Safe Haskell	Safe-Inferred
Language	Haskell2010

PlutusTx.Maybe

Synopsis

data Maybe a
- = Nothing
- | Just a
isJust ∷ Maybe a → Bool
isNothing ∷ Maybe a → Bool
maybe ∷ b → (a → b) → Maybe a → b
fromMaybe ∷ a → Maybe a → a
mapMaybe ∷ (a → Maybe b) → [a] → [b]

Documentation

data Maybe a Source #

The Maybe type encapsulates an optional value. A value of type Maybe a either contains a value of type a (represented as Just a), or it is empty (represented as Nothing). Using Maybe is a good way to deal with errors or exceptional cases without resorting to drastic measures such as error.

The Maybe type is also a monad. It is a simple kind of error monad, where all errors are represented by Nothing. A richer error monad can be built using the Either type.

Constructors

Nothing
Just a

Instances

Instances details

FromJSON1 Maybe
Instance details Defined in Data.Aeson.Types.FromJSON Methods liftParseJSON ∷ Maybe a → (Value → Parser a) → (Value → Parser [a]) → Value → Parser (Maybe a) liftParseJSONList ∷ Maybe a → (Value → Parser a) → (Value → Parser [a]) → Value → Parser [Maybe a] liftOmittedField ∷ Maybe a → Maybe (Maybe a)
ToJSON1 Maybe
Instance details Defined in Data.Aeson.Types.ToJSON Methods liftToJSON ∷ (a → Bool) → (a → Value) → ([a] → Value) → Maybe a → Value liftToJSONList ∷ (a → Bool) → (a → Value) → ([a] → Value) → [Maybe a] → Value liftToEncoding ∷ (a → Bool) → (a → Encoding) → ([a] → Encoding) → Maybe a → Encoding liftToEncodingList ∷ (a → Bool) → (a → Encoding) → ([a] → Encoding) → [Maybe a] → Encoding liftOmitField ∷ (a → Bool) → Maybe a → Bool
MonadFail Maybe	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fail Methods fail ∷ String → Maybe a Source #
Foldable Maybe	Since: base-2.1
Instance details Defined in Data.Foldable Methods fold ∷ Monoid m ⇒ Maybe m → m Source # foldMap ∷ Monoid m ⇒ (a → m) → Maybe a → m Source # foldMap' ∷ Monoid m ⇒ (a → m) → Maybe a → m Source # foldr ∷ (a → b → b) → b → Maybe a → b Source # foldr' ∷ (a → b → b) → b → Maybe a → b Source # foldl ∷ (b → a → b) → b → Maybe a → b Source # foldl' ∷ (b → a → b) → b → Maybe a → b Source # foldr1 ∷ (a → a → a) → Maybe a → a Source # foldl1 ∷ (a → a → a) → Maybe a → a Source # toList ∷ Maybe a → [a] Source # null ∷ Maybe a → Bool Source # length ∷ Maybe a → Int Source # elem ∷ Eq a ⇒ a → Maybe a → Bool Source # maximum ∷ Ord a ⇒ Maybe a → a Source # minimum ∷ Ord a ⇒ Maybe a → a Source # sum ∷ Num a ⇒ Maybe a → a Source # product ∷ Num a ⇒ Maybe a → a Source #
Traversable Maybe	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse ∷ Applicative f ⇒ (a → f b) → Maybe a → f (Maybe b) Source # sequenceA ∷ Applicative f ⇒ Maybe (f a) → f (Maybe a) Source # mapM ∷ Monad m ⇒ (a → m b) → Maybe a → m (Maybe b) Source # sequence ∷ Monad m ⇒ Maybe (m a) → m (Maybe a) Source #
Alternative Maybe	Picks the leftmost `Just` value, or, alternatively, `Nothing`. Since: base-2.1
Instance details Defined in GHC.Base Methods empty ∷ Maybe a Source # (<\|>) ∷ Maybe a → Maybe a → Maybe a Source # some ∷ Maybe a → Maybe [a] Source # many ∷ Maybe a → Maybe [a] Source #
