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20 Nov 2025 01:09PM UTC coverage: 76.993% (+0.07%) from 76.922%
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75.34
/src/Constrained/NumOrd.hs
1
{-# LANGUAGE AllowAmbiguousTypes #-}
2
{-# LANGUAGE ConstraintKinds #-}
3
{-# LANGUAGE CPP #-}
4
{-# LANGUAGE DataKinds #-}
5
{-# LANGUAGE DefaultSignatures #-}
6
{-# LANGUAGE DerivingVia #-}
7
{-# LANGUAGE FlexibleContexts #-}
8
{-# LANGUAGE FlexibleInstances #-}
9
{-# LANGUAGE GADTs #-}
10
{-# LANGUAGE LambdaCase #-}
11
{-# LANGUAGE PatternSynonyms #-}
12
{-# LANGUAGE ScopedTypeVariables #-}
13
{-# LANGUAGE StandaloneDeriving #-}
14
{-# LANGUAGE TypeApplications #-}
15
{-# LANGUAGE TypeFamilies #-}
16
{-# LANGUAGE TypeOperators #-}
17
{-# LANGUAGE UndecidableInstances #-}
18
{-# LANGUAGE UndecidableSuperClasses #-}
19
{-# LANGUAGE ViewPatterns #-}
20
-- Random Natural, Arbitrary Natural, Uniform Natural
21
{-# OPTIONS_GHC -Wno-orphans #-}
22

23
-- | Everything we need to deal with numbers and comparisons between them
24
module Constrained.NumOrd (
25
  NumSpec (..),
26
  (>.),
27
  (<.),
28
  (-.),
29
  (>=.),
30
  (<=.),
31
  (+.),
32
  (*.),
33
  negate_,
34
  cardinality,
35
  caseBoolSpec,
36
  addSpecInt,
37
  emptyNumSpec,
38
  cardinalNumSpec,
39
  combineNumSpec,
40
  genFromNumSpec,
41
  shrinkWithNumSpec,
42
  fixupWithTypeSpec,
43
  conformsToNumSpec,
44
  toPredsNumSpec,
45
  OrdLike (..),
46
  MaybeBounded (..),
47
  NumLike (..),
48
  HasDivision (..),
49
  Numeric,
50
  Number,
51
  nubOrd,
52
  IntW (..),
53
  OrdW (..),
54
) where
55

56
import Constrained.AbstractSyntax
57
import Constrained.Base
58
import Constrained.Conformance
59
import Constrained.Core (Value (..), unionWithMaybe)
60
import Constrained.FunctionSymbol
61
import Constrained.GenT
62
import Constrained.Generic
63
import Constrained.List
64
import Constrained.PrettyUtils
65
import Control.Applicative ((<|>))
66
import Control.Arrow (first)
67
import Data.Containers.ListUtils
68
import Data.Foldable
69
import Data.Kind
70
import Data.List (nub)
71
import Data.List.NonEmpty (NonEmpty ((:|)))
72
import qualified Data.List.NonEmpty as NE
73
import Data.Maybe
74
import qualified Data.Set as Set
75
import Data.Typeable (typeOf)
76
import Data.Word
77
import GHC.Int
78
import GHC.Natural
79
import GHC.Real
80
import System.Random.Stateful (Random (..), Uniform (..))
81
import Test.QuickCheck (Arbitrary (arbitrary, shrink), choose, frequency)
82

83
-- | Witnesses for comparison operations (<=. and <. and <=. and >=.) on numbers
84
-- The other operations are defined in terms of these.
85
data OrdW (dom :: [Type]) (rng :: Type) where
86
  LessOrEqualW :: OrdLike a => OrdW '[a, a] Bool
87
  LessW :: OrdLike a => OrdW '[a, a] Bool
88
  GreaterOrEqualW :: OrdLike a => OrdW '[a, a] Bool
89
  GreaterW :: OrdLike a => OrdW '[a, a] Bool
90

91
deriving instance Eq (OrdW ds r)
×
92

93
instance Show (OrdW ds r) where
×
94
  show LessOrEqualW = "<=."
2✔
95
  show LessW = "<."
2✔
96
  show GreaterOrEqualW = ">=."
×
97
  show GreaterW = ">."
2✔
98

99
instance Semantics OrdW where
100
  semantics LessOrEqualW = (<=)
2✔
101
  semantics LessW = (<)
2✔
102
  semantics GreaterW = (>)
2✔
103
  semantics GreaterOrEqualW = (>=)
2✔
104

105
instance Syntax OrdW where
2✔
106
  isInfix _ = True
2✔
107

108
-- =============================================
109
-- OrdLike. Ord for Numbers in the Logic
110
-- =============================================
111

112
-- | Ancillary things we need to be able to implement `Logic` instances for
113
-- `OrdW` that make sense for a given type we are comparing things on.
114
class (Ord a, HasSpec a) => OrdLike a where
115
  leqSpec :: a -> Specification a
116
  default leqSpec ::
117
    ( GenericRequires a
118
    , OrdLike (SimpleRep a)
119
    ) =>
120
    a ->
121
    Specification a
122
  leqSpec = fromSimpleRepSpec . leqSpec . toSimpleRep
×
123

124
  ltSpec :: a -> Specification a
125
  default ltSpec ::
126
    ( OrdLike (SimpleRep a)
127
    , GenericRequires a
128
    ) =>
129
    a ->
130
    Specification a
131
  ltSpec = fromSimpleRepSpec . ltSpec . toSimpleRep
×
132

133
  geqSpec :: a -> Specification a
134
  default geqSpec ::
135
    ( OrdLike (SimpleRep a)
136
    , GenericRequires a
137
    ) =>
138
    a ->
139
    Specification a
140
  geqSpec = fromSimpleRepSpec . geqSpec . toSimpleRep
×
141

142
  gtSpec :: a -> Specification a
143
  default gtSpec ::
144
    ( OrdLike (SimpleRep a)
145
    , GenericRequires a
146
    ) =>
147
    a ->
148
    Specification a
149
  gtSpec = fromSimpleRepSpec . gtSpec . toSimpleRep
×
150

151
-- | This instance should be general enough for every type of Number that has a NumSpec as its TypeSpec
152
instance {-# OVERLAPPABLE #-} (Ord a, HasSpec a, MaybeBounded a, Num a, TypeSpec a ~ NumSpec a) => OrdLike a where
153
  leqSpec l = typeSpec $ NumSpecInterval Nothing (Just l)
2✔
154
  ltSpec l
2✔
155
    | Just b <- lowerBound
2✔
156
    , l == b =
1✔
157
        ErrorSpec (pure ("ltSpec @" ++ show (typeOf l) ++ " " ++ show l))
×
158
    | otherwise = typeSpec $ NumSpecInterval Nothing (Just (l - 1))
1✔
159
  geqSpec l = typeSpec $ NumSpecInterval (Just l) Nothing
2✔
160
  gtSpec l
2✔
161
    | Just b <- upperBound
2✔
162
    , l == b =
1✔
163
        ErrorSpec (pure ("gtSpec @" ++ show (typeOf l) ++ " " ++ show l))
×
164
    | otherwise = typeSpec $ NumSpecInterval (Just (l + 1)) Nothing
1✔
165

166
-- ========================================================================
167
-- helper functions for the TypeSpec for Numbers
168
-- ========================================================================
169

170
-- | Helper class for talking about things that _might_ be `Bounded`
171
class MaybeBounded a where
172
  lowerBound :: Maybe a
173
  upperBound :: Maybe a
174

175
  default lowerBound :: Bounded a => Maybe a
176
  lowerBound = Just minBound
2✔
177

178
  default upperBound :: Bounded a => Maybe a
179
  upperBound = Just maxBound
2✔
180

181
newtype Unbounded a = Unbounded a
182

183
instance MaybeBounded (Unbounded a) where
184
  lowerBound = Nothing
2✔
185
  upperBound = Nothing
2✔
186

