Database.DynamoDB.Types

Exceptions

data DynamoException

Exceptions thrown by some dynamodb-simple actions.

Constructors

DynamoException Text

Instances

Show DynamoException

Methods

showsPrec :: Int -> DynamoException -> ShowS

show :: DynamoException -> String

showList :: [DynamoException] -> ShowS

Exception DynamoException

Methods

toException :: DynamoException -> SomeException

fromException :: SomeException -> Maybe DynamoException

displayException :: DynamoException -> String

Marshalling

class DynamoEncodable a where

Typeclass showing that this datatype can be saved to DynamoDB.

Methods

dEncode :: a -> Maybe AttributeValue

Encode data. Return Nothing if attribute should be omitted.

dEncode :: (Show a, Read a) => a -> Maybe AttributeValue

Encode data. Return Nothing if attribute should be omitted.

dDecode :: Maybe AttributeValue -> Maybe a

Decode data. Return Nothing on parsing error, gets Nothing on input if the attribute was missing in the database.

dDecode :: (Show a, Read a) => Maybe AttributeValue -> Maybe a

Decode data. Return Nothing on parsing error, gets Nothing on input if the attribute was missing in the database.

dIsMissing :: a -> Bool

Aid for searching for empty list and hashmap; these can be represented both by empty list and by missing value, if this returns true, enhance search.

Instances

DynamoEncodable Bool

Methods

dEncode :: Bool -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Bool

dIsMissing :: Bool -> Bool

DynamoEncodable Double

Methods

dEncode :: Double -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Double

dIsMissing :: Double -> Bool

DynamoEncodable Int

Methods

dEncode :: Int -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Int

dIsMissing :: Int -> Bool

DynamoEncodable Integer

Methods

dEncode :: Integer -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Integer

dIsMissing :: Integer -> Bool

DynamoEncodable Word

Methods

dEncode :: Word -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Word

dIsMissing :: Word -> Bool

DynamoEncodable ByteString

Methods

dEncode :: ByteString -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe ByteString

dIsMissing :: ByteString -> Bool

DynamoEncodable Scientific

Methods

dEncode :: Scientific -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Scientific

dIsMissing :: Scientific -> Bool

DynamoEncodable Text

Methods

dEncode :: Text -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Text

dIsMissing :: Text -> Bool

DynamoEncodable Value

Partial encoding/decoding Aeson values. Empty strings get converted to NULL.

Methods

dEncode :: Value -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe Value

dIsMissing :: Value -> Bool

DynamoEncodable a => DynamoEncodable [a]

DynamoDB cannot represent empty items; [Maybe a] will lose Nothings.

Methods

dEncode :: [a] -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe [a]

dIsMissing :: [a] -> Bool

DynamoEncodable a => DynamoEncodable (Maybe a)

Maybe (Maybe a) will not work well; it will join the value in the database.

Methods

dEncode :: Maybe a -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe (Maybe a)

dIsMissing :: Maybe a -> Bool

(Ord a, DynamoScalar v a) => DynamoEncodable (Set a)

Methods

dEncode :: Set a -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe (Set a)

dIsMissing :: Set a -> Bool

(IsText t, DynamoEncodable a) => DynamoEncodable (HashMap t a)

Methods

dEncode :: HashMap t a -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe (HashMap t a)

dIsMissing :: HashMap t a -> Bool

DynamoEncodable a => DynamoEncodable (Tagged * v a)

Methods

dEncode :: Tagged * v a -> Maybe AttributeValue

dDecode :: Maybe AttributeValue -> Maybe (Tagged * v a)

dIsMissing :: Tagged * v a -> Bool

class (ScalarAuto v, DynamoEncodable a) => DynamoScalar v a | a -> v where

Typeclass signifying that this is a scalar attribute and can be used as a hash/sort key.

instance DynamoScalar Network.AWS.DynamoDB.Types.S T.Text where
   scalarEncode = ScS
   scalarDecode (ScS txt) = Just txt

Methods

scalarEncode :: a -> ScalarValue v

Scalars must have total encoding function

scalarEncode :: (Show a, Read a) => a -> ScalarValue S

Scalars must have total encoding function

scalarDecode :: ScalarValue v -> Maybe a

scalarDecode :: (Show a, Read a) => ScalarValue S -> Maybe a

Instances

DynamoScalar S Text

Methods

scalarEncode :: Text -> ScalarValue S

scalarDecode :: ScalarValue S -> Maybe Text

DynamoScalar N Double

Don't use Double as a part of primary key in a table. It is included here for convenience to be used as a range key in indexes.

Methods

scalarEncode :: Double -> ScalarValue N

scalarDecode :: ScalarValue N -> Maybe Double

DynamoScalar N Int

Methods

scalarEncode :: Int -> ScalarValue N

scalarDecode :: ScalarValue N -> Maybe Int

DynamoScalar N Integer

Methods

scalarEncode :: Integer -> ScalarValue N

scalarDecode :: ScalarValue N -> Maybe Integer

DynamoScalar N Word

Methods

scalarEncode :: Word -> ScalarValue N

scalarDecode :: ScalarValue N -> Maybe Word

DynamoScalar N Scientific

Double as a primary key isn't generally a good thing as equality on double is sometimes a little dodgy. Use scientific instead.

Methods

scalarEncode :: Scientific -> ScalarValue N

scalarDecode :: ScalarValue N -> Maybe Scientific

DynamoScalar B ByteString

Methods

scalarEncode :: ByteString -> ScalarValue B

scalarDecode :: ScalarValue B -> Maybe ByteString

DynamoScalar v a => DynamoScalar v (Tagged * x a)

Helper for tagged values

Methods

scalarEncode :: Tagged * x a -> ScalarValue v

scalarDecode :: ScalarValue v -> Maybe (Tagged * x a)

data ScalarValue v where

Datatype for encoding scalar values

Constructors

ScS :: !Text -> ScalarValue S

ScN :: !Scientific -> ScalarValue N

ScB :: !ByteString -> ScalarValue B

class (Eq a, Hashable a) => IsText a where

Class to limit certain operations to text-like only in queries. Members of this class can be keys to HashMap.

Minimal complete definition

toText, fromText

Methods

toText :: a -> Text

fromText :: Text -> a

Instances

IsText Text

Methods

toText :: Text -> Text

fromText :: Text -> Text

(Hashable (Tagged * t a), IsText a) => IsText (Tagged * t a)

Methods

toText :: Tagged * t a -> Text

fromText :: Text -> Tagged * t a

class IsNumber a

Class to limit +=. and -=. for updates.

Instances

IsNumber Double

IsNumber Int

IsNumber Integer

IsNumber a => IsNumber (Tagged * t a)

Query datatype

data RangeOper a where

Operation on range key for query.

Constructors

RangeEquals :: a -> RangeOper a

RangeLessThan :: a -> RangeOper a

RangeLessThanE :: a -> RangeOper a

RangeGreaterThan :: a -> RangeOper a

RangeGreaterThanE :: a -> RangeOper a

RangeBetween :: a -> a -> RangeOper a

RangeBeginsWith :: IsText a => a -> RangeOper a

Utility functions

dType :: forall a v. DynamoScalar v a => Proxy a -> ScalarAttributeType

dScalarEncode :: DynamoScalar v a => a -> AttributeValue