Applicative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods pure ∷ a → Maybe a Source # (<>) ∷ Maybe (a → b) → Maybe a → Maybe b Source # liftA2 ∷ (a → b → c) → Maybe a → Maybe b → Maybe c Source # (>) ∷ Maybe a → Maybe b → Maybe b Source # (<*) ∷ Maybe a → Maybe b → Maybe a Source #
Functor Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap ∷ (a → b) → Maybe a → Maybe b Source # (<$) ∷ a → Maybe b → Maybe a Source #
Monad Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) ∷ Maybe a → (a → Maybe b) → Maybe b Source # (>>) ∷ Maybe a → Maybe b → Maybe b Source # return ∷ a → Maybe a Source #
MonadPlus Maybe	Picks the leftmost `Just` value, or, alternatively, `Nothing`. Since: base-2.1
Instance details Defined in GHC.Base Methods mzero ∷ Maybe a Source # mplus ∷ Maybe a → Maybe a → Maybe a Source #
MonadFailure Maybe
Instance details Defined in Basement.Monad Associated Types type Failure Maybe Methods mFail ∷ Failure Maybe → Maybe ()
NFData1 Maybe	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf ∷ (a → ()) → Maybe a → () Source #
Hashable1 Maybe
Instance details Defined in Data.Hashable.Class Methods liftHashWithSalt ∷ (Int → a → Int) → Int → Maybe a → Int Source #
Applicative Maybe Source #
Instance details Defined in PlutusTx.Applicative Methods pure ∷ a → Maybe a Source # (<*>) ∷ Maybe (a → b) → Maybe a → Maybe b Source #
Foldable Maybe Source #
Instance details Defined in PlutusTx.Foldable Methods foldr ∷ (a → b → b) → b → Maybe a → b Source #
Functor Maybe Source #
Instance details Defined in PlutusTx.Functor Methods fmap ∷ (a → b) → Maybe a → Maybe b Source #
Traversable Maybe Source #
Instance details Defined in PlutusTx.Traversable Methods traverse ∷ Applicative f ⇒ (a → f b) → Maybe a → f (Maybe b) Source #
Generic1 Maybe
Instance details Defined in GHC.Generics Associated Types type Rep1 Maybe ∷ k → Type Source # Methods from1 ∷ ∀ (a ∷ k). Maybe a → Rep1 Maybe a Source # to1 ∷ ∀ (a ∷ k). Rep1 Maybe a → Maybe a Source #
FoldableWithIndex () Maybe
Instance details Defined in WithIndex Methods ifoldMap ∷ Monoid m ⇒ (() → a → m) → Maybe a → m ifoldMap' ∷ Monoid m ⇒ (() → a → m) → Maybe a → m ifoldr ∷ (() → a → b → b) → b → Maybe a → b ifoldl ∷ (() → b → a → b) → b → Maybe a → b ifoldr' ∷ (() → a → b → b) → b → Maybe a → b ifoldl' ∷ (() → b → a → b) → b → Maybe a → b
FunctorWithIndex () Maybe
Instance details Defined in WithIndex Methods imap ∷ (() → a → b) → Maybe a → Maybe b
TraversableWithIndex () Maybe
Instance details Defined in WithIndex Methods itraverse ∷ Applicative f ⇒ (() → a → f b) → Maybe a → f (Maybe b)
MonadBaseControl Maybe Maybe
Instance details Defined in Control.Monad.Trans.Control Associated Types type StM Maybe a Methods liftBaseWith ∷ (RunInBase Maybe Maybe → Maybe a) → Maybe a restoreM ∷ StM Maybe a → Maybe a
MonadError () Maybe	Since: mtl-2.2.2
Instance details Defined in Control.Monad.Error.Class Methods throwError ∷ () → Maybe a Source # catchError ∷ Maybe a → (() → Maybe a) → Maybe a Source #
(Typeable DefaultUni a, Lift DefaultUni a) ⇒ Lift DefaultUni (Maybe a) Source #
Instance details Defined in PlutusTx.Lift.Instances Methods lift ∷ Maybe a → RTCompile DefaultUni fun (Term TyName Name DefaultUni fun ()) Source #
PrettyBy config a ⇒ DefaultPrettyBy config (Maybe a)