187
instance MaybeBounded Int
2✔
188

189
instance MaybeBounded Int64
2✔
190

191
instance MaybeBounded Int32
2✔
192

193
instance MaybeBounded Int16
2✔
194

195
instance MaybeBounded Int8
2✔
196

197
instance MaybeBounded Word64
2✔
198

199
instance MaybeBounded Word32
2✔
200

201
instance MaybeBounded Word16
2✔
202

203
instance MaybeBounded Word8
2✔
204

205
deriving via Unbounded Integer instance MaybeBounded Integer
2✔
206

207
deriving via Unbounded (Ratio Integer) instance MaybeBounded (Ratio Integer)
×
208

209
deriving via Unbounded Float instance MaybeBounded Float
2✔
210

211
deriving via Unbounded Double instance MaybeBounded Double
2✔
212

213
instance MaybeBounded Natural where
214
  lowerBound = Just 0
2✔
215
  upperBound = Nothing
2✔
216

217
-- ===================================================================
218
-- The TypeSpec for numbers
219
-- ===================================================================
220

221
-- | t`TypeSpec` for numbers - represented as a single interval
222
data NumSpec n = NumSpecInterval (Maybe n) (Maybe n)
223

224
instance Ord n => Eq (NumSpec n) where
×
225
  NumSpecInterval ml mh == NumSpecInterval ml' mh'
2✔
226
    | isEmpty ml mh = isEmpty ml' mh'
2✔
227
    | isEmpty ml' mh' = isEmpty ml mh
1✔
228
    | otherwise = ml == ml' && mh == mh'
1✔
229
    where
230
      isEmpty (Just a) (Just b) = a > b
2✔
231
      isEmpty _ _ = False
2✔
232

233
instance Show n => Show (NumSpec n) where
×
234
  show (NumSpecInterval ml mu) = lb ++ ".." ++ ub
2✔
235
    where
236
      lb = "[" ++ maybe "" show ml
2✔
237
      ub = maybe "" show mu ++ "]"
2✔
238

239
instance Ord n => Semigroup (NumSpec n) where
×
240
  NumSpecInterval ml mu <> NumSpecInterval ml' mu' =
2✔
241
    NumSpecInterval
2✔
242
      (unionWithMaybe max ml ml')
2✔
243
      (unionWithMaybe min mu mu')
2✔
244

245
instance Ord n => Monoid (NumSpec n) where
×
246
  mempty = NumSpecInterval Nothing Nothing
2✔
247

248
-- ===========================================
249
-- Arbitrary for Num like things
250
-- ===========================================
251

252
instance (Arbitrary a, Ord a) => Arbitrary (NumSpec a) where
253
  arbitrary = do
2✔
254
    m <- arbitrary
2✔
255
    m' <- arbitrary
2✔
256
    frequency [(10, pure $ mkLoHiInterval m m'), (1, pure $ NumSpecInterval m m')]
2✔
257
    where
258
      mkLoHiInterval (Just a) (Just b) = NumSpecInterval (Just $ min a b) (Just $ max a b)
2✔
259
      mkLoHiInterval m m' = NumSpecInterval m m'
2✔
260
  shrink (NumSpecInterval m m') =
×
261
    uncurry NumSpecInterval <$> shrink (m, m')
×
262

263
#if !MIN_VERSION_QuickCheck(2, 17, 0)
264
instance Arbitrary Natural where
265
  arbitrary = wordToNatural . abs <$> arbitrary
×
266
  shrink n = [wordToNatural w | w <- shrink (naturalToWord n)]
2✔
267
#endif
268

269
instance Uniform Natural where
270
  uniformM g = wordToNatural . abs <$> uniformM g
×
271

272
instance Random Natural where
×
273
  randomR (lo, hi) g = first fromIntegral $ randomR (toInteger lo, toInteger hi) g
2✔
274

275
instance Random (Ratio Integer) where
×
276
  randomR (lo, hi) g =
2✔
277
    let (r, g') = random g
2✔
278
     in (lo + (hi - lo) * r, g')
1✔
279
  random g =
2✔
280
    let (d, g') = first ((+ 1) . abs) $ random g
2✔
281
        (n, g'') = randomR (0, d) g'
2✔
282
     in (n % d, g'')
1✔
283

284
-- ==============================================================================
285
-- Operations on NumSpec, that give it the required properties of a TypeSpec
286
-- ==============================================================================
287

288
-- | Admits anything
289
emptyNumSpec :: Ord a => NumSpec a
290
emptyNumSpec = mempty
2✔
291

292
guardNumSpec ::
293
  (Ord n, HasSpec n, TypeSpec n ~ NumSpec n) =>
294
  [String] ->
295
  NumSpec n ->
296
  Specification n
297
guardNumSpec msg s@(NumSpecInterval (Just a) (Just b))
2✔
298
  | a > b = ErrorSpec ("NumSpec has low bound greater than hi bound" :| (("   " ++ show s) : msg))
2✔
299
  | a == b = equalSpec a
2✔
300
guardNumSpec _ s = typeSpec s
2✔
301

302
-- | Conjunction
303
combineNumSpec ::
304
  (HasSpec n, Ord n, TypeSpec n ~ NumSpec n) =>
305
  NumSpec n ->
306
  NumSpec n ->
307
  Specification n
308
combineNumSpec s s' = guardNumSpec ["when combining two NumSpecs", "   " ++ show s, "   " ++ show s'] (s <> s')
2✔
309

310
-- | Generate a value that satisfies the spec
311
genFromNumSpec ::
312
  (MonadGenError m, Show n, Random n, Ord n, Num n, MaybeBounded n) =>
313
  NumSpec n ->
314
  GenT m n
315
genFromNumSpec (NumSpecInterval ml mu) = do
2✔
316
  n <- sizeT
2✔
317
  pureGen . choose =<< constrainInterval (ml <|> lowerBound) (mu <|> upperBound) (fromIntegral n)
2✔
318

319
-- TODO: fixme
320

321
-- | Try to shrink using a `NumSpec`
322
shrinkWithNumSpec :: Arbitrary n => NumSpec n -> n -> [n]
323
shrinkWithNumSpec _ = shrink
2✔
324

325
-- TODO: fixme
326

327
fixupWithNumSpec :: Arbitrary n => NumSpec n -> n -> Maybe n
328
fixupWithNumSpec _ = listToMaybe . shrink
2✔
329

330
constrainInterval ::
331
  (MonadGenError m, Ord a, Num a, Show a) => Maybe a -> Maybe a -> Integer -> m (a, a)
332
constrainInterval ml mu r =
2✔
333
  case (ml, mu) of
2✔
334
    (Nothing, Nothing) -> pure (-r', r')
2✔
335
    (Just l, Nothing)
336
      | l < 0 -> pure (max l (negate r'), r')
2✔
337
      | otherwise -> pure (l, l + 2 * r')
1✔
338
    (Nothing, Just u)
339
      | u > 0 -> pure (negate r', min u r')
2✔
340
      | otherwise -> pure (u - r' - r', u)
1✔
341
    (Just l, Just u)
342
      | l > u -> genError ("bad interval: " ++ show l ++ " " ++ show u)
1✔
343
      | u < 0 -> pure (safeSub l (safeSub l u r') r', u)
2✔
344
      | l >= 0 -> pure (l, safeAdd u (safeAdd u l r') r')
2✔
345
      -- TODO: this is a bit suspect if the bounds are lopsided
346
      | otherwise -> pure (max l (-r'), min u r')
1✔
347
  where
348
    r' = abs $ fromInteger r
2✔
349
    safeSub l a b
2✔
350
      | a - b > a = l
2✔
351
      | otherwise = max l (a - b)
1✔
352
    safeAdd u a b
2✔
353
      | a + b < a = u
2✔
354
      | otherwise = min u (a + b)
1✔
355

356
-- | Check that a value is in the spec
357
conformsToNumSpec :: Ord n => n -> NumSpec n -> Bool
358
conformsToNumSpec i (NumSpecInterval ml mu) = maybe True (<= i) ml && maybe True (i <=) mu
2✔
359

360
-- =======================================================================
361
-- Several of the methods of HasSpec that have default implementations
362
-- could benefit from type specific implementations for numbers. Those
363
-- implementations are found here
364
-- =====================================================================
365

