -- Random access sequences
108 ------------------------------------------------------------------------
110 -- | General-purpose finite sequences.
111 newtype Seq a = Seq (FingerTree (Elem a))
113 instance Functor Seq where
114 fmap f (Seq xs) = Seq (fmap (fmap f) xs)
116 instance Eq a => Eq (Seq a) where
117 xs == ys = length xs == length ys && toList xs == toList ys
119 instance Ord a => Ord (Seq a) where
120 compare xs ys = compare (toList xs) (toList ys)
123 instance (Show a) => Show (Seq a) where
124 showsPrec p (Seq x) = showsPrec p x
126 instance Show a => Show (Seq a) where
127 showsPrec _ xs = showChar '<' .
128 flip (Prelude.foldr ($)) (Data.List.intersperse (showChar ',')
129 (map shows (toList xs))) .
133 instance FunctorM Seq where
134 fmapM f = foldlM f' empty
138 fmapM_ f = foldlM f' ()
139 where f' _ x = f x >> return ()
141 #include "Typeable.h"
142 INSTANCE_TYPEABLE1(Seq,seqTc,"Seq")
144 #if __GLASGOW_HASKELL__
145 instance Data a => Data (Seq a) where
146 gfoldl f z xs = z fromList `f` toList xs
147 toConstr _ = error "toConstr"
148 gunfold _ _ = error "gunfold"
149 dataTypeOf _ = mkNorepType "Data.Sequence.Seq"
157 | Deep {-# UNPACK #-} !Int !(Digit a) (FingerTree (Node a)) !(Digit a)
162 instance Sized a => Sized (FingerTree a) where
164 size (Single x) = size x
165 size (Deep v _ _ _) = v
167 instance Functor FingerTree where
169 fmap f (Single x) = Single (f x)
170 fmap f (Deep v pr m sf) =
171 Deep v (fmap f pr) (fmap (fmap f) m) (fmap f sf)
174 deep :: Sized a => Digit a -> FingerTree (Node a) -> Digit a -> FingerTree a
175 deep pr m sf = Deep (size pr + size m + size sf) pr m sf
188 instance Functor Digit where
189 fmap f (One a) = One (f a)
190 fmap f (Two a b) = Two (f a) (f b)
191 fmap f (Three a b c) = Three (f a) (f b) (f c)
192 fmap f (Four a b c d) = Four (f a) (f b) (f c) (f d)
194 instance Sized a => Sized (Digit a) where
195 size xs = foldlDigit (\ i x -> i + size x) 0 xs
197 {-# SPECIALIZE digitToTree :: Digit (Elem a) -> FingerTree (Elem a) #-}
198 {-# SPECIALIZE digitToTree :: Digit (Node a) -> FingerTree (Node a) #-}
199 digitToTree :: Sized a => Digit a -> FingerTree a
200 digitToTree (One a) = Single a
201 digitToTree (Two a b) = deep (One a) Empty (One b)
202 digitToTree (Three a b c) = deep (Two a b) Empty (One c)
203 digitToTree (Four a b c d) = deep (Two a b) Empty (Two c d)
208 = Node2 {-# UNPACK #-} !Int a a
209 | Node3 {-# UNPACK #-} !Int a a a
214 instance Functor (Node) where
215 fmap f (Node2 v a b) = Node2 v (f a) (f b)
216 fmap f (Node3 v a b c) = Node3 v (f a) (f b) (f c)
218 instance Sized (Node a) where
219 size (Node2 v _ _) = v
220 size (Node3 v _ _ _) = v
223 node2 :: Sized a => a -> a -> Node a
224 node2 a b = Node2 (size a + size b) a b
227 node3 :: Sized a => a -> a -> a -> Node a
228 node3 a b c = Node3 (size a + size b + size c) a b c
230 nodeToDigit :: Node a -> Digit a
231 nodeToDigit (Node2 _ a b) = Two a b
232 nodeToDigit (Node3 _ a b c) = Three a b c
236 newtype Elem a = Elem { getElem :: a }
238 instance Sized (Elem a) where
241 instance Functor Elem where
242 fmap f (Elem x) = Elem (f x)
245 instance (Show a) => Show (Elem a) where
246 showsPrec p (Elem x) = showsPrec p x
249 ------------------------------------------------------------------------
251 ------------------------------------------------------------------------
253 -- | /O(1)/. The empty sequence.
257 -- | /O(1)/. A singleton sequence.
258 singleton :: a -> Seq a
259 singleton x = Seq (Single (Elem x))
261 -- | /O(1)/. Add an element to the left end of a sequence.
262 -- Mnemonic: a triangle with the single element at the pointy end.
263 (<|) :: a -> Seq a -> Seq a
264 x <| Seq xs = Seq (Elem x `consTree` xs)
266 {-# SPECIALIZE consTree :: Elem a -> FingerTree (Elem a) -> FingerTree (Elem a) #-}
267 {-# SPECIALIZE consTree :: Node a -> FingerTree (Node a) -> FingerTree (Node a) #-}
268 consTree :: Sized a => a -> FingerTree a -> FingerTree a
269 consTree a Empty = Single a
270 consTree a (Single b) = deep (One a) Empty (One b)
271 consTree a (Deep s (Four b c d e) m sf) = m `seq`
272 Deep (size a + s) (Two a b) (node3 c d e `consTree` m) sf
273 consTree a (Deep s (Three b c d) m sf) =
274 Deep (size a + s) (Four a b c d) m sf
275 consTree a (Deep s (Two b c) m sf) =
276 Deep (size a + s) (Three a b c) m sf
277 consTree a (Deep s (One b) m sf) =
278 Deep (size a + s) (Two a b) m sf
280 -- | /O(1)/. Add an element to the right end of a sequence.
281 -- Mnemonic: a triangle with the single element at the pointy end.