Instance details Defined in Text.PrettyBy.Internal Methods defaultPrettyBy ∷ config → Maybe a → Doc ann Source # defaultPrettyListBy ∷ config → [Maybe a] → Doc ann Source #
PrettyDefaultBy config (Maybe a) ⇒ PrettyBy config (Maybe a)	By default a `[Maybe a]` is converted to `[a]` first and only then pretty-printed. `>>>` `braces $ prettyBy () (Just True)`{True} `>>>` `braces $ prettyBy () (Nothing :: Maybe Bool)`{} `>>>` `prettyBy () [Just False, Nothing, Just True]`[False, True] `>>>` `prettyBy () [Nothing, Just 'a', Just 'b', Nothing, Just 'c']`abc
Instance details Defined in Text.PrettyBy.Internal Methods prettyBy ∷ config → Maybe a → Doc ann Source # prettyListBy ∷ config → [Maybe a] → Doc ann Source #
Lift a ⇒ Lift (Maybe a ∷ Type)
Instance details Defined in Language.Haskell.TH.Syntax Methods lift ∷ Quote m ⇒ Maybe a → m Exp Source # liftTyped ∷ ∀ (m ∷ Type → Type). Quote m ⇒ Maybe a → Code m (Maybe a) Source #
FromJSON a ⇒ FromJSON (Maybe a)
Instance details Defined in Data.Aeson.Types.FromJSON Methods parseJSON ∷ Value → Parser (Maybe a) parseJSONList ∷ Value → Parser [Maybe a] omittedField ∷ Maybe (Maybe a)
ToJSON (CekMachineCostsBase Maybe)
Instance details Defined in UntypedPlutusCore.Evaluation.Machine.Cek.CekMachineCosts Methods toJSON ∷ CekMachineCostsBase Maybe → Value toEncoding ∷ CekMachineCostsBase Maybe → Encoding toJSONList ∷ [CekMachineCostsBase Maybe] → Value toEncodingList ∷ [CekMachineCostsBase Maybe] → Encoding omitField ∷ CekMachineCostsBase Maybe → Bool
ToJSON a ⇒ ToJSON (Maybe a)
Instance details Defined in Data.Aeson.Types.ToJSON Methods toJSON ∷ Maybe a → Value toEncoding ∷ Maybe a → Encoding toJSONList ∷ [Maybe a] → Value toEncodingList ∷ [Maybe a] → Encoding omitField ∷ Maybe a → Bool
Graph g ⇒ Graph (Maybe g)
Instance details Defined in Algebra.Graph.Class Associated Types type Vertex (Maybe g) Source # Methods empty ∷ Maybe g Source # vertex ∷ Vertex (Maybe g) → Maybe g Source # overlay ∷ Maybe g → Maybe g → Maybe g Source # connect ∷ Maybe g → Maybe g → Maybe g Source #
Preorder g ⇒ Preorder (Maybe g)
Instance details Defined in Algebra.Graph.Class
Reflexive g ⇒ Reflexive (Maybe g)
Instance details Defined in Algebra.Graph.Class
Transitive g ⇒ Transitive (Maybe g)
Instance details Defined in Algebra.Graph.Class
Undirected g ⇒ Undirected (Maybe g)
Instance details Defined in Algebra.Graph.Class
Data a ⇒ Data (Maybe a)	Since: base-4.0.0.0
Instance details Defined in Data.Data Methods gfoldl ∷ (∀ d b. Data d ⇒ c (d → b) → d → c b) → (∀ g. g → c g) → Maybe a → c (Maybe a) Source # gunfold ∷ (∀ b r. Data b ⇒ c (b → r) → c r) → (∀ r. r → c r) → Constr → c (Maybe a) Source # toConstr ∷ Maybe a → Constr Source # dataTypeOf ∷ Maybe a → DataType Source # dataCast1 ∷ Typeable t ⇒ (∀ d. Data d ⇒ c (t d)) → Maybe (c (Maybe a)) Source # dataCast2 ∷ Typeable t ⇒ (∀ d e. (Data d, Data e) ⇒ c (t d e)) → Maybe (c (Maybe a)) Source # gmapT ∷ (∀ b. Data b ⇒ b → b) → Maybe a → Maybe a Source # gmapQl ∷ (r → r' → r) → r → (∀ d. Data d ⇒ d → r') → Maybe a → r Source # gmapQr ∷ ∀ r r'. (r' → r → r) → r → (∀ d. Data d ⇒ d → r') → Maybe a → r Source # gmapQ ∷ (∀ d. Data d ⇒ d → u) → Maybe a → [u] Source # gmapQi ∷ Int → (∀ d. Data d ⇒ d → u) → Maybe a → u Source # gmapM ∷ Monad m ⇒ (∀ d. Data d ⇒ d → m d) → Maybe a → m (Maybe a) Source # gmapMp ∷ MonadPlus m ⇒ (∀ d. Data d ⇒ d → m d) → Maybe a → m (Maybe a) Source # gmapMo ∷ MonadPlus m ⇒ (∀ d. Data d ⇒ d → m d) → Maybe a → m (Maybe a) Source #