366
-- | Builds a MemberSpec, but returns an Error spec if the list is empty
367
nubOrdMemberSpec :: Ord a => String -> [a] -> Specification a
368
nubOrdMemberSpec message xs =
2✔
369
  memberSpec
2✔
370
    (nubOrd xs)
2✔
UNCOV
371
    ( NE.fromList
×
372
        [ "In call to nubOrdMemberSpec"
×
373
        , "Called from context"
×
374
        , message
×
375
        , "The input is the empty list."
×
376
        ]
377
    )
378

379
lowBound :: Bounded n => Maybe n -> n
380
lowBound Nothing = minBound
2✔
UNCOV
381
lowBound (Just n) = n
×
382

383
highBound :: Bounded n => Maybe n -> n
384
highBound Nothing = maxBound
2✔
UNCOV
385
highBound (Just n) = n
×
386

387
-- | The exact count of the number elements in a Bounded NumSpec
388
countSpec :: forall n. (Bounded n, Integral n) => NumSpec n -> Integer
389
countSpec (NumSpecInterval lo hi) = if lo > hi then 0 else toInteger high - toInteger low + 1
1✔
390
  where
391
    high = highBound hi
2✔
392
    low = lowBound lo
2✔
393

394
-- | The exact number of elements in a Bounded Integral type.
395
finiteSize :: forall n. (Integral n, Bounded n) => Integer
396
finiteSize = toInteger (maxBound @n) - toInteger (minBound @n) + 1
2✔
397

398
-- | This is an optimizing version of  TypeSpec :: TypeSpec n -> [n] -> Specification n
399
--   for Bounded NumSpecs.
400
--                    notInNumSpec :: Bounded n => TypeSpec n -> [n] -> Specification n
401
--   We use this function to specialize the (HasSpec t) method 'typeSpecOpt' for Bounded n.
402
--   So given (TypeSpec interval badlist) we might want to transform it to (MemberSpec goodlist)
403
--   There are 2 opportunities where this can payoff big time.
404
--   1) Suppose the total count of the elements in the interval is < length badlist
405
--      we can then return (MemberSpec (filter elements (`notElem` badlist)))
406
--      this must be smaller than (TypeSpec interval badlist) because the filtered list must be smaller than badlist
407
--   2) Suppose the type 't' is finite with size N. If the length of the badlist > (N/2), then the number of possible
408
--      good things must be smaller than (length badlist), because (possible good + bad == N), so regardless of the
409
--      count of the interval (MemberSpec (filter elements (`notElem` badlist))) is better. Sometimes much better.
410
--      Example, let 'n' be the finite set {0,1,2,3,4,5,6,7,8,9} and the bad list be [0,1,3,4,5,6,8,9]
411
--      (TypeSpec [0..9]  [0,1,3,4,5,6,8,9]) = filter  {0,1,2,3,4,5,6,7,8,9} (`notElem` [0,1,3,4,5,6,8,9]) = [2,7]
412
--      So (MemberSpec [2,7]) is better than  (TypeSpec [0..9]  [0,1,3,4,5,6,8,9]). This works no matter what
413
--      the count of interval is. We only need the (length badlist > (N/2)).
414
notInNumSpec ::
415
  forall n.
416
  ( HasSpec n
417
  , TypeSpec n ~ NumSpec n
418
  , Bounded n
419
  , Integral n
420
  ) =>
421
  NumSpec n ->
422
  [n] ->
423
  Specification n
424
notInNumSpec ns@(NumSpecInterval a b) bad
2✔
425
  | toInteger (length bad) > (finiteSize @n `div` 2) || countSpec ns < toInteger (length bad) =
1✔
UNCOV
426
      nubOrdMemberSpec
×
427
        ("call to: (notInNumSpec " ++ show ns ++ " " ++ show bad ++ ")")
×
428
        [x | x <- [lowBound a .. highBound b], notElem x bad]
×
429
  | otherwise = TypeSpec @n ns bad
1✔
430

431
-- ==========================================================================
432
-- Num n => (NumSpec n) can support operation of Num as interval arithmetic.
433
-- So we will make a (Num (NumSpec Integer)) instance. We won't make other
434
-- instances, because  they would be subject to overflow.
435
-- Given operator ☉, then (a,b) ☉ (c,d) = (minimum s, maximum s) where s = [a ☉ c, a ☉ d, b ☉ c, b ☉ d]
436
-- There are simpler rules for (+) and (-), but for (*) we need to use the general rule.
437
-- ==========================================================================
438

439
guardEmpty :: (Ord n, Num n) => Maybe n -> Maybe n -> NumSpec n -> NumSpec n
440
guardEmpty (Just a) (Just b) s
2✔
441
  | a <= b = s
2✔
442
  | otherwise = NumSpecInterval (Just 1) (Just 0)
1✔
443
guardEmpty _ _ s = s
2✔
444

445
addNumSpec :: (Ord n, Num n) => NumSpec n -> NumSpec n -> NumSpec n
446
addNumSpec (NumSpecInterval x y) (NumSpecInterval a b) =
2✔
447
  guardEmpty x y $
2✔
448
    guardEmpty a b $
2✔
449
      NumSpecInterval ((+) <$> x <*> a) ((+) <$> y <*> b)
2✔
450

451
subNumSpec :: (Ord n, Num n) => NumSpec n -> NumSpec n -> NumSpec n
452
subNumSpec (NumSpecInterval x y) (NumSpecInterval a b) =
2✔
453
  guardEmpty x y $
2✔
454
    guardEmpty a b $
2✔
455
      NumSpecInterval ((-) <$> x <*> b) ((-) <$> y <*> a)
2✔
456

457
multNumSpec :: (Ord n, Num n) => NumSpec n -> NumSpec n -> NumSpec n
458
multNumSpec (NumSpecInterval a b) (NumSpecInterval c d) =
2✔
459
  guardEmpty a b $
2✔
460
    guardEmpty c d $
2✔
461
      NumSpecInterval (unT (minimum s)) (unT (maximum s))
2✔
462
  where
463
    s = [multT (neg a) (neg c), multT (neg a) (pos d), multT (pos b) (neg c), multT (pos b) (pos d)]
2✔
464

465
negNumSpec :: Num n => NumSpec n -> NumSpec n
466
negNumSpec (NumSpecInterval lo hi) = NumSpecInterval (negate <$> hi) (negate <$> lo)
2✔
467

468
instance Num (NumSpec Integer) where
469
  (+) = addNumSpec
2✔
470
  (-) = subNumSpec
2✔
471
  (*) = multNumSpec
2✔
472
  negate = negNumSpec
2✔
473
  fromInteger n = NumSpecInterval (Just (fromInteger n)) (Just (fromInteger n))
2✔
UNCOV
474
  abs = error "No abs in the Num (NumSpec  Integer) instance"
×
475
  signum = error "No signum in the Num (NumSpec  Integer) instance"
×
476

477
-- ========================================================================
478
-- Helper functions for interval multiplication
479
--  (a,b) * (c,d) = (minimum s, maximum s) where s = [a * c, a * d, b * c, b * d]
480

481
-- | T is a sort of special version of Maybe, with two Nothings.
482
--   Given:: NumSpecInterval (Maybe n) (Maybe n) -> Numspec
483
--   We can't distinguish between the two Nothings in (NumSpecInterval Nothing Nothing)
484
--   But using (NumSpecInterval NegInf PosInf) we can, In fact we can make a total ordering on 'T'
485
--   So an ascending Sorted [T x] would all the NegInf on the left and all the PosInf on the right, with
486
--   the Ok's sorted in between. I.e. [NegInf, NegInf, Ok 3, Ok 6, Ok 12, Pos Inf]
487
data T x = NegInf | Ok x | PosInf
UNCOV
488
  deriving (Show, Eq, Ord)
×
489

490
-- \| Conversion between (T x) and (Maybe x)
491
unT :: T x -> Maybe x
492
unT (Ok x) = Just x
2✔
493
unT _ = Nothing
2✔
494

495
-- | Use this on the lower bound. I.e. lo from pair (lo,hi)
496
neg :: Maybe x -> T x
497
neg Nothing = NegInf
2✔
498
neg (Just x) = Ok x
2✔
499