282 (|>) :: Seq a -> a -> Seq a
283 Seq xs |> x = Seq (xs `snocTree` Elem x)
285 {-# SPECIALIZE snocTree :: FingerTree (Elem a) -> Elem a -> FingerTree (Elem a) #-}
286 {-# SPECIALIZE snocTree :: FingerTree (Node a) -> Node a -> FingerTree (Node a) #-}
287 snocTree :: Sized a => FingerTree a -> a -> FingerTree a
288 snocTree Empty a = Single a
289 snocTree (Single a) b = deep (One a) Empty (One b)
290 snocTree (Deep s pr m (Four a b c d)) e = m `seq`
291 Deep (s + size e) pr (m `snocTree` node3 a b c) (Two d e)
292 snocTree (Deep s pr m (Three a b c)) d =
293 Deep (s + size d) pr m (Four a b c d)
294 snocTree (Deep s pr m (Two a b)) c =
295 Deep (s + size c) pr m (Three a b c)
296 snocTree (Deep s pr m (One a)) b =
297 Deep (s + size b) pr m (Two a b)
299 -- | /O(log(min(n1,n2)))/. Concatenate two sequences.
300 (><) :: Seq a -> Seq a -> Seq a
301 Seq xs >< Seq ys = Seq (appendTree0 xs ys)
303 -- The appendTree/addDigits gunk below is machine generated
305 appendTree0 :: FingerTree (Elem a) -> FingerTree (Elem a) -> FingerTree (Elem a)
306 appendTree0 Empty xs =
308 appendTree0 xs Empty =
310 appendTree0 (Single x) xs =
312 appendTree0 xs (Single x) =
314 appendTree0 (Deep s1 pr1 m1 sf1) (Deep s2 pr2 m2 sf2) =
315 Deep (s1 + s2) pr1 (addDigits0 m1 sf1 pr2 m2) sf2
317 addDigits0 :: FingerTree (Node (Elem a)) -> Digit (Elem a) -> Digit (Elem a) -> FingerTree (Node (Elem a)) -> FingerTree (Node (Elem a))
318 addDigits0 m1 (One a) (One b) m2 =
319 appendTree1 m1 (node2 a b) m2
320 addDigits0 m1 (One a) (Two b c) m2 =
321 appendTree1 m1 (node3 a b c) m2
322 addDigits0 m1 (One a) (Three b c d) m2 =
323 appendTree2 m1 (node2 a b) (node2 c d) m2
324 addDigits0 m1 (One a) (Four b c d e) m2 =
325 appendTree2 m1 (node3 a b c) (node2 d e) m2
326 addDigits0 m1 (Two a b) (One c) m2 =
327 appendTree1 m1 (node3 a b c) m2
328 addDigits0 m1 (Two a b) (Two c d) m2 =
329 appendTree2 m1 (node2 a b) (node2 c d) m2
330 addDigits0 m1 (Two a b) (Three c d e) m2 =
331 appendTree2 m1 (node3 a b c) (node2 d e) m2
332 addDigits0 m1 (Two a b) (Four c d e f) m2 =
333 appendTree2 m1 (node3 a b c) (node3 d e f) m2
334 addDigits0 m1 (Three a b c) (One d) m2 =
335 appendTree2 m1 (node2 a b) (node2 c d) m2
336 addDigits0 m1 (Three a b c) (Two d e) m2 =
337 appendTree2 m1 (node3 a b c) (node2 d e) m2
338 addDigits0 m1 (Three a b c) (Three d e f) m2 =
339 appendTree2 m1 (node3 a b c) (node3 d e f) m2
340 addDigits0 m1 (Three a b c) (Four d e f g) m2 =
341 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
342 addDigits0 m1 (Four a b c d) (One e) m2 =
343 appendTree2 m1 (node3 a b c) (node2 d e) m2
344 addDigits0 m1 (Four a b c d) (Two e f) m2 =
345 appendTree2 m1 (node3 a b c) (node3 d e f) m2
346 addDigits0 m1 (Four a b c d) (Three e f g) m2 =
347 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
348 addDigits0 m1 (Four a b c d) (Four e f g h) m2 =
349 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
351 appendTree1 :: FingerTree (Node a) -> Node a -> FingerTree (Node a) -> FingerTree (Node a)
352 appendTree1 Empty a xs =
354 appendTree1 xs a Empty =
356 appendTree1 (Single x) a xs =
357 x `consTree` a `consTree` xs
358 appendTree1 xs a (Single x) =
359 xs `snocTree` a `snocTree` x
360 appendTree1 (Deep s1 pr1 m1 sf1) a (Deep s2 pr2 m2 sf2) =
361 Deep (s1 + size a + s2) pr1 (addDigits1 m1 sf1 a pr2 m2) sf2
363 addDigits1 :: FingerTree (Node (Node a)) -> Digit (Node a) -> Node a -> Digit (Node a) -> FingerTree (Node (Node a)) -> FingerTree (Node (Node a))
364 addDigits1 m1 (One a) b (One c) m2 =
365 appendTree1 m1 (node3 a b c) m2
366 addDigits1 m1 (One a) b (Two c d) m2 =
367 appendTree2 m1 (node2 a b) (node2 c d) m2
368 addDigits1 m1 (One a) b (Three c d e) m2 =
369 appendTree2 m1 (node3 a b c) (node2 d e) m2
370 addDigits1 m1 (One a) b (Four c d e f) m2 =
371 appendTree2 m1 (node3 a b c) (node3 d e f) m2
372 addDigits1 m1 (Two a b) c (One d) m2 =
373 appendTree2 m1 (node2 a b) (node2 c d) m2
374 addDigits1 m1 (Two a b) c (Two d e) m2 =
375 appendTree2 m1 (node3 a b c) (node2 d e) m2
376 addDigits1 m1 (Two a b) c (Three d e f) m2 =
377 appendTree2 m1 (node3 a b c) (node3 d e f) m2
378 addDigits1 m1 (Two a b) c (Four d e f g) m2 =
379 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
380 addDigits1 m1 (Three a b c) d (One e) m2 =
381 appendTree2 m1 (node3 a b c) (node2 d e) m2
382 addDigits1 m1 (Three a b c) d (Two e f) m2 =
383 appendTree2 m1 (node3 a b c) (node3 d e f) m2
384 addDigits1 m1 (Three a b c) d (Three e f g) m2 =
385 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
386 addDigits1 m1 (Three a b c) d (Four e f g h) m2 =
387 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
388 addDigits1 m1 (Four a b c d) e (One f) m2 =
389 appendTree2 m1 (node3 a b c) (node3 d e f) m2
390 addDigits1 m1 (Four a b c d) e (Two f g) m2 =
391 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