Semigroup a ⇒ Monoid (Maybe a)	Lift a semigroup into `Maybe` forming a `Monoid` according to http://en.wikipedia.org/wiki/Monoid: "Any semigroup `S` may be turned into a monoid simply by adjoining an element `e` not in `S` and defining `ee = e` and `es = s = se` for all `s ∈ S`." Since 4.11.0: constraint on inner `a` value generalised from `Monoid` to `Semigroup`. Since: base-2.1*
Instance details Defined in GHC.Base Methods mempty ∷ Maybe a Source # mappend ∷ Maybe a → Maybe a → Maybe a Source # mconcat ∷ [Maybe a] → Maybe a Source #
Semigroup a ⇒ Semigroup (Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) ∷ Maybe a → Maybe a → Maybe a Source # sconcat ∷ NonEmpty (Maybe a) → Maybe a Source # stimes ∷ Integral b ⇒ b → Maybe a → Maybe a Source #
Generic (Maybe a)
Instance details Defined in GHC.Generics Associated Types type Rep (Maybe a) ∷ Type → Type Source # Methods from ∷ Maybe a → Rep (Maybe a) x Source # to ∷ Rep (Maybe a) x → Maybe a Source #
SingKind a ⇒ SingKind (Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type DemoteRep (Maybe a) Methods fromSing ∷ ∀ (a0 ∷ Maybe a). Sing a0 → DemoteRep (Maybe a)
Read a ⇒ Read (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec ∷ Int → ReadS (Maybe a) Source # readList ∷ ReadS [Maybe a] Source # readPrec ∷ ReadPrec (Maybe a) Source # readListPrec ∷ ReadPrec [Maybe a] Source #
Show a ⇒ Show (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec ∷ Int → Maybe a → ShowS Source # show ∷ Maybe a → String Source # showList ∷ [Maybe a] → ShowS Source #
Default (Maybe a)
Instance details Defined in Data.Default.Internal Methods def ∷ Maybe a #
NFData a ⇒ NFData (Maybe a)
Instance details Defined in Control.DeepSeq Methods rnf ∷ Maybe a → () Source #
Buildable a ⇒ Buildable (Maybe a)
Instance details Defined in Formatting.Buildable Methods build ∷ Maybe a → Builder Source #
Eq a ⇒ Eq (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods (==) ∷ Maybe a → Maybe a → Bool Source # (/=) ∷ Maybe a → Maybe a → Bool Source #
Ord a ⇒ Ord (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods compare ∷ Maybe a → Maybe a → Ordering Source # (<) ∷ Maybe a → Maybe a → Bool Source # (<=) ∷ Maybe a → Maybe a → Bool Source # (>) ∷ Maybe a → Maybe a → Bool Source # (>=) ∷ Maybe a → Maybe a → Bool Source # max ∷ Maybe a → Maybe a → Maybe a Source # min ∷ Maybe a → Maybe a → Maybe a Source #
Hashable a ⇒ Hashable (Maybe a)
Instance details Defined in Data.Hashable.Class Methods hashWithSalt ∷ Int → Maybe a → Int Source # hash ∷ Maybe a → Int Source #
At (Maybe a)
Instance details Defined in Control.Lens.At Methods at ∷ Index (Maybe a) → Lens' (Maybe a) (Maybe (IxValue (Maybe a)))
Ixed (Maybe a)
Instance details Defined in Control.Lens.At Methods ix ∷ Index (Maybe a) → Traversal' (Maybe a) (IxValue (Maybe a))
AsEmpty (Maybe a)
Instance details Defined in Control.Lens.Empty Methods _Empty ∷ Prism' (Maybe a) ()
MonoFoldable (Maybe a)