500
-- | Use this on the upper bound. I.e. hi from pair (lo,hi)
501
pos :: Maybe x -> T x
502
pos Nothing = PosInf
2✔
503
pos (Just x) = Ok x
2✔
504

505
-- | multiply two (T x), correctly handling the infinities NegInf and PosInf
506
multT :: Num x => T x -> T x -> T x
507
multT NegInf NegInf = PosInf
2✔
508
multT NegInf PosInf = NegInf
2✔
509
multT NegInf (Ok _) = NegInf
2✔
510
multT (Ok _) NegInf = NegInf
2✔
511
multT (Ok x) (Ok y) = Ok (x * y)
2✔
512
multT (Ok _) PosInf = PosInf
2✔
513
multT PosInf PosInf = PosInf
2✔
514
multT PosInf NegInf = NegInf
2✔
515
multT PosInf (Ok _) = PosInf
2✔
516

517
-- ========================================================================
518
-- We have
519
-- (1) Num Integer
520
-- (2) Num (NumSpec Integer)   And we need
521
-- (3) Num (Specification Integer)
522
-- We need this to implement the method cardinalTypeSpec of (HasSpec t).
523
-- cardinalTypeSpec :: HasSpec a => TypeSpec a -> Specification Integer
524
-- Basically for defining these two cases
525
-- cardinalTypeSpec (Cartesian x y) = (cardinality x) * (cardinality y)
526
-- cardinalTypeSpec (SumSpec leftspec rightspec) = (cardinality leftspec) + (cardinality rightspec)
527
-- So we define addSpecInt for (+)   and  multSpecInt for (*)
528

529
-- | What constraints we need to make HasSpec instance for a Haskell numeric type.
530
--   By abstracting over this, we can avoid making actual HasSpec instances until
531
--   all the requirements (HasSpec Bool, HasSpec(Sum a b)) have been met in
532
--   Constrained.TheKnot.
533
type Number n = (Num n, Enum n, TypeSpec n ~ NumSpec n, Num (NumSpec n), HasSpec n, Ord n)
534

535
-- | Addition on `Specification` for `Number`
536
addSpecInt ::
537
  Number n =>
538
  Specification n ->
539
  Specification n ->
540
  Specification n
541
addSpecInt x y = operateSpec " + " (+) (+) x y
1✔
542

543
subSpecInt ::
544
  Number n =>
545
  Specification n ->
546
  Specification n ->
547
  Specification n
548
subSpecInt x y = operateSpec " - " (-) (-) x y
1✔
549

550
multSpecInt ::
551
  Number n =>
552
  Specification n ->
553
  Specification n ->
554
  Specification n
UNCOV
555
multSpecInt x y = operateSpec " * " (*) (*) x y
×
556

557
-- | let 'n' be some numeric type, and 'f' and 'ft' be operations on 'n' and (TypeSpec n)
558
--   Then lift these operations from (TypeSpec n) to (Specification n)
559
--   Normally 'f' will be a (Num n) instance method (+,-,*) on n,
560
--   and 'ft' will be a a (Num (TypeSpec n)) instance method (+,-,*) on (TypeSpec n)
561
--   But this will work for any operations 'f' and 'ft' with the right types
562
operateSpec ::
563
  Number n =>
564
  String ->
565
  (n -> n -> n) ->
566
  (TypeSpec n -> TypeSpec n -> TypeSpec n) ->
567
  Specification n ->
568
  Specification n ->
569
  Specification n
570
operateSpec operator f ft (ExplainSpec es x) y = explainSpec es $ operateSpec operator f ft x y
1✔
UNCOV
571
operateSpec operator f ft x (ExplainSpec es y) = explainSpec es $ operateSpec operator f ft x y
×
572
operateSpec operator f ft x y = case (x, y) of
2✔
UNCOV
573
  (ErrorSpec xs, ErrorSpec ys) -> ErrorSpec (xs <> ys)
×
574
  (ErrorSpec xs, _) -> ErrorSpec xs
×
575
  (_, ErrorSpec ys) -> ErrorSpec ys
×
576
  (TrueSpec, _) -> TrueSpec
2✔
577
  (_, TrueSpec) -> TrueSpec
2✔
UNCOV
578
  (_, SuspendedSpec _ _) -> TrueSpec
×
579
  (SuspendedSpec _ _, _) -> TrueSpec
×
580
  (TypeSpec a bad1, TypeSpec b bad2) -> TypeSpec (ft a b) [f b1 b2 | b1 <- bad1, b2 <- bad2]
×
581
  (MemberSpec xs, MemberSpec ys) ->
582
    nubOrdMemberSpec
2✔
UNCOV
583
      (show x ++ operator ++ show y)
×
584
      [f x1 y1 | x1 <- NE.toList xs, y1 <- NE.toList ys]
2✔
585
  -- This block is all (MemberSpec{}, TypeSpec{}) with MemberSpec on the left
586
  (MemberSpec ys, TypeSpec (NumSpecInterval (Just i) (Just j)) bad) ->
UNCOV
587
    let xs = NE.toList ys
×
588
     in nubOrdMemberSpec
UNCOV
589
          (show x ++ operator ++ show y)
×
590
          [f x1 y1 | x1 <- xs, y1 <- [i .. j], not (elem y1 bad)]
×
591
  -- Somewhat loose spec here, but more accurate then TrueSpec, it is exact if 'xs' has one element (i.e. 'xs' = [i])
592
  (MemberSpec ys, TypeSpec (NumSpecInterval lo hi) bads) ->
593
    -- We use the specialized version of 'TypeSpec' 'typeSpecOpt'
594
    let xs = NE.toList ys
2✔
595
     in typeSpecOpt
596
          (NumSpecInterval (f (minimum xs) <$> lo) (f (maximum xs) <$> hi))
1✔
597
          [f x1 b | x1 <- xs, b <- bads]
1✔
598
  -- we flip the arguments, so we need to flip the functions as well
599
  (sleft, sright) -> operateSpec operator (\a b -> f b a) (\u v -> ft v u) sright sleft
1✔
600

601
-- | This is very liberal, since in lots of cases it returns TrueSpec.
602
--  for example all operations on SuspendedSpec, and certain
603
--  operations between TypeSpec and MemberSpec. Perhaps we should
604
--  remove it. Only the addSpec (+) and multSpec (*) methods are used.
605
--  But, it is kind of cool ...
606
--  In Fact we can use this to make Num(Specification n) instance for any 'n'.
607
--  But, only Integer is safe, because in all other types (+) and especially
608
--  (-) can lead to overflow or underflow failures.
UNCOV
609
instance Number Integer => Num (Specification Integer) where
×
610
  (+) = addSpecInt
2✔
UNCOV
611
  (-) = subSpecInt
×
612
  (*) = multSpecInt
×
613
  fromInteger n = TypeSpec (NumSpecInterval (Just n) (Just n)) []
×
614
  abs _ = TrueSpec
×
615
  signum _ = TrueSpec
×
616

617
-- ===========================================================================
618

619
-- | Put some (admittedly loose bounds) on the number of solutions that
620
--   'genFromTypeSpec' might return. For lots of types, there is no way to be very accurate.
621
--   Here we lift the HasSpec methods 'cardinalTrueSpec' and 'cardinalTypeSpec'
622
--   from (TypeSpec Integer) to (Specification Integer)
623
cardinality ::
624
  forall a. (Number Integer, HasSpec a) => Specification a -> Specification Integer
625
cardinality (ExplainSpec es s) = explainSpec es (cardinality s)
2✔
626
cardinality TrueSpec = cardinalTrueSpec @a
2✔
627
cardinality (MemberSpec es) = equalSpec (toInteger $ length (nub (NE.toList es)))
2✔
628
cardinality ErrorSpec {} = equalSpec 0
2✔
629
cardinality (TypeSpec s cant) =
630
  subSpecInt
2✔
631
    (cardinalTypeSpec @a s)
2✔
632
    (equalSpec (toInteger $ length (nub $ filter (\c -> conformsTo @a c s) cant)))
2✔
633
cardinality SuspendedSpec {} = cardinalTrueSpec @a
2✔
634