392 addDigits1 m1 (Four a b c d) e (Three f g h) m2 =
393 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
394 addDigits1 m1 (Four a b c d) e (Four f g h i) m2 =
395 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
397 appendTree2 :: FingerTree (Node a) -> Node a -> Node a -> FingerTree (Node a) -> FingerTree (Node a)
398 appendTree2 Empty a b xs =
399 a `consTree` b `consTree` xs
400 appendTree2 xs a b Empty =
401 xs `snocTree` a `snocTree` b
402 appendTree2 (Single x) a b xs =
403 x `consTree` a `consTree` b `consTree` xs
404 appendTree2 xs a b (Single x) =
405 xs `snocTree` a `snocTree` b `snocTree` x
406 appendTree2 (Deep s1 pr1 m1 sf1) a b (Deep s2 pr2 m2 sf2) =
407 Deep (s1 + size a + size b + s2) pr1 (addDigits2 m1 sf1 a b pr2 m2) sf2
409 addDigits2 :: FingerTree (Node (Node a)) -> Digit (Node a) -> Node a -> Node a -> Digit (Node a) -> FingerTree (Node (Node a)) -> FingerTree (Node (Node a))
410 addDigits2 m1 (One a) b c (One d) m2 =
411 appendTree2 m1 (node2 a b) (node2 c d) m2
412 addDigits2 m1 (One a) b c (Two d e) m2 =
413 appendTree2 m1 (node3 a b c) (node2 d e) m2
414 addDigits2 m1 (One a) b c (Three d e f) m2 =
415 appendTree2 m1 (node3 a b c) (node3 d e f) m2
416 addDigits2 m1 (One a) b c (Four d e f g) m2 =
417 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
418 addDigits2 m1 (Two a b) c d (One e) m2 =
419 appendTree2 m1 (node3 a b c) (node2 d e) m2
420 addDigits2 m1 (Two a b) c d (Two e f) m2 =
421 appendTree2 m1 (node3 a b c) (node3 d e f) m2
422 addDigits2 m1 (Two a b) c d (Three e f g) m2 =
423 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
424 addDigits2 m1 (Two a b) c d (Four e f g h) m2 =
425 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
426 addDigits2 m1 (Three a b c) d e (One f) m2 =
427 appendTree2 m1 (node3 a b c) (node3 d e f) m2
428 addDigits2 m1 (Three a b c) d e (Two f g) m2 =
429 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
430 addDigits2 m1 (Three a b c) d e (Three f g h) m2 =
431 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
432 addDigits2 m1 (Three a b c) d e (Four f g h i) m2 =
433 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
434 addDigits2 m1 (Four a b c d) e f (One g) m2 =
435 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
436 addDigits2 m1 (Four a b c d) e f (Two g h) m2 =
437 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
438 addDigits2 m1 (Four a b c d) e f (Three g h i) m2 =
439 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
440 addDigits2 m1 (Four a b c d) e f (Four g h i j) m2 =
441 appendTree4 m1 (node3 a b c) (node3 d e f) (node2 g h) (node2 i j) m2
443 appendTree3 :: FingerTree (Node a) -> Node a -> Node a -> Node a -> FingerTree (Node a) -> FingerTree (Node a)
444 appendTree3 Empty a b c xs =
445 a `consTree` b `consTree` c `consTree` xs
446 appendTree3 xs a b c Empty =
447 xs `snocTree` a `snocTree` b `snocTree` c
448 appendTree3 (Single x) a b c xs =
449 x `consTree` a `consTree` b `consTree` c `consTree` xs
450 appendTree3 xs a b c (Single x) =
451 xs `snocTree` a `snocTree` b `snocTree` c `snocTree` x
452 appendTree3 (Deep s1 pr1 m1 sf1) a b c (Deep s2 pr2 m2 sf2) =
453 Deep (s1 + size a + size b + size c + s2) pr1 (addDigits3 m1 sf1 a b c pr2 m2) sf2
455 addDigits3 :: FingerTree (Node (Node a)) -> Digit (Node a) -> Node a -> Node a -> Node a -> Digit (Node a) -> FingerTree (Node (Node a)) -> FingerTree (Node (Node a))
456 addDigits3 m1 (One a) b c d (One e) m2 =
457 appendTree2 m1 (node3 a b c) (node2 d e) m2
458 addDigits3 m1 (One a) b c d (Two e f) m2 =
459 appendTree2 m1 (node3 a b c) (node3 d e f) m2
460 addDigits3 m1 (One a) b c d (Three e f g) m2 =
461 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
462 addDigits3 m1 (One a) b c d (Four e f g h) m2 =
463 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
464 addDigits3 m1 (Two a b) c d e (One f) m2 =
465 appendTree2 m1 (node3 a b c) (node3 d e f) m2
466 addDigits3 m1 (Two a b) c d e (Two f g) m2 =
467 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
468 addDigits3 m1 (Two a b) c d e (Three f g h) m2 =
469 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
470 addDigits3 m1 (Two a b) c d e (Four f g h i) m2 =
471 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
472 addDigits3 m1 (Three a b c) d e f (One g) m2 =
473 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
474 addDigits3 m1 (Three a b c) d e f (Two g h) m2 =
475 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
476 addDigits3 m1 (Three a b c) d e f (Three g h i) m2 =
477 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
478 addDigits3 m1 (Three a b c) d e f (Four g h i j) m2 =
479 appendTree4 m1 (node3 a b c) (node3 d e f) (node2 g h) (node2 i j) m2
480 addDigits3 m1 (Four a b c d) e f g (One h) m2 =
481 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