Instance details Defined in Data.MonoTraversable Methods ofoldMap ∷ Monoid m ⇒ (Element (Maybe a) → m) → Maybe a → m Source # ofoldr ∷ (Element (Maybe a) → b → b) → b → Maybe a → b Source # ofoldl' ∷ (a0 → Element (Maybe a) → a0) → a0 → Maybe a → a0 Source # otoList ∷ Maybe a → [Element (Maybe a)] Source # oall ∷ (Element (Maybe a) → Bool) → Maybe a → Bool Source # oany ∷ (Element (Maybe a) → Bool) → Maybe a → Bool Source # onull ∷ Maybe a → Bool Source # olength ∷ Maybe a → Int Source # olength64 ∷ Maybe a → Int64 Source # ocompareLength ∷ Integral i ⇒ Maybe a → i → Ordering Source # otraverse_ ∷ Applicative f ⇒ (Element (Maybe a) → f b) → Maybe a → f () Source # ofor_ ∷ Applicative f ⇒ Maybe a → (Element (Maybe a) → f b) → f () Source # omapM_ ∷ Applicative m ⇒ (Element (Maybe a) → m ()) → Maybe a → m () Source # oforM_ ∷ Applicative m ⇒ Maybe a → (Element (Maybe a) → m ()) → m () Source # ofoldlM ∷ Monad m ⇒ (a0 → Element (Maybe a) → m a0) → a0 → Maybe a → m a0 Source # ofoldMap1Ex ∷ Semigroup m ⇒ (Element (Maybe a) → m) → Maybe a → m Source # ofoldr1Ex ∷ (Element (Maybe a) → Element (Maybe a) → Element (Maybe a)) → Maybe a → Element (Maybe a) Source # ofoldl1Ex' ∷ (Element (Maybe a) → Element (Maybe a) → Element (Maybe a)) → Maybe a → Element (Maybe a) Source # headEx ∷ Maybe a → Element (Maybe a) Source # lastEx ∷ Maybe a → Element (Maybe a) Source # unsafeHead ∷ Maybe a → Element (Maybe a) Source # unsafeLast ∷ Maybe a → Element (Maybe a) Source # maximumByEx ∷ (Element (Maybe a) → Element (Maybe a) → Ordering) → Maybe a → Element (Maybe a) Source # minimumByEx ∷ (Element (Maybe a) → Element (Maybe a) → Ordering) → Maybe a → Element (Maybe a) Source # oelem ∷ Element (Maybe a) → Maybe a → Bool Source # onotElem ∷ Element (Maybe a) → Maybe a → Bool Source #
MonoFunctor (Maybe a)
Instance details Defined in Data.MonoTraversable Methods omap ∷ (Element (Maybe a) → Element (Maybe a)) → Maybe a → Maybe a Source #
MonoPointed (Maybe a)
Instance details Defined in Data.MonoTraversable Methods opoint ∷ Element (Maybe a) → Maybe a Source #
MonoTraversable (Maybe a)
Instance details Defined in Data.MonoTraversable Methods otraverse ∷ Applicative f ⇒ (Element (Maybe a) → f (Element (Maybe a))) → Maybe a → f (Maybe a) Source # omapM ∷ Applicative m ⇒ (Element (Maybe a) → m (Element (Maybe a))) → Maybe a → m (Maybe a) Source #
HasBlueprintDefinition a ⇒ HasBlueprintDefinition (Maybe a) Source #
Instance details Defined in PlutusTx.Blueprint.Definition.Unroll Associated Types type Unroll (Maybe a) ∷ [Type] Source # Methods definitionId ∷ DefinitionId Source #
Eq a ⇒ Eq (Maybe a) Source #
Instance details Defined in PlutusTx.Eq Methods (==) ∷ Maybe a → Maybe a → Bool Source #
FromData a ⇒ FromData (Maybe a) Source #
Instance details Defined in PlutusTx.IsData.Instances Methods fromBuiltinData ∷ BuiltinData → Maybe (Maybe a) Source #
ToData a ⇒ ToData (Maybe a) Source #
Instance details Defined in PlutusTx.IsData.Instances Methods toBuiltinData ∷ Maybe a → BuiltinData Source #
UnsafeFromData a ⇒ UnsafeFromData (Maybe a) Source #
Instance details Defined in PlutusTx.IsData.Instances Methods unsafeFromBuiltinData ∷ BuiltinData → Maybe a Source #
Semigroup a ⇒ Monoid (Maybe a) Source #