635
-- | A generic function to use as an instance for the HasSpec method
636
--   cardinalTypeSpec :: HasSpec a => TypeSpec a -> Specification Integer
637
--   for types 'n' such that (TypeSpec n ~ NumSpec n)
638
cardinalNumSpec ::
639
  forall n. (Integral n, MaybeBounded n, HasSpec n) => NumSpec n -> Specification Integer
640
cardinalNumSpec (NumSpecInterval (Just lo) (Just hi)) =
2✔
641
  if hi >= lo
1✔
642
    then equalSpec (toInteger hi - toInteger lo + 1)
2✔
UNCOV
643
    else equalSpec 0
×
644
cardinalNumSpec (NumSpecInterval Nothing (Just hi)) =
645
  case lowerBound @n of
2✔
646
    Just lo -> equalSpec (toInteger hi - toInteger lo)
2✔
UNCOV
647
    Nothing -> TrueSpec
×
648
cardinalNumSpec (NumSpecInterval (Just lo) Nothing) =
649
  case upperBound @n of
2✔
650
    Just hi -> equalSpec (toInteger hi - toInteger lo)
2✔
UNCOV
651
    Nothing -> TrueSpec
×
652
cardinalNumSpec (NumSpecInterval Nothing Nothing) = cardinalTrueSpec @n
2✔
653

654
-- ====================================================================
655
-- Now the operations on Numbers
656

657
-- | Everything we need to make the number operations make sense on a given type
658
class (Num a, HasSpec a, HasDivision a, OrdLike a) => NumLike a where
659
  subtractSpec :: a -> TypeSpec a -> Specification a
660
  default subtractSpec ::
661
    ( NumLike (SimpleRep a)
662
    , GenericRequires a
663
    ) =>
664
    a ->
665
    TypeSpec a ->
666
    Specification a
UNCOV
667
  subtractSpec a ts = fromSimpleRepSpec $ subtractSpec (toSimpleRep a) ts
×
668

669
  negateSpec :: TypeSpec a -> Specification a
670
  default negateSpec ::
671
    ( NumLike (SimpleRep a)
672
    , GenericRequires a
673
    ) =>
674
    TypeSpec a ->
675
    Specification a
UNCOV
676
  negateSpec = fromSimpleRepSpec . negateSpec @(SimpleRep a)
×
677

678
  safeSubtract :: a -> a -> Maybe a
679
  default safeSubtract ::
680
    (HasSimpleRep a, NumLike (SimpleRep a)) =>
681
    a ->
682
    a ->
683
    Maybe a
UNCOV
684
  safeSubtract a b = fromSimpleRep <$> safeSubtract @(SimpleRep a) (toSimpleRep a) (toSimpleRep b)
×
685

686
-- | Operations on numbers.
687
-- The reason there is no implementation of abs here is that you can't easily deal with abs
688
-- without specifications becoming very large. Consider the following example:
689
-- > constrained $ \ x -> [1000 <. abs_ x, abs_ x <. 1050]
690
-- The natural `Specification` here would be something like `(-1050, -1000) || (1000, 1050)`
691
-- - the disjoint union of two open, non-overlapping, intervals. However, this doesn't work
692
-- because number type-specs only support a single interval. You could fudge it in all sorts of ways
693
-- by using `chooseSpec` or by using the can't set (which would blow up to be 2000 elements large in this
694
-- case). In short, there is no _satisfactory_ solution here.
695
data IntW (as :: [Type]) b where
696
  AddW :: NumLike a => IntW '[a, a] a
697
  MultW :: NumLike a => IntW '[a, a] a
698
  NegateW :: NumLike a => IntW '[a] a
699
  SignumW :: NumLike a => IntW '[a] a
700

UNCOV
701
deriving instance Eq (IntW dom rng)
×
702

UNCOV
703
instance Show (IntW d r) where
×
704
  show AddW = "+"
2✔
705
  show NegateW = "negate_"
2✔
706
  show MultW = "*"
2✔
707
  show SignumW = "signum_"
2✔
708

709
instance Semantics IntW where
710
  semantics AddW = (+)
2✔
711
  semantics NegateW = negate
2✔
712
  semantics MultW = (*)
2✔
713
  semantics SignumW = signum
2✔
714

715
instance Syntax IntW where
2✔
716
  isInfix AddW = True
2✔
UNCOV
717
  isInfix NegateW = False
×
718
  isInfix MultW = True
×
719
  isInfix SignumW = False
×
720

721
class HasDivision a where
722
  doDivide :: a -> a -> a
723
  default doDivide ::
724
    ( HasDivision (SimpleRep a)
725
    , GenericRequires a
726
    ) =>
727
    a ->
728
    a ->
729
    a
UNCOV
730
  doDivide a b = fromSimpleRep $ doDivide (toSimpleRep a) (toSimpleRep b)
×
731

732
  divideSpec :: a -> TypeSpec a -> Specification a
733
  default divideSpec ::
734
    ( HasDivision (SimpleRep a)
735
    , GenericRequires a
736
    ) =>
737
    a ->
738
    TypeSpec a ->
739
    Specification a
UNCOV
740
  divideSpec a ts = fromSimpleRepSpec $ divideSpec (toSimpleRep a) ts
×
741

742
instance {-# OVERLAPPABLE #-} (HasSpec a, MaybeBounded a, Integral a, TypeSpec a ~ NumSpec a) => HasDivision a where
743
  doDivide = div
2✔
744

745
  divideSpec 0 _ = TrueSpec
1✔
746
  divideSpec a (NumSpecInterval (unionWithMaybe max lowerBound -> ml) (unionWithMaybe min upperBound -> mu)) = typeSpec ts
2✔
747
    where
748
      ts | a > 0 = NumSpecInterval ml' mu'
2✔
749
         | otherwise = NumSpecInterval mu' ml'
1✔
750
      ml' = adjustLowerBound <$> ml
2✔
751
      mu' = adjustUpperBound <$> mu
2✔
752

753
      -- NOTE: negate has different overflow semantics than div, so that's why we use negate below...
754

755
      adjustLowerBound l
2✔
756
        | a == 1 = l
2✔
757
        | a == -1 = negate l
2✔
UNCOV
758
        | otherwise =
×
759
          let r = l `div` a in
2✔
760
          if toInteger r * toInteger a < toInteger l
2✔
761
          then r + signum a
2✔
762
          else r
2✔
763

764
      adjustUpperBound u
2✔
765
        | a == 1  = u
2✔
766
        | a == -1 = negate u
2✔
UNCOV
767
        | otherwise =
×
768
          let r = u `div` a in
2✔
769
          if toInteger r * toInteger a > toInteger u
2✔
770
          then r - signum a
2✔
771
          else r
2✔
772

773
instance HasDivision (Ratio Integer) where
774
  doDivide = (/)
2✔
775

776
  divideSpec 0 _ = TrueSpec
1✔
777
  divideSpec a (NumSpecInterval ml mu) = typeSpec ts
2✔
778
    where
779
      ts | a > 0 = NumSpecInterval ml' mu'
1✔
UNCOV
780
         | otherwise = NumSpecInterval mu' ml'
×
781
      ml' = adjustLowerBound <$> ml
2✔
782
      mu' = adjustUpperBound <$> mu
1✔
783
      adjustLowerBound l =
2✔
784
        let r = l / a
2✔
785
            l' = r * a
2✔
786
        in
787
        if l' < l
1✔
UNCOV
788
        then r + (l - l') * 2 / a
×
789
        else r
2✔
790

UNCOV
791
      adjustUpperBound u =
×
792
        let r = u / a
×
793
            u' = r * a
×
794
        in
UNCOV
795
        if u < u'
×
796
        then r - (u' - u) * 2 / a
×
797
        else r
×
798

799

800
instance HasDivision Float where
801
  doDivide = (/)
2✔
802

803
  divideSpec 0 _ = TrueSpec
1✔
804
  divideSpec a (NumSpecInterval ml mu) = typeSpec ts
2✔
805
    where
806
      ts | a > 0 = NumSpecInterval ml' mu'
2✔
807
         | otherwise = NumSpecInterval mu' ml'
1✔
808
      ml' = adjustLowerBound <$> ml
2✔
809
      mu' = adjustUpperBound <$> mu
2✔
810
      adjustLowerBound l =
2✔
811
        let r = l / a
2✔
812
            l' = r * a
2✔
813
        in
814
        if l' < l
2✔
815
        then r + (l - l') * 2 / a
2✔
816
        else r
2✔
817