482 addDigits3 m1 (Four a b c d) e f g (Two h i) m2 =
483 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
484 addDigits3 m1 (Four a b c d) e f g (Three h i j) m2 =
485 appendTree4 m1 (node3 a b c) (node3 d e f) (node2 g h) (node2 i j) m2
486 addDigits3 m1 (Four a b c d) e f g (Four h i j k) m2 =
487 appendTree4 m1 (node3 a b c) (node3 d e f) (node3 g h i) (node2 j k) m2
489 appendTree4 :: FingerTree (Node a) -> Node a -> Node a -> Node a -> Node a -> FingerTree (Node a) -> FingerTree (Node a)
490 appendTree4 Empty a b c d xs =
491 a `consTree` b `consTree` c `consTree` d `consTree` xs
492 appendTree4 xs a b c d Empty =
493 xs `snocTree` a `snocTree` b `snocTree` c `snocTree` d
494 appendTree4 (Single x) a b c d xs =
495 x `consTree` a `consTree` b `consTree` c `consTree` d `consTree` xs
496 appendTree4 xs a b c d (Single x) =
497 xs `snocTree` a `snocTree` b `snocTree` c `snocTree` d `snocTree` x
498 appendTree4 (Deep s1 pr1 m1 sf1) a b c d (Deep s2 pr2 m2 sf2) =
499 Deep (s1 + size a + size b + size c + size d + s2) pr1 (addDigits4 m1 sf1 a b c d pr2 m2) sf2
501 addDigits4 :: FingerTree (Node (Node a)) -> Digit (Node a) -> Node a -> Node a -> Node a -> Node a -> Digit (Node a) -> FingerTree (Node (Node a)) -> FingerTree (Node (Node a))
502 addDigits4 m1 (One a) b c d e (One f) m2 =
503 appendTree2 m1 (node3 a b c) (node3 d e f) m2
504 addDigits4 m1 (One a) b c d e (Two f g) m2 =
505 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
506 addDigits4 m1 (One a) b c d e (Three f g h) m2 =
507 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
508 addDigits4 m1 (One a) b c d e (Four f g h i) m2 =
509 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
510 addDigits4 m1 (Two a b) c d e f (One g) m2 =
511 appendTree3 m1 (node3 a b c) (node2 d e) (node2 f g) m2
512 addDigits4 m1 (Two a b) c d e f (Two g h) m2 =
513 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
514 addDigits4 m1 (Two a b) c d e f (Three g h i) m2 =
515 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
516 addDigits4 m1 (Two a b) c d e f (Four g h i j) m2 =
517 appendTree4 m1 (node3 a b c) (node3 d e f) (node2 g h) (node2 i j) m2
518 addDigits4 m1 (Three a b c) d e f g (One h) m2 =
519 appendTree3 m1 (node3 a b c) (node3 d e f) (node2 g h) m2
520 addDigits4 m1 (Three a b c) d e f g (Two h i) m2 =
521 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
522 addDigits4 m1 (Three a b c) d e f g (Three h i j) m2 =
523 appendTree4 m1 (node3 a b c) (node3 d e f) (node2 g h) (node2 i j) m2
524 addDigits4 m1 (Three a b c) d e f g (Four h i j k) m2 =
525 appendTree4 m1 (node3 a b c) (node3 d e f) (node3 g h i) (node2 j k) m2
526 addDigits4 m1 (Four a b c d) e f g h (One i) m2 =
527 appendTree3 m1 (node3 a b c) (node3 d e f) (node3 g h i) m2
528 addDigits4 m1 (Four a b c d) e f g h (Two i j) m2 =
529 appendTree4 m1 (node3 a b c) (node3 d e f) (node2 g h) (node2 i j) m2
530 addDigits4 m1 (Four a b c d) e f g h (Three i j k) m2 =
531 appendTree4 m1 (node3 a b c) (node3 d e f) (node3 g h i) (node2 j k) m2
532 addDigits4 m1 (Four a b c d) e f g h (Four i j k l) m2 =
533 appendTree4 m1 (node3 a b c) (node3 d e f) (node3 g h i) (node3 j k l) m2
535 ------------------------------------------------------------------------
537 ------------------------------------------------------------------------
539 -- | /O(1)/. Is this the empty sequence?
540 null :: Seq a -> Bool
541 null (Seq Empty) = True
544 -- | /O(1)/. The number of elements in the sequence.
545 length :: Seq a -> Int
546 length (Seq xs) = size xs
550 data Maybe2 a b = Nothing2 | Just2 a b
552 -- | View of the left end of a sequence.
554 = EmptyL -- ^ empty sequence
555 | a :< Seq a -- ^ leftmost element and the rest of the sequence
559 instance Eq a => Eq (ViewL a)
560 instance Show a => Show (ViewL a)
564 instance Functor ViewL where
565 fmap _ EmptyL = EmptyL
566 fmap f (x :< xs) = f x :< fmap f xs
568 -- | /O(1)/. Analyse the left end of a sequence.
569 viewl :: Seq a -> ViewL a
570 viewl (Seq xs) = case viewLTree xs of
572 Just2 (Elem x) xs' -> x :< Seq xs'
574 {-# SPECIALIZE viewLTree :: FingerTree (Elem a) -> Maybe2 (Elem a) (FingerTree (Elem a)) #-}
575 {-# SPECIALIZE viewLTree :: FingerTree (Node a) -> Maybe2 (Node a) (FingerTree (Node a)) #-}
576 viewLTree :: Sized a => FingerTree a -> Maybe2 a (FingerTree a)
577 viewLTree Empty = Nothing2
578 viewLTree (Single a) = Just2 a Empty
579 viewLTree (Deep s (One a) m sf) = Just2 a (case viewLTree m of
580 Nothing2 -> digitToTree sf
581 Just2 b m' -> Deep (s - size a) (nodeToDigit b) m' sf)
582 viewLTree (Deep s (Two a b) m sf) =
583 Just2 a (Deep (s - size a) (One b) m sf)
584 viewLTree (Deep s (Three a b c) m sf) =
585 Just2 a (Deep (s - size a) (Two b c) m sf)
586 viewLTree (Deep s (Four a b c d) m sf) =
587 Just2 a (Deep (s - size a) (Three b c d) m sf)
589 -- | View of the right end of a sequence.