Instance details Defined in PlutusTx.Monoid Methods mempty ∷ Maybe a Source #
Ord a ⇒ Ord (Maybe a) Source #
Instance details Defined in PlutusTx.Ord Methods compare ∷ Maybe a → Maybe a → Ordering Source # (<) ∷ Maybe a → Maybe a → Bool Source # (<=) ∷ Maybe a → Maybe a → Bool Source # (>) ∷ Maybe a → Maybe a → Bool Source # (>=) ∷ Maybe a → Maybe a → Bool Source # max ∷ Maybe a → Maybe a → Maybe a Source # min ∷ Maybe a → Maybe a → Maybe a Source #
Semigroup a ⇒ Semigroup (Maybe a) Source #
Instance details Defined in PlutusTx.Semigroup Methods (<>) ∷ Maybe a → Maybe a → Maybe a Source #
Show a ⇒ Show (Maybe a) Source #
Instance details Defined in PlutusTx.Show Methods showsPrec ∷ Integer → Maybe a → ShowS Source # show ∷ Maybe a → BuiltinString Source #
Pretty a ⇒ Pretty (Maybe a)	Ignore `Nothing`s, print `Just` contents. `>>>` `pretty (Just True)`True `>>>` `braces (pretty (Nothing :: Maybe Bool))`{} `>>>` `pretty [Just 1, Nothing, Just 3, Nothing]`[1, 3]
Instance details Defined in Prettyprinter.Internal Methods pretty ∷ Maybe a → Doc ann Source # prettyList ∷ [Maybe a] → Doc ann Source #
(Finite a, Uniform a) ⇒ Uniform (Maybe a)
Instance details Defined in System.Random.Internal Methods uniformM ∷ StatefulGen g m ⇒ g → m (Maybe a) Source #
Corecursive (Maybe a)
Instance details Defined in Data.Functor.Foldable Methods embed ∷ Base (Maybe a) (Maybe a) → Maybe a Source # ana ∷ (a0 → Base (Maybe a) a0) → a0 → Maybe a Source # apo ∷ (a0 → Base (Maybe a) (Either (Maybe a) a0)) → a0 → Maybe a Source # postpro ∷ Recursive (Maybe a) ⇒ (∀ b. Base (Maybe a) b → Base (Maybe a) b) → (a0 → Base (Maybe a) a0) → a0 → Maybe a Source # gpostpro ∷ (Recursive (Maybe a), Monad m) ⇒ (∀ b. m (Base (Maybe a) b) → Base (Maybe a) (m b)) → (∀ c. Base (Maybe a) c → Base (Maybe a) c) → (a0 → Base (Maybe a) (m a0)) → a0 → Maybe a Source #
Recursive (Maybe a)
Instance details Defined in Data.Functor.Foldable Methods project ∷ Maybe a → Base (Maybe a) (Maybe a) Source # cata ∷ (Base (Maybe a) a0 → a0) → Maybe a → a0 Source # para ∷ (Base (Maybe a) (Maybe a, a0) → a0) → Maybe a → a0 Source # gpara ∷ (Corecursive (Maybe a), Comonad w) ⇒ (∀ b. Base (Maybe a) (w b) → w (Base (Maybe a) b)) → (Base (Maybe a) (EnvT (Maybe a) w a0) → a0) → Maybe a → a0 Source # prepro ∷ Corecursive (Maybe a) ⇒ (∀ b. Base (Maybe a) b → Base (Maybe a) b) → (Base (Maybe a) a0 → a0) → Maybe a → a0 Source # gprepro ∷ (Corecursive (Maybe a), Comonad w) ⇒ (∀ b. Base (Maybe a) (w b) → w (Base (Maybe a) b)) → (∀ c. Base (Maybe a) c → Base (Maybe a) c) → (Base (Maybe a) (w a0) → a0) → Maybe a → a0 Source #
Serialise a ⇒ Serialise (Maybe a)	Since: serialise-0.2.0.0
Instance details Defined in Codec.Serialise.Class Methods encode ∷ Maybe a → Encoding Source # decode ∷ Decoder s (Maybe a) Source # encodeList ∷ [Maybe a] → Encoding Source # decodeList ∷ Decoder s [Maybe a] Source #
Pretty a ⇒ Pretty (Maybe a)
Instance details Defined in Text.PrettyPrint.Annotated.WL Methods pretty ∷ Maybe a → Doc b prettyList ∷ [Maybe a] → Doc b
(HasBlueprintDefinition a, HasSchemaDefinition a referencedTypes) ⇒ HasBlueprintSchema (Maybe a) referencedTypes Source #
Instance details Defined in PlutusTx.IsData.Instances Methods schema ∷ Schema referencedTypes Source #
