SuperRecord.Variant.Tagged

Documentation

type TaggedVariant opts = Variant opts

Just a type alias vor Variant

toTaggedVariant :: forall opts lbl a pos. (KnownSymbol lbl, VariantMember (lbl := a) opts, KnownNat pos, VariantPos (lbl := a) opts ~ pos) => FldProxy lbl -> a -> TaggedVariant opts

Helper function to construct a tagged variant value given the tag and the value. Note that you can use OverloadedLabels for nicer syntax to construct the FldProxy.

toTaggedVariant #myTag "myValue"

fromTaggedVariant :: forall opts lbl a pos. (KnownSymbol lbl, VariantMember (lbl := a) opts, KnownNat pos, VariantPos (lbl := a) opts ~ pos) => FldProxy lbl -> TaggedVariant opts -> Maybe a

Convert a variant back to a common Haskell type. Returns nothing if the variant is not of the right tag and type.

taggedVariantCase :: forall lbl t ts r. FldProxy lbl -> (t -> r) -> VariantMatch r ts -> VariantMatch r ((lbl := t) ': ts)

Nicer syntax for VariantCase for tagged variants.

newtype JsonTaggedVariant opts

Newtype wrapper for TaggedVariant which provides a useful JSON encoding of tagged variants in the form {"tag": value}

Constructors

JsonTaggedVariant

Fields

• unJsonTaggedVariant :: TaggedVariant opts

Instances

(KnownSymbol lbl, ToJSON t, ToJSON (JsonTaggedVariant ts)) => ToJSON (JsonTaggedVariant ((:) * ((:=) lbl t) ts))

Methods

toJSON :: JsonTaggedVariant ((* ': (lbl := t)) ts) -> Value

toEncoding :: JsonTaggedVariant ((* ': (lbl := t)) ts) -> Encoding

toJSONList :: [JsonTaggedVariant ((* ': (lbl := t)) ts)] -> Value

toEncodingList :: [JsonTaggedVariant ((* ': (lbl := t)) ts)] -> Encoding

ToJSON (JsonTaggedVariant ([] *))

Methods

toJSON :: JsonTaggedVariant [*] -> Value

toEncoding :: JsonTaggedVariant [*] -> Encoding

toJSONList :: [JsonTaggedVariant [*]] -> Value

toEncodingList :: [JsonTaggedVariant [*]] -> Encoding

(FromJSON t, FromJSON (JsonTaggedVariant ts), KnownSymbol lbl) => FromJSON (JsonTaggedVariant ((:) * ((:=) lbl t) ts))

Methods

parseJSON :: Value -> Parser (JsonTaggedVariant ((* ': (lbl := t)) ts))

parseJSONList :: Value -> Parser [JsonTaggedVariant ((* ': (lbl := t)) ts)]

FromJSON (JsonTaggedVariant ([] *))

Methods

parseJSON :: Value -> Parser (JsonTaggedVariant [*])

parseJSONList :: Value -> Parser [JsonTaggedVariant [*]]