Safe Haskell	None
Language	Haskell2010

Rel8.Decoder

Synopsis

data Decoder a = Decoder {
- binary :: Value a
- text :: Parser a
}
type Parser a = ByteString -> Either String a
parseDecoder :: (a -> Either String b) -> Decoder a -> Decoder b

Documentation

data Decoder a Source #

Constructors

Decoder
Fields binary :: Value a How to deserialize from PostgreSQL's binary format. text :: Parser a How to deserialize from PostgreSQL's text format.

Instances

Instances details

Functor Decoder Source #
Instance details Defined in Rel8.Type.Decoder Methods fmap :: (a -> b) -> Decoder a -> Decoder b # (<$) :: a -> Decoder b -> Decoder a #

type Parser a = ByteString -> Either String a Source #

parseDecoder :: (a -> Either String b) -> Decoder a -> Decoder b Source #

Apply a parser to Decoder.

This can be used if the data stored in the database should only be subset of a given Decoder. The parser is applied when deserializing rows returned.