818
      adjustUpperBound u =
2✔
819
        let r = u / a
2✔
820
            u' = r * a
2✔
821
        in
822
        if u < u'
2✔
823
        then r - (u' - u) * 2 / a
2✔
824
        else r
2✔
825

826
instance HasDivision Double where
827
  doDivide = (/)
2✔
828

829
  divideSpec 0 _ = TrueSpec
1✔
830
  divideSpec a (NumSpecInterval ml mu) = typeSpec ts
2✔
831
    where
832
      ts | a > 0 = NumSpecInterval ml' mu'
2✔
833
         | otherwise = NumSpecInterval mu' ml'
1✔
834
      ml' = adjustLowerBound <$> ml
2✔
835
      mu' = adjustUpperBound <$> mu
2✔
836
      adjustLowerBound l =
2✔
837
        let r = l / a
2✔
838
            l' = r * a
2✔
839
        in
840
        if l' < l
2✔
841
        then r + (l - l') * 2 / a
2✔
842
        else r
2✔
843

844
      adjustUpperBound u =
2✔
845
        let r = u / a
2✔
846
            u' = r * a
2✔
847
        in
848
        if u < u'
2✔
849
        then r - (u' - u) * 2 / a
2✔
850
        else r
2✔
851

852
-- | A type that we can reason numerically about in constraints
853
type Numeric a = (HasSpec a, Ord a, Num a, TypeSpec a ~ NumSpec a, MaybeBounded a, HasDivision a)
854

855
instance {-# OVERLAPPABLE #-} Numeric a => NumLike a where
856
  subtractSpec a ts@(NumSpecInterval ml mu)
2✔
857
    | Just u <- mu
2✔
858
    , a > 0
2✔
859
    , Nothing <- safeSubtract a u =
2✔
860
        ErrorSpec $
2✔
UNCOV
861
          NE.fromList
×
862
            [ "Underflow in subtractSpec (" ++ showType @a ++ "):"
×
863
            , "  a = " ++ show a
×
864
            , "  ts = " ++ show ts
×
865
            ]
866
    | Just l <- ml
2✔
867
    , a < 0
2✔
868
    , Nothing <- safeSubtract a l =
2✔
869
        ErrorSpec $
2✔
UNCOV
870
          NE.fromList
×
871
            [ "Overflow in subtractSpec (" ++ showType @a ++ "):"
×
872
            , "  a = " ++ show a
×
873
            , "  ts = " ++ show ts
×
874
            ]
875
    | otherwise = typeSpec $ NumSpecInterval (safeSub a <$> ml) (safeSub a <$> mu)
1✔
876
    where
877
      safeSub :: a -> a -> a
878
      safeSub a1 x
2✔
879
        | Just r <- safeSubtract a1 x = r
2✔
880
        | a1 < 0 = fromJust upperBound
2✔
881
        | otherwise = fromJust lowerBound
1✔
882

883
  negateSpec (NumSpecInterval ml mu) = typeSpec $ NumSpecInterval (negate <$> mu) (negate <$> ml)
2✔
884

885
  safeSubtract a x
2✔
886
    | a > 0
2✔
887
    , Just lb <- lowerBound
2✔
888
    , lb + a > x =
2✔
889
        Nothing
2✔
890
    | a < 0
2✔
891
    , Just ub <- upperBound
2✔
892
    , ub + a < x =
2✔
893
        Nothing
2✔
894
    | otherwise = Just $ x - a
1✔
895

896
instance NumLike a => Num (Term a) where
2✔
897
  (+) = (+.)
2✔
898
  negate = negate_
2✔
899
  fromInteger = Lit . fromInteger
2✔
900
  (*) = (*.)
2✔
901
  signum = signum_
2✔
UNCOV
902
  abs = error "No implementation for abs @(Term a)"
×
903

904
invertMult :: (HasSpec a, Num a, HasDivision a) => a -> a -> Maybe a
905
invertMult a b =
2✔
906
  let r = a `doDivide` b in if r * b == a then Just r else Nothing
2✔
907

908
-- | Just a note that these instances won't work until we are in a context where
909
--   there is a HasSpec instance of 'a', which (NumLike a) demands.
910
--   This happens in Constrained.Experiment.TheKnot
911
instance Logic IntW where
1✔
912
  propagateTypeSpec AddW (HOLE :<: i) ts cant = subtractSpec i ts <> notMemberSpec (mapMaybe (safeSubtract i) cant)
2✔
913
  propagateTypeSpec AddW ctx ts cant = propagateTypeSpec AddW (flipCtx ctx) ts cant
2✔
914
  propagateTypeSpec NegateW (Unary HOLE) ts cant = negateSpec ts <> notMemberSpec (map negate cant)
2✔
915
  propagateTypeSpec MultW (HOLE :<: 0) ts cant
916
    | 0 `conformsToSpec` TypeSpec ts cant = TrueSpec
2✔
917
    | otherwise = ErrorSpec $ NE.fromList [ "zero" ]
1✔
918
  propagateTypeSpec MultW (HOLE :<: i) ts cant = divideSpec i ts <> notMemberSpec (mapMaybe (flip invertMult i) cant)
2✔
919
  propagateTypeSpec MultW ctx ts cant = propagateTypeSpec MultW (flipCtx ctx) ts cant
2✔
920
  propagateTypeSpec SignumW (Unary HOLE) ts cant =
921
    constrained $ \ x ->
2✔
922
      [ x `satisfies` notMemberSpec [0] | not $ ok 0 ] ++
2✔
923
      [ Assert $ 0 <=. x                | not $ ok (-1) ] ++
2✔
924
      [ Assert $ x <=. 0                | not $ ok 1 ]
2✔
925
    where ok = flip conformsToSpec (TypeSpec ts cant)
2✔
926

927
  propagateMemberSpec AddW (HOLE :<: i) es =
2✔
928
    memberSpec
2✔
929
      (nubOrd $ mapMaybe (safeSubtract i) (NE.toList es))
2✔
UNCOV
930
      ( NE.fromList
×
931
          [ "propagateSpecFn on (" ++ show i ++ " +. HOLE)"
×
932
          , "The Spec is a MemberSpec = " ++ show es -- show (MemberSpec @HasSpec @TS es)
×
933
          , "We can't safely subtract " ++ show i ++ " from any choice in the MemberSpec."
×
934
          ]
935
      )
936
  propagateMemberSpec AddW ctx es = propagateMemberSpec AddW (flipCtx ctx) es
2✔
937
  propagateMemberSpec NegateW (Unary HOLE) es = MemberSpec $ NE.nub $ fmap negate es
2✔
938
  propagateMemberSpec MultW (HOLE :<: 0) es
939
    | 0 `elem` es = TrueSpec
2✔
940
    | otherwise = ErrorSpec $ NE.fromList [ "zero" ]
1✔
941
  propagateMemberSpec MultW (HOLE :<: i) es = memberSpec (mapMaybe (flip invertMult i) (NE.toList es)) (NE.fromList ["propagateSpec"])
1✔
942
  propagateMemberSpec MultW ctx es = propagateMemberSpec MultW (flipCtx ctx) es
2✔
943
  propagateMemberSpec SignumW (Unary HOLE) es
944
    | all ((`notElem` [-1, 0, 1]) . signum) es = ErrorSpec $ NE.fromList [ "signum for invalid member spec", show es ]
1✔
945
    | otherwise = constrained $ \ x ->
1✔
946
                    [ x `satisfies` notMemberSpec [0] | 0  `notElem` es ] ++
2✔
947
                    [ Assert $ 0 <=. x                | -1 `notElem` es ] ++
2✔
948
                    [ Assert $ x <=. 0                | 1  `notElem` es ]
2✔
949

950
  rewriteRules AddW (x :> y :> Nil) _ | x == y = Just $ 2 * x
2✔
951
  rewriteRules _ _ _ = Nothing
2✔
952