SingI ('Nothing ∷ Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods sing ∷ Sing 'Nothing
Each (Maybe a) (Maybe b) a b
Instance details Defined in Control.Lens.Each Methods each ∷ Traversal (Maybe a) (Maybe b) a b
Each (Maybe a) (Maybe b) a b
Instance details Defined in Lens.Micro.Internal Methods each ∷ Traversal (Maybe a) (Maybe b) a b Source #
SingI a2 ⇒ SingI ('Just a2 ∷ Maybe a1)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods sing ∷ Sing ('Just a2)
Typeable DefaultUni Maybe Source #
Instance details Defined in PlutusTx.Lift.Instances Methods typeRep ∷ Proxy Maybe → RTCompile DefaultUni fun (Type TyName DefaultUni ()) Source #
type Failure Maybe
Instance details Defined in Basement.Monad type Failure Maybe = ()
type Rep1 Maybe	Since: base-4.6.0.0
Instance details Defined in GHC.Generics type Rep1 Maybe = D1 ('MetaData "Maybe" "GHC.Maybe" "base" 'False) (C1 ('MetaCons "Nothing" 'PrefixI 'False) (U1 ∷ Type → Type) :+: C1 ('MetaCons "Just" 'PrefixI 'False) (S1 ('MetaSel ('Nothing ∷ Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))
type StM Maybe a
Instance details Defined in Control.Monad.Trans.Control type StM Maybe a = a
type Vertex (Maybe g)
Instance details Defined in Algebra.Graph.Class type Vertex (Maybe g) = Vertex g
type DemoteRep (Maybe a)
Instance details Defined in GHC.Generics type DemoteRep (Maybe a) = Maybe (DemoteRep a)
type Rep (Maybe a)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics type Rep (Maybe a) = D1 ('MetaData "Maybe" "GHC.Maybe" "base" 'False) (C1 ('MetaCons "Nothing" 'PrefixI 'False) (U1 ∷ Type → Type) :+: C1 ('MetaCons "Just" 'PrefixI 'False) (S1 ('MetaSel ('Nothing ∷ Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
data Sing (b ∷ Maybe a)
Instance details Defined in GHC.Generics data Sing (b ∷ Maybe a) where SNothing ∷ ∀ {a}. Sing ('Nothing ∷ Maybe a) SJust ∷ ∀ {a} (a1 ∷ a). Sing a1 → Sing ('Just a1)
type Index (Maybe a)
Instance details Defined in Control.Lens.At type Index (Maybe a) = ()
type IxValue (Maybe a)
Instance details Defined in Control.Lens.At type IxValue (Maybe a) = a
type Element (Maybe a)
Instance details Defined in Data.MonoTraversable type Element (Maybe a) = a
type Unroll (Maybe a) Source #
Instance details Defined in PlutusTx.Blueprint.Definition.Unroll type Unroll (Maybe a) = Insert (Maybe a) (Unrolled a)
type Base (Maybe a)	Example boring stub for non-recursive data types
Instance details Defined in Data.Functor.Foldable type Base (Maybe a) = Const (Maybe a) ∷ Type → Type

isJust ∷ Maybe a → Bool Source #

Check if a Maybe a is Just a

>>> isJust Nothing
False
>>> isJust (Just "plutus")
True

isNothing ∷ Maybe a → Bool Source #

Check if a Maybe a is Nothing

>>> isNothing Nothing
True
>>> isNothing (Just "plutus")
False

maybe ∷ b → (a → b) → Maybe a → b Source #

Plutus Tx version of maybe.

>>> maybe "platypus" (\s -> s) (Just "plutus")
"plutus"
>>> maybe "platypus" (\s -> s) Nothing
"platypus"

fromMaybe ∷ a → Maybe a → a Source #

Plutus Tx version of fromMaybe

mapMaybe ∷ (a → Maybe b) → [a] → [b] Source #

Plutus Tx version of mapMaybe.

>>> mapMaybe (\i -> if i == 2 then Just '2' else Nothing) [1, 2, 3, 4]
"2"