591 = EmptyR -- ^ empty sequence
592 | Seq a :> a -- ^ the sequence minus the rightmost element,
593 -- and the rightmost element
597 instance Eq a => Eq (ViewR a)
598 instance Show a => Show (ViewR a)
601 instance Functor ViewR where
602 fmap _ EmptyR = EmptyR
603 fmap f (xs :> x) = fmap f xs :> f x
605 -- | /O(1)/. Analyse the right end of a sequence.
606 viewr :: Seq a -> ViewR a
607 viewr (Seq xs) = case viewRTree xs of
609 Just2 xs' (Elem x) -> Seq xs' :> x
611 {-# SPECIALIZE viewRTree :: FingerTree (Elem a) -> Maybe2 (FingerTree (Elem a)) (Elem a) #-}
612 {-# SPECIALIZE viewRTree :: FingerTree (Node a) -> Maybe2 (FingerTree (Node a)) (Node a) #-}
613 viewRTree :: Sized a => FingerTree a -> Maybe2 (FingerTree a) a
614 viewRTree Empty = Nothing2
615 viewRTree (Single z) = Just2 Empty z
616 viewRTree (Deep s pr m (One z)) = Just2 (case viewRTree m of
617 Nothing2 -> digitToTree pr
618 Just2 m' y -> Deep (s - size z) pr m' (nodeToDigit y)) z
619 viewRTree (Deep s pr m (Two y z)) =
620 Just2 (Deep (s - size z) pr m (One y)) z
621 viewRTree (Deep s pr m (Three x y z)) =
622 Just2 (Deep (s - size z) pr m (Two x y)) z
623 viewRTree (Deep s pr m (Four w x y z)) =
624 Just2 (Deep (s - size z) pr m (Three w x y)) z
628 -- | /O(log(min(i,n-i)))/. The element at the specified position
629 index :: Seq a -> Int -> a
631 | 0 <= i && i < size xs = case lookupTree (-i) xs of
632 Place _ (Elem x) -> x
633 | otherwise = error "index out of bounds"
635 data Place a = Place {-# UNPACK #-} !Int a
640 {-# SPECIALIZE lookupTree :: Int -> FingerTree (Elem a) -> Place (Elem a) #-}
641 {-# SPECIALIZE lookupTree :: Int -> FingerTree (Node a) -> Place (Node a) #-}
642 lookupTree :: Sized a => Int -> FingerTree a -> Place a
643 lookupTree _ Empty = error "lookupTree of empty tree"
644 lookupTree i (Single x) = Place i x
645 lookupTree i (Deep _ pr m sf)
646 | vpr > 0 = lookupDigit i pr
647 | vm > 0 = case lookupTree vpr m of
648 Place i' xs -> lookupNode i' xs
649 | otherwise = lookupDigit vm sf
650 where vpr = i + size pr
653 {-# SPECIALIZE lookupNode :: Int -> Node (Elem a) -> Place (Elem a) #-}
654 {-# SPECIALIZE lookupNode :: Int -> Node (Node a) -> Place (Node a) #-}
655 lookupNode :: Sized a => Int -> Node a -> Place a
656 lookupNode i (Node2 _ a b)
658 | otherwise = Place va b
659 where va = i + size a
660 lookupNode i (Node3 _ a b c)
662 | vab > 0 = Place va b
663 | otherwise = Place vab c
664 where va = i + size a
667 {-# SPECIALIZE lookupDigit :: Int -> Digit (Elem a) -> Place (Elem a) #-}
668 {-# SPECIALIZE lookupDigit :: Int -> Digit (Node a) -> Place (Node a) #-}
669 lookupDigit :: Sized a => Int -> Digit a -> Place a
670 lookupDigit i (One a) = Place i a
671 lookupDigit i (Two a b)
673 | otherwise = Place va b
674 where va = i + size a
675 lookupDigit i (Three a b c)
677 | vab > 0 = Place va b
678 | otherwise = Place vab c
679 where va = i + size a
681 lookupDigit i (Four a b c d)
683 | vab > 0 = Place va b
684 | vabc > 0 = Place vab c
685 | otherwise = Place vabc d
686 where va = i + size a
690 -- | /O(log(min(i,n-i)))/. Replace the element at the specified position
691 update :: Int -> a -> Seq a -> Seq a
692 update i x = adjust (const x) i
694 -- | /O(log(min(i,n-i)))/. Update the element at the specified position
695 adjust :: (a -> a) -> Int -> Seq a -> Seq a
697 | 0 <= i && i < size xs = Seq (adjustTree (const (fmap f)) (-i) xs)
700 {-# SPECIALIZE adjustTree :: (Int -> Elem a -> Elem a) -> Int -> FingerTree (Elem a) -> FingerTree (Elem a) #-}
701 {-# SPECIALIZE adjustTree :: (Int -> Node a -> Node a) -> Int -> FingerTree (Node a) -> FingerTree (Node a) #-}
702 adjustTree :: Sized a => (Int -> a -> a) ->
703 Int -> FingerTree a -> FingerTree a
704 adjustTree _ _ Empty = error "adjustTree of empty tree"
705 adjustTree f i (Single x) = Single (f i x)
706 adjustTree f i (Deep s pr m sf)
707 | vpr > 0 = Deep s (adjustDigit f i pr) m sf
708 | vm > 0 = Deep s pr (adjustTree (adjustNode f) vpr m) sf
709 | otherwise = Deep s pr m (adjustDigit f vm sf)
710 where vpr = i + size pr
713 {-# SPECIALIZE adjustNode :: (Int -> Elem a -> Elem a) -> Int -> Node (Elem a) -> Node (Elem a) #-}
714 {-# SPECIALIZE adjustNode :: (Int -> Node a -> Node a) -> Int -> Node (Node a) -> Node (Node a) #-}
715 adjustNode :: Sized a => (Int -> a -> a) -> Int -> Node a -> Node a
716 adjustNode f i (Node2 s a b)
717 | va > 0 = Node2 s (f i a) b
718 | otherwise = Node2 s a (f va b)
719 where va = i + size a
720 adjustNode f i (Node3 s a b c)
721 | va > 0 = Node3 s (f i a) b c
722 | vab > 0 = Node3 s a (f va b) c
723 | otherwise = Node3 s a b (f vab c)
724 where va = i + size a
727 {-# SPECIALIZE adjustDigit :: (Int -> Elem a -> Elem a) -> Int -> Digit (Elem a) -> Digit (Elem a) #-}
728 {-# SPECIALIZE adjustDigit :: (Int -> Node a -> Node a) -> Int -> Digit (Node a) -> Digit (Node a) #-}
729 adjustDigit :: Sized a => (Int -> a -> a) -> Int -> Digit a -> Digit a
730 adjustDigit f i (One a) = One (f i a)
731 adjustDigit f i (Two a b)
732 | va > 0 = Two (f i a) b
733 | otherwise = Two a (f va b)
734 where va = i + size a
735 adjustDigit f i (Three a b c)
736 | va > 0 = Three (f i a) b c
737 | vab > 0 = Three a (f va b) c
738 | otherwise = Three a b (f vab c)
739 where va = i + size a
741 adjustDigit f i (Four a b c d)
742 | va > 0 = Four (f i a) b c d
743 | vab > 0 = Four a (f va b) c d
744 | vabc > 0 = Four a b (f vab c) d
745 | otherwise = Four a b c (f vabc d)
746 where va = i + size a
752 -- | /O(log(min(i,n-i)))/. The first @i@ elements of a sequence.
