Data.Mergeful.Item

A way to synchronise an item with safe merge conflicts.

The item is "zero or one" value. One could say that Item a = Maybe a but there are so such types here. This methaphor just serves as explanation

The setup is as follows:

• A central server is set up to synchronise with
• Each client synchronises with the central server, but never with eachother

A client should operate as follows:

The clients starts with an initialClientItem.

• The client produces a ItemSyncRequest with makeItemSyncRequest.
• The client sends that request to the central server and gets a ItemSyncResponse.
• The client then updates its local store with mergeItemSyncResponseRaw or mergeItemSyncResponseIgnoreProblems.

The central server should operate as follows:

The server starts with an initialServerItem.

• The server accepts a ItemSyncRequest.
• The server performs operations according to the functionality of processServerItemSync.
• The server respons with a ItemSyncResponse.

WARNING: This whole approach can break down if a server resets its server times or if a client syncs with two different servers using the same server times.

Documentation

initialClientItem :: ClientItem a

A client item to start with.

It contains no value.

initialItemSyncRequest :: ItemSyncRequest a

An intial ItemSyncRequest to start with.

It just asks the server to send over whatever it knows.

makeItemSyncRequest :: ClientItem a -> ItemSyncRequest a

Produce an ItemSyncRequest from a ClientItem.

Send this to the server for synchronisation.

mergeItemSyncResponseFromServer :: ClientItem a -> ItemSyncResponse a -> ClientItem a

mergeItemSyncResponseFromClient :: ClientItem a -> ItemSyncResponse a -> ClientItem a

mergeItemSyncResponseUsingCRDT :: (a -> a -> a) -> ClientItem a -> ItemSyncResponse a -> ClientItem a

mergeItemSyncResponseUsingStrategy :: ItemMergeStrategy a -> ClientItem a -> ItemSyncResponse a -> ClientItem a

mergeFromServer :: ClientItem a -> ItemMergeResult a -> ClientItem a

Resolve an ItemMergeResult by taking whatever the server gave the client.

Pro: Clients will converge on the same value.

Con: Conflicting updates will be lost.

mergeFromServerStrategy :: ItemMergeStrategy a

A merge strategy that takes whatever the server gave the client.

Pro: Clients will converge on the same value.

Con: Conflicting updates will be lost.

mergeFromClient :: ClientItem a -> ItemMergeResult a -> ClientItem a

Resolve an ItemMergeResult by keeping whatever the client had.

Pro: does not lose data

Con: Clients will diverge when a conflict occurs

mergeFromClientStrategy :: ItemMergeStrategy a

A merge strategy that keeps whatever the client had.

Pro: does not lose data

Con: Clients will diverge when a conflict occurs

mergeUsingCRDT :: (a -> a -> a) -> ClientItem a -> ItemMergeResult a -> ClientItem a

mergeUsingCRDTStrategy :: (a -> a -> a) -> ItemMergeStrategy a

A merge strategy that uses a CRDT merging function to merge items.

In case of other-than-change conflicts, this will be the same as the mergeFromServerStrategy strategy. If this is not what you want, create your own ItemMergeStrategy manually.

data ItemMergeStrategy a

A strategy to merge conflicts for item synchronisation

Constructors

ItemMergeStrategy

Fields

• itemMergeStrategyMergeChangeConflict :: !(a -> a -> ChangeConflictResolution