Grisette.Internal.Core.Data.Class.PlainUnion

Documentation

class (Applicative u, SymBranching u) => PlainUnion (u :: Type -> Type) where

Plain union containers that can be projected back into single value or if-guarded values.

Minimal complete definition

singleView, ifView

Methods

singleView :: u a -> Maybe a

Pattern match to extract single values.

>>> singleView (return 1 :: Union Integer)
Just 1
>>> singleView (mrgIfPropagatedStrategy "a" (return 1) (return 2) :: Union Integer)
Nothing

ifView :: u a -> Maybe (SymBool, u a, u a)

Pattern match to extract if values.

>>> ifView (return 1 :: Union Integer)
Nothing
>>> ifView (mrgIfPropagatedStrategy "a" (return 1) (return 2) :: Union Integer)
Just (a,<1>,<2>)
>>> ifView (mrgIf "a" (return 1) (return 2) :: Union Integer)
Just (a,{1},{2})

toGuardedList :: u a -> [(SymBool, a)]

Convert the union to a guarded list.

>>> toGuardedList (mrgIf "a" (return 1) (mrgIf "b" (return 2) (return 3)) :: Union Integer)
[(a,1),((&& b (! a)),2),((! (|| b a)),3)]

overestimateUnionValues :: Mergeable a => u a -> [a]

Return all possible values in the union. Drop the path conditions.

>>> overestimateUnionValues (return 1 :: Union Integer)
[1]

>>> overestimateUnionValues (mrgIf "a" (return 1) (return 2) :: Union Integer)
[1,2]

Instances

PlainUnion Union

Defined in Grisette.Internal.Core.Control.Monad.Union

Methods

singleView :: Union a -> Maybe a

ifView :: Union a -> Maybe (SymBool, Union a, Union a)

toGuardedList :: Union a -> [(SymBool, a)]

overestimateUnionValues :: Mergeable a => Union a -> [a]

PlainUnion UnionBase

Defined in Grisette.Internal.Core.Data.UnionBase

Methods

singleView :: UnionBase a -> Maybe a

ifView :: UnionBase a -> Maybe (SymBool, UnionBase a, UnionBase a)

toGuardedList :: UnionBase a -> [(SymBool, a)]

overestimateUnionValues :: Mergeable a => UnionBase a -> [a]

pattern Single :: (PlainUnion u, Mergeable a) => a -> u a

Pattern match to extract single values with singleView.

>>> case (return 1 :: Union Integer) of Single v -> v
1

pattern If :: (PlainUnion u, Mergeable a) => SymBool -> u a -> u a -> u a

Pattern match to extract guard values with ifView

>>> case (mrgIfPropagatedStrategy "a" (return 1) (return 2) :: Union Integer) of If c t f -> (c,t,f)
(a,<1>,<2>)

simpleMerge :: forall u a. (SimpleMergeable a, PlainUnion u) => u a -> a

Merge the simply mergeable values in a union, and extract the merged value.

In the following example, mrgIfPropagatedStrategy will not merge the results, and simpleMerge will merge it and extract the single merged value.

>>> mrgIfPropagatedStrategy (ssym "a") (return $ ssym "b") (return $ ssym "c") :: Union SymBool
<If a b c>
>>> simpleMerge $ (mrgIfPropagatedStrategy (ssym "a") (return $ ssym "b") (return $ ssym "c") :: Union SymBool)
(ite a b c)

symIteMerge :: (ITEOp a, Mergeable a, PlainUnion u) => u a -> a

Merge the mergeable values in a union, using symIte, and extract the merged value.

The reason why we provide this class is that for some types, we only have ITEOp (which may throw an error), and we don't have a SimpleMergeable instance. In this case, we can use symIteMerge to merge the values.

(.#) :: (Function f a r, SimpleMergeable r, PlainUnion u) => f -> u a -> r infixl 9

Helper for applying functions on PlainUnion and SimpleMergeable.

>>> let f :: Integer -> Union Integer = \x -> mrgIf (ssym "a") (mrgSingle $ x + 1) (mrgSingle $ x + 2)
>>> f .# (mrgIf (ssym "b" :: SymBool) (mrgSingle 0) (mrgSingle 2) :: Union Integer)
{If (&& b a) 1 (If b 2 (If a 3 4))}

onUnion :: forall u a r. (SimpleMergeable r, SymBranching u, PlainUnion u, Mergeable a) => (a -> r) -> u a -> r

Lift a function to work on union values.

>>> sumU = onUnion sum :: Union [SymInteger] -> SymInteger
>>> sumU (mrgIfPropagatedStrategy "cond" (return ["a"]) (return ["b","c"]) :: Union [SymInteger])
(ite cond a (+ b c))

onUnion2 :: forall u a b r. (SimpleMergeable r, SymBranching u, PlainUnion u, Mergeable a, Mergeable b) => (a -> b -> r) -> u a -> u b -> r

Lift a function to work on union values.

onUnion3 :: forall u a b c r. (SimpleMergeable r, SymBranching u, PlainUnion u, Mergeable a, Mergeable b, Mergeable c) => (a -> b -> c -> r) -> u a -> u b -> u c -> r

Lift a function to work on union values.

onUnion4 :: forall u a b c d r. (SimpleMergeable r, SymBranching u, PlainUnion u, Mergeable a, Mergeable b, Mergeable c, Mergeable d) => (a -> b -> c -> d -> r) -> u a -> u b -> u c -> u d -> r

Lift a function to work on union values.