753 take :: Int -> Seq a -> Seq a
754 take i = fst . splitAt i
756 -- | /O(log(min(i,n-i)))/. Elements of a sequence after the first @i@.
757 drop :: Int -> Seq a -> Seq a
758 drop i = snd . splitAt i
760 -- | /O(log(min(i,n-i)))/. Split a sequence at a given position.
761 splitAt :: Int -> Seq a -> (Seq a, Seq a)
762 splitAt i (Seq xs) = (Seq l, Seq r)
763 where (l, r) = split i xs
765 split :: Int -> FingerTree (Elem a) ->
766 (FingerTree (Elem a), FingerTree (Elem a))
767 split i Empty = i `seq` (Empty, Empty)
769 | size xs > i = (l, consTree x r)
770 | otherwise = (xs, Empty)
771 where Split l x r = splitTree (-i) xs
773 data Split t a = Split t a t
778 {-# SPECIALIZE splitTree :: Int -> FingerTree (Elem a) -> Split (FingerTree (Elem a)) (Elem a) #-}
779 {-# SPECIALIZE splitTree :: Int -> FingerTree (Node a) -> Split (FingerTree (Node a)) (Node a) #-}
780 splitTree :: Sized a => Int -> FingerTree a -> Split (FingerTree a) a
781 splitTree _ Empty = error "splitTree of empty tree"
782 splitTree i (Single x) = i `seq` Split Empty x Empty
783 splitTree i (Deep _ pr m sf)
784 | vpr > 0 = case splitDigit i pr of
785 Split l x r -> Split (maybe Empty digitToTree l) x (deepL r m sf)
786 | vm > 0 = case splitTree vpr m of
787 Split ml xs mr -> case splitNode (vpr + size ml) xs of
788 Split l x r -> Split (deepR pr ml l) x (deepL r mr sf)
789 | otherwise = case splitDigit vm sf of
790 Split l x r -> Split (deepR pr m l) x (maybe Empty digitToTree r)
791 where vpr = i + size pr
794 {-# SPECIALIZE deepL :: Maybe (Digit (Elem a)) -> FingerTree (Node (Elem a)) -> Digit (Elem a) -> FingerTree (Elem a) #-}
795 {-# SPECIALIZE deepL :: Maybe (Digit (Node a)) -> FingerTree (Node (Node a)) -> Digit (Node a) -> FingerTree (Node a) #-}
796 deepL :: Sized a => Maybe (Digit a) -> FingerTree (Node a) -> Digit a -> FingerTree a
797 deepL Nothing m sf = case viewLTree m of
798 Nothing2 -> digitToTree sf
799 Just2 a m' -> deep (nodeToDigit a) m' sf
800 deepL (Just pr) m sf = deep pr m sf
802 {-# SPECIALIZE deepR :: Digit (Elem a) -> FingerTree (Node (Elem a)) -> Maybe (Digit (Elem a)) -> FingerTree (Elem a) #-}
803 {-# SPECIALIZE deepR :: Digit (Node a) -> FingerTree (Node (Node a)) -> Maybe (Digit (Node a)) -> FingerTree (Node a) #-}
804 deepR :: Sized a => Digit a -> FingerTree (Node a) -> Maybe (Digit a) -> FingerTree a
805 deepR pr m Nothing = case viewRTree m of
806 Nothing2 -> digitToTree pr
807 Just2 m' a -> deep pr m' (nodeToDigit a)
808 deepR pr m (Just sf) = deep pr m sf
810 {-# SPECIALIZE splitNode :: Int -> Node (Elem a) -> Split (Maybe (Digit (Elem a))) (Elem a) #-}
811 {-# SPECIALIZE splitNode :: Int -> Node (Node a) -> Split (Maybe (Digit (Node a))) (Node a) #-}
812 splitNode :: Sized a => Int -> Node a -> Split (Maybe (Digit a)) a
813 splitNode i (Node2 _ a b)
814 | va > 0 = Split Nothing a (Just (One b))
815 | otherwise = Split (Just (One a)) b Nothing
816 where va = i + size a
817 splitNode i (Node3 _ a b c)
818 | va > 0 = Split Nothing a (Just (Two b c))
819 | vab > 0 = Split (Just (One a)) b (Just (One c))
820 | otherwise = Split (Just (Two a b)) c Nothing
821 where va = i + size a
824 {-# SPECIALIZE splitDigit :: Int -> Digit (Elem a) -> Split (Maybe (Digit (Elem a))) (Elem a) #-}
825 {-# SPECIALIZE splitDigit :: Int -> Digit (Node a) -> Split (Maybe (Digit (Node a))) (Node a) #-}
826 splitDigit :: Sized a => Int -> Digit a -> Split (Maybe (Digit a)) a
827 splitDigit i (One a) = i `seq` Split Nothing a Nothing
828 splitDigit i (Two a b)
829 | va > 0 = Split Nothing a (Just (One b))
830 | otherwise = Split (Just (One a)) b Nothing
831 where va = i + size a
832 splitDigit i (Three a b c)
833 | va > 0 = Split Nothing a (Just (Two b c))
834 | vab > 0 = Split (Just (One a)) b (Just (One c))
835 | otherwise = Split (Just (Two a b)) c Nothing
836 where va = i + size a
838 splitDigit i (Four a b c d)
839 | va > 0 = Split Nothing a (Just (Three b c d))
840 | vab > 0 = Split (Just (One a)) b (Just (Two c d))
841 | vabc > 0 = Split (Just (Two a b)) c (Just (One d))
842 | otherwise = Split (Just (Three a b c)) d Nothing
843 where va = i + size a
847 ------------------------------------------------------------------------
849 ------------------------------------------------------------------------
851 -- | /O(n)/. Create a sequence from a finite list of elements.