953
infix 4 +.
954

955
-- | `Term`-level `(+)`
956
(+.) :: NumLike a => Term a -> Term a -> Term a
957
(+.) = appTerm AddW
2✔
958

959
infixl 7 *.
960

961
-- | `Term`-level `(+)`
962
(*.) :: NumLike a => Term a -> Term a -> Term a
963
(*.) = appTerm MultW
2✔
964

965
-- | `Term`-level `negate`
966
negate_ :: NumLike a => Term a -> Term a
967
negate_ = appTerm NegateW
2✔
968

969
-- | `Term`-level `signum`
970
signum_ :: NumLike a => Term a -> Term a
971
signum_ = appTerm SignumW
2✔
972

973
infix 4 -.
974

975
-- | `Term`-level `(-)`
976
(-.) :: Numeric n => Term n -> Term n -> Term n
UNCOV
977
(-.) x y = x +. negate_ y
×
978

979
infixr 4 <=.
980

981
-- | `Term`-level `(<=)`
982
(<=.) :: forall a. OrdLike a => Term a -> Term a -> Term Bool
983
(<=.) = appTerm LessOrEqualW
2✔
984

985
infixr 4 <.
986

987
-- | `Term`-level `(<)`
988
(<.) :: forall a. OrdLike a => Term a -> Term a -> Term Bool
989
(<.) = appTerm LessW
2✔
990

991
infixr 4 >=.
992

993
-- | `Term`-level `(>=)`
994
(>=.) :: forall a. OrdLike a => Term a -> Term a -> Term Bool
995
(>=.) = appTerm GreaterOrEqualW
2✔
996

997
infixr 4 >.
998

999
-- | `Term`-level `(>)`
1000
(>.) :: forall a. OrdLike a => Term a -> Term a -> Term Bool
1001
(>.) = appTerm GreaterW
2✔
1002

1003
-- | t`TypeSpec`-level `satisfies` to implement `toPreds` in
1004
-- `HasSpec` instance
1005
toPredsNumSpec ::
1006
  OrdLike n =>
1007
  Term n ->
1008
  NumSpec n ->
1009
  Pred
1010
toPredsNumSpec v (NumSpecInterval ml mu) =
2✔
1011
  fold $
2✔
1012
    [Assert $ Lit l <=. v | l <- maybeToList ml]
2✔
1013
      ++ [Assert $ v <=. Lit u | u <- maybeToList mu]
2✔
1014

UNCOV
1015
instance Logic OrdW where
×
1016
  propagate f ctxt (ExplainSpec [] s) = propagate f ctxt s
1✔
1017
  propagate f ctxt (ExplainSpec es s) = ExplainSpec es $ propagate f ctxt s
2✔
1018
  propagate _ _ TrueSpec = TrueSpec
2✔
1019
  propagate _ _ (ErrorSpec msgs) = ErrorSpec msgs
1✔
1020
  propagate GreaterW (HOLE :? x :> Nil) spec =
1021
    propagate LessW (x :! Unary HOLE) spec
2✔
1022
  propagate GreaterW (x :! Unary HOLE) spec =
1023
    propagate LessW (HOLE :? x :> Nil) spec
2✔
1024
  propagate LessOrEqualW (HOLE :? Value x :> Nil) (SuspendedSpec v ps) =
1025
    constrained $ \v' -> Let (App LessOrEqualW (v' :> Lit x :> Nil)) (v :-> ps)
2✔
1026
  propagate LessOrEqualW (Value x :! Unary HOLE) (SuspendedSpec v ps) =
1027
    constrained $ \v' -> Let (App LessOrEqualW (Lit x :> v' :> Nil)) (v :-> ps)
2✔
1028
  propagate LessOrEqualW (HOLE :? Value l :> Nil) spec =
1029
    caseBoolSpec spec $ \case True -> leqSpec l; False -> gtSpec l
2✔
1030
  propagate LessOrEqualW (Value l :! Unary HOLE) spec =
1031
    caseBoolSpec spec $ \case True -> geqSpec l; False -> ltSpec l
2✔
1032
  propagate GreaterOrEqualW (HOLE :? Value x :> Nil) spec =
1033
    propagate LessOrEqualW (Value x :! Unary HOLE) spec
2✔
1034
  propagate GreaterOrEqualW (x :! Unary HOLE) spec =
UNCOV
1035
    propagate LessOrEqualW (HOLE :? x :> Nil) spec
×
1036
  propagate LessW (HOLE :? Value x :> Nil) (SuspendedSpec v ps) =
1037
    constrained $ \v' -> Let (App LessW (v' :> Lit x :> Nil)) (v :-> ps)
2✔
1038
  propagate LessW (Value x :! Unary HOLE) (SuspendedSpec v ps) =
1039
    constrained $ \v' -> Let (App LessW (Lit x :> v' :> Nil)) (v :-> ps)
2✔
1040
  propagate LessW (HOLE :? Value l :> Nil) spec =
1041
    caseBoolSpec spec $ \case True -> ltSpec l; False -> geqSpec l
2✔
1042
  propagate LessW (Value l :! Unary HOLE) spec =
1043
    caseBoolSpec spec $ \case True -> gtSpec l; False -> leqSpec l
2✔
1044

1045
-- | @if-then-else@ on a specification, useful for writing `propagate` implementations
1046
-- of predicates, e.g.:
1047
-- > propagate LessW (Value l :! Unary HOLE) spec =
1048
-- >   caseBoolSpec spec $ \case True -> gtSpec l; False -> leqSpec l
1049
caseBoolSpec ::
1050
  HasSpec a => Specification Bool -> (Bool -> Specification a) -> Specification a
1051
caseBoolSpec spec cont = case possibleValues spec of
2✔
1052
  [] -> ErrorSpec (NE.fromList ["No possible values in caseBoolSpec"])
1✔
1053
  [b] -> cont b
2✔
1054
  _ -> mempty
2✔
1055
  where
1056
    -- This will always get the same result, and probably faster since running 2
1057
    -- conformsToSpec on True and False takes less time than simplifying the spec.
1058
    -- Since we are in TheKnot, we could keep the simplifySpec. Is there a good reason to?
1059
    possibleValues s = filter (flip conformsToSpec s) [True, False]
2✔
1060

1061
------------------------------------------------------------------------
1062
-- Instances of HasSpec for numeric types
1063
------------------------------------------------------------------------
1064

UNCOV
1065
instance HasSpec Integer where
×
1066
  type TypeSpec Integer = NumSpec Integer
1067
  emptySpec = emptyNumSpec
2✔
1068
  combineSpec = combineNumSpec
2✔
1069
  genFromTypeSpec = genFromNumSpec
2✔
1070
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1071
  fixupWithTypeSpec = fixupWithNumSpec
×
1072
  conformsTo = conformsToNumSpec
2✔
1073
  toPreds = toPredsNumSpec
2✔
UNCOV
1074
  cardinalTypeSpec = cardinalNumSpec
×
1075
  guardTypeSpec = guardNumSpec
2✔
1076

UNCOV
1077
instance HasSpec Int where
×
1078
  type TypeSpec Int = NumSpec Int
1079
  emptySpec = emptyNumSpec
2✔
1080
  combineSpec = combineNumSpec
2✔
1081
  genFromTypeSpec = genFromNumSpec
2✔
1082
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
1083
  fixupWithTypeSpec = fixupWithNumSpec
2✔
1084
  conformsTo = conformsToNumSpec
2✔
1085
  toPreds = toPredsNumSpec
2✔
1086
  cardinalTypeSpec = cardinalNumSpec
2✔
1087
  guardTypeSpec = guardNumSpec
2✔
1088

UNCOV
1089
instance HasSpec (Ratio Integer) where
×
1090
  type TypeSpec (Ratio Integer) = NumSpec (Ratio Integer)
1091
  emptySpec = emptyNumSpec
2✔
1092
  combineSpec = combineNumSpec
2✔
1093
  genFromTypeSpec = genFromNumSpec
2✔
1094
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1095
  fixupWithTypeSpec = fixupWithNumSpec
×
1096
  conformsTo = conformsToNumSpec
2✔
1097
  toPreds = toPredsNumSpec
2✔
UNCOV
1098
  cardinalTypeSpec _ = TrueSpec
×
1099
  guardTypeSpec = guardNumSpec
2✔
1100