852 fromList :: [a] -> Seq a
853 fromList = Data.List.foldl' (|>) empty
855 -- | /O(n)/. List of elements of the sequence.
856 toList :: Seq a -> [a]
857 toList = foldr (:) []
859 ------------------------------------------------------------------------
861 ------------------------------------------------------------------------
863 -- | /O(n*t)/. Fold over the elements of a sequence,
864 -- associating to the right.
865 foldr :: (a -> b -> b) -> b -> Seq a -> b
866 foldr f z (Seq xs) = foldrTree f' z xs
867 where f' (Elem x) y = f x y
869 foldrTree :: (a -> b -> b) -> b -> FingerTree a -> b
870 foldrTree _ z Empty = z
871 foldrTree f z (Single x) = x `f` z
872 foldrTree f z (Deep _ pr m sf) =
873 foldrDigit f (foldrTree (flip (foldrNode f)) (foldrDigit f z sf) m) pr
875 foldrDigit :: (a -> b -> b) -> b -> Digit a -> b
876 foldrDigit f z (One a) = a `f` z
877 foldrDigit f z (Two a b) = a `f` (b `f` z)
878 foldrDigit f z (Three a b c) = a `f` (b `f` (c `f` z))
879 foldrDigit f z (Four a b c d) = a `f` (b `f` (c `f` (d `f` z)))
881 foldrNode :: (a -> b -> b) -> b -> Node a -> b
882 foldrNode f z (Node2 _ a b) = a `f` (b `f` z)
883 foldrNode f z (Node3 _ a b c) = a `f` (b `f` (c `f` z))
885 -- | /O(n*t)/. A variant of 'foldr' that has no base case,
886 -- and thus may only be applied to non-empty sequences.
887 foldr1 :: (a -> a -> a) -> Seq a -> a
888 foldr1 f (Seq xs) = getElem (foldr1Tree f' xs)
889 where f' (Elem x) (Elem y) = Elem (f x y)
891 foldr1Tree :: (a -> a -> a) -> FingerTree a -> a
892 foldr1Tree _ Empty = error "foldr1: empty sequence"
893 foldr1Tree _ (Single x) = x
894 foldr1Tree f (Deep _ pr m sf) =
895 foldrDigit f (foldrTree (flip (foldrNode f)) (foldr1Digit f sf) m) pr
897 foldr1Digit :: (a -> a -> a) -> Digit a -> a
898 foldr1Digit f (One a) = a
899 foldr1Digit f (Two a b) = a `f` b
900 foldr1Digit f (Three a b c) = a `f` (b `f` c)
901 foldr1Digit f (Four a b c d) = a `f` (b `f` (c `f` d))
903 -- | /O(n*t)/. Fold over the elements of a sequence,
904 -- associating to the left.
905 foldl :: (a -> b -> a) -> a -> Seq b -> a
906 foldl f z (Seq xs) = foldlTree f' z xs
907 where f' x (Elem y) = f x y
909 foldlTree :: (a -> b -> a) -> a -> FingerTree b -> a
910 foldlTree _ z Empty = z
911 foldlTree f z (Single x) = z `f` x
912 foldlTree f z (Deep _ pr m sf) =
913 foldlDigit f (foldlTree (foldlNode f) (foldlDigit f z pr) m) sf
915 foldlDigit :: (a -> b -> a) -> a -> Digit b -> a
916 foldlDigit f z (One a) = z `f` a
917 foldlDigit f z (Two a b) = (z `f` a) `f` b
918 foldlDigit f z (Three a b c) = ((z `f` a) `f` b) `f` c
919 foldlDigit f z (Four a b c d) = (((z `f` a) `f` b) `f` c) `f` d
921 foldlNode :: (a -> b -> a) -> a -> Node b -> a
922 foldlNode f z (Node2 _ a b) = (z `f` a) `f` b
923 foldlNode f z (Node3 _ a b c) = ((z `f` a) `f` b) `f` c
925 -- | /O(n*t)/. A variant of 'foldl' that has no base case,
926 -- and thus may only be applied to non-empty sequences.
927 foldl1 :: (a -> a -> a) -> Seq a -> a
928 foldl1 f (Seq xs) = getElem (foldl1Tree f' xs)
929 where f' (Elem x) (Elem y) = Elem (f x y)
931 foldl1Tree :: (a -> a -> a) -> FingerTree a -> a
932 foldl1Tree _ Empty = error "foldl1: empty sequence"
933 foldl1Tree _ (Single x) = x
934 foldl1Tree f (Deep _ pr m sf) =
935 foldlDigit f (foldlTree (foldlNode f) (foldl1Digit f pr) m) sf
937 foldl1Digit :: (a -> a -> a) -> Digit a -> a
938 foldl1Digit f (One a) = a
939 foldl1Digit f (Two a b) = a `f` b
940 foldl1Digit f (Three a b c) = (a `f` b) `f` c
941 foldl1Digit f (Four a b c d) = ((a `f` b) `f` c) `f` d
943 ------------------------------------------------------------------------
945 ------------------------------------------------------------------------
947 -- | /O(n*t)/. Fold over the elements of a sequence,
948 -- associating to the right, but strictly.
949 foldr' :: (a -> b -> b) -> b -> Seq a -> b
950 foldr' f z xs = foldl f' id xs z
951 where f' k x z = k $! f x z
953 -- | /O(n*t)/. Monadic fold over the elements of a sequence,
954 -- associating to the right, i.e. from right to left.
955 foldrM :: Monad m => (a -> b -> m b) -> b -> Seq a -> m b
956 foldrM f z xs = foldl f' return xs z
957 where f' k x z = f x z >>= k
959 -- | /O(n*t)/. Fold over the elements of a sequence,
960 -- associating to the left, but strictly.
961 foldl' :: (a -> b -> a) -> a -> Seq b -> a
962 foldl' f z xs = foldr f' id xs z
963 where f' x k z = k $! f z x
965 -- | /O(n*t)/. Monadic fold over the elements of a sequence,
966 -- associating to the left, i.e. from left to right.
967 foldlM :: Monad m => (a -> b -> m a) -> a -> Seq b -> m a
968 foldlM f z xs = foldr f' return xs z
969 where f' x k z = f z x >>= k
971 ------------------------------------------------------------------------
973 ------------------------------------------------------------------------
975 -- | /O(n)/. The reverse of a sequence.
976 reverse :: Seq a -> Seq a
977 reverse (Seq xs) = Seq (reverseTree id xs)
979 reverseTree :: (a -> a) -> FingerTree a -> FingerTree a
980 reverseTree _ Empty = Empty
981 reverseTree f (Single x) = Single (f x)
982 reverseTree f (Deep s pr m sf) =
983 Deep s (reverseDigit f sf)
984 (reverseTree (reverseNode f) m)
987 reverseDigit :: (a -> a) -> Digit a -> Digit a
988 reverseDigit f (One a) = One (f a)
989 reverseDigit f (Two a b) = Two (f b) (f a)
990 reverseDigit f (Three a b c) = Three (f c) (f b) (f a)
991 reverseDigit f (Four a b c d) = Four (f d) (f c) (f b) (f a)
993 reverseNode :: (a -> a) -> Node a -> Node a
994 reverseNode f (Node2 s a b) = Node2 s (f b) (f a)
995 reverseNode f (Node3 s a b c) = Node3 s (f c) (f b) (f a)
999 ------------------------------------------------------------------------
1001 ------------------------------------------------------------------------
1003 instance Arbitrary a => Arbitrary (Seq a) where
1004 arbitrary = liftM Seq arbitrary
1005 coarbitrary (Seq x) = coarbitrary x
1007 instance Arbitrary a => Arbitrary (Elem a) where
1008 arbitrary = liftM Elem arbitrary
1009 coarbitrary (Elem x) = coarbitrary x
1011 instance (Arbitrary a, Sized a) => Arbitrary (FingerTree a) where
1012 arbitrary = sized arb
1013 where arb :: (Arbitrary a, Sized a) => Int -> Gen (FingerTree a)
1014 arb 0 = return Empty
1015 arb 1 = liftM Single arbitrary
1016 arb n = liftM3 deep arbitrary (arb (n `div` 2)) arbitrary
1018 coarbitrary Empty = variant 0
1019 coarbitrary (Single x) = variant 1 . coarbitrary x
1020 coarbitrary (Deep _ pr m sf) =
1021 variant 2 . coarbitrary pr . coarbitrary m . coarbitrary sf
1023 instance (Arbitrary a, Sized a) => Arbitrary (Node a) where
1025 liftM2 node2 arbitrary arbitrary,
1026 liftM3 node3 arbitrary arbitrary arbitrary]
1028 coarbitrary (Node2 _ a b) = variant 0 . coarbitrary a . coarbitrary b
1029 coarbitrary (Node3 _ a b c) =
1030 variant 1 . coarbitrary a . coarbitrary b . coarbitrary c
1032 instance Arbitrary a => Arbitrary (Digit a) where
1034 liftM One arbitrary,
1035 liftM2 Two arbitrary arbitrary,
1036 liftM3 Three arbitrary arbitrary arbitrary,
1037 liftM4 Four arbitrary arbitrary arbitrary arbitrary]
1039 coarbitrary (One a) = variant 0 . coarbitrary a
1040 coarbitrary (Two a b) = variant 1 . coarbitrary a . coarbitrary b
1041 coarbitrary (Three a b c) =
1042 variant 2 . coarbitrary a . coarbitrary b . coarbitrary c
1043 coarbitrary (Four a b c d) =
1044 variant 3 . coarbitrary a . coarbitrary b . coarbitrary c . coarbitrary d
1046 ------------------------------------------------------------------------
1048 ------------------------------------------------------------------------
1053 instance Valid (Elem a) where
1056 instance Valid (Seq a) where
1057 valid (Seq xs) = valid xs
1059 instance (Sized a, Valid a) => Valid (FingerTree a) where
1061 valid (Single x) = valid x
1062 valid (Deep s pr m sf) =
1063 s == size pr + size m + size sf && valid pr && valid m && valid sf
1065 instance (Sized a, Valid a) => Valid (Node a) where
1066 valid (Node2 s a b) = s == size a + size b && valid a && valid b
1067 valid (Node3 s a b c) =
1068 s == size a + size b + size c && valid a && valid b && valid c
1070 instance Valid a => Valid (Digit a) where
1071 valid (One a) = valid a
1072 valid (Two a b) = valid a && valid b
1073 valid (Three a b c) = valid a && valid b && valid c
1074 valid (Four a b c d) = valid a && valid b && valid c && valid d