UNCOV
1101
instance HasSpec Natural where
×
1102
  type TypeSpec Natural = NumSpec Natural
1103
  emptySpec = emptyNumSpec
2✔
1104
  combineSpec = combineNumSpec
2✔
1105
  genFromTypeSpec = genFromNumSpec
2✔
1106
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1107
  fixupWithTypeSpec = fixupWithNumSpec
×
1108
  conformsTo = conformsToNumSpec
2✔
UNCOV
1109
  toPreds = toPredsNumSpec
×
1110
  cardinalTypeSpec (NumSpecInterval (fromMaybe 0 -> lo) (Just hi)) =
×
1111
    if lo < hi
×
1112
      then equalSpec (fromIntegral $ hi - lo + 1)
×
1113
      else equalSpec 0
×
1114
  cardinalTypeSpec _ = TrueSpec
×
1115
  guardTypeSpec = guardNumSpec
2✔
1116

UNCOV
1117
instance HasSpec Word8 where
×
1118
  type TypeSpec Word8 = NumSpec Word8
1119
  emptySpec = emptyNumSpec
2✔
1120
  combineSpec = combineNumSpec
2✔
1121
  genFromTypeSpec = genFromNumSpec
2✔
1122
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1123
  fixupWithTypeSpec = fixupWithNumSpec
×
1124
  conformsTo = conformsToNumSpec
2✔
1125
  toPreds = toPredsNumSpec
2✔
UNCOV
1126
  cardinalTypeSpec = cardinalNumSpec
×
1127
  cardinalTrueSpec = equalSpec 256
×
1128
  typeSpecOpt = notInNumSpec
2✔
1129
  guardTypeSpec = guardNumSpec
2✔
1130

UNCOV
1131
instance HasSpec Word16 where
×
1132
  type TypeSpec Word16 = NumSpec Word16
1133
  emptySpec = emptyNumSpec
2✔
1134
  combineSpec = combineNumSpec
2✔
1135
  genFromTypeSpec = genFromNumSpec
2✔
1136
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1137
  fixupWithTypeSpec = fixupWithNumSpec
×
1138
  conformsTo = conformsToNumSpec
2✔
UNCOV
1139
  toPreds = toPredsNumSpec
×
1140
  cardinalTypeSpec = cardinalNumSpec
×
1141
  cardinalTrueSpec = equalSpec 65536
×
1142
  guardTypeSpec = guardNumSpec
2✔
1143

UNCOV
1144
instance HasSpec Word32 where
×
1145
  type TypeSpec Word32 = NumSpec Word32
1146
  emptySpec = emptyNumSpec
2✔
1147
  combineSpec = combineNumSpec
2✔
1148
  genFromTypeSpec = genFromNumSpec
2✔
1149
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1150
  fixupWithTypeSpec = fixupWithNumSpec
×
1151
  conformsTo = conformsToNumSpec
2✔
UNCOV
1152
  toPreds = toPredsNumSpec
×
1153
  cardinalTypeSpec = cardinalNumSpec
×
1154
  guardTypeSpec = guardNumSpec
2✔
1155

UNCOV
1156
instance HasSpec Word64 where
×
1157
  type TypeSpec Word64 = NumSpec Word64
1158
  emptySpec = emptyNumSpec
2✔
1159
  combineSpec = combineNumSpec
2✔
1160
  genFromTypeSpec = genFromNumSpec
2✔
1161
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1162
  fixupWithTypeSpec = fixupWithNumSpec
×
1163
  conformsTo = conformsToNumSpec
2✔
1164
  toPreds = toPredsNumSpec
2✔
1165
  cardinalTypeSpec = cardinalNumSpec
2✔
1166
  guardTypeSpec = guardNumSpec
2✔
1167

UNCOV
1168
instance HasSpec Int8 where
×
1169
  type TypeSpec Int8 = NumSpec Int8
1170
  emptySpec = emptyNumSpec
2✔
1171
  combineSpec = combineNumSpec
2✔
1172
  genFromTypeSpec = genFromNumSpec
2✔
1173
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1174
  fixupWithTypeSpec = fixupWithNumSpec
×
1175
  conformsTo = conformsToNumSpec
2✔
1176
  toPreds = toPredsNumSpec
2✔
UNCOV
1177
  cardinalTrueSpec = equalSpec 256
×
1178
  cardinalTypeSpec = cardinalNumSpec
×
1179
  guardTypeSpec = guardNumSpec
2✔
1180

UNCOV
1181
instance HasSpec Int16 where
×
1182
  type TypeSpec Int16 = NumSpec Int16
1183
  emptySpec = emptyNumSpec
2✔
1184
  combineSpec = combineNumSpec
2✔
1185
  genFromTypeSpec = genFromNumSpec
2✔
1186
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1187
  fixupWithTypeSpec = fixupWithNumSpec
×
1188
  conformsTo = conformsToNumSpec
2✔
UNCOV
1189
  toPreds = toPredsNumSpec
×
1190
  cardinalTypeSpec = cardinalNumSpec
×
1191
  cardinalTrueSpec = equalSpec 65536
×
1192
  guardTypeSpec = guardNumSpec
2✔
1193

UNCOV
1194
instance HasSpec Int32 where
×
1195
  type TypeSpec Int32 = NumSpec Int32
1196
  emptySpec = emptyNumSpec
2✔
1197
  combineSpec = combineNumSpec
2✔
1198
  genFromTypeSpec = genFromNumSpec
2✔
1199
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1200
  fixupWithTypeSpec = fixupWithNumSpec
×
1201
  conformsTo = conformsToNumSpec
2✔
UNCOV
1202
  toPreds = toPredsNumSpec
×
1203
  cardinalTypeSpec = cardinalNumSpec
×
1204
  guardTypeSpec = guardNumSpec
2✔
1205

UNCOV
1206
instance HasSpec Int64 where
×
1207
  type TypeSpec Int64 = NumSpec Int64
1208
  emptySpec = emptyNumSpec
2✔
1209
  combineSpec = combineNumSpec
2✔
1210
  genFromTypeSpec = genFromNumSpec
2✔
1211
  shrinkWithTypeSpec = shrinkWithNumSpec
2✔
UNCOV
1212
  fixupWithTypeSpec = fixupWithNumSpec
×
1213
  conformsTo = conformsToNumSpec
2✔
UNCOV
1214
  toPreds = toPredsNumSpec
×
1215
  cardinalTypeSpec = cardinalNumSpec
×
1216
  guardTypeSpec = guardNumSpec
2✔
1217

UNCOV
1218
instance HasSpec Float where
×
1219
  type TypeSpec Float = NumSpec Float
1220
  emptySpec = emptyNumSpec
2✔
1221
  combineSpec = combineNumSpec
2✔
1222
  genFromTypeSpec = genFromNumSpec
2✔
UNCOV
1223
  shrinkWithTypeSpec = shrinkWithNumSpec
×
1224
  fixupWithTypeSpec = fixupWithNumSpec
×
1225
  conformsTo = conformsToNumSpec
2✔
1226
  toPreds = toPredsNumSpec
2✔
UNCOV
1227
  cardinalTypeSpec _ = TrueSpec
×
1228
  guardTypeSpec = guardNumSpec
2✔
1229

UNCOV
1230
instance HasSpec Double where
×
1231
  type TypeSpec Double = NumSpec Double
1232
  emptySpec = emptyNumSpec
2✔
1233
  combineSpec = combineNumSpec
2✔
1234
  genFromTypeSpec = genFromNumSpec
2✔
UNCOV
1235
  shrinkWithTypeSpec = shrinkWithNumSpec
×
1236
  fixupWithTypeSpec = fixupWithNumSpec
×
1237
  conformsTo = conformsToNumSpec
2✔
1238
  toPreds = toPredsNumSpec
2✔
UNCOV
1239
  cardinalTypeSpec _ = TrueSpec
×
1240
  guardTypeSpec = guardNumSpec
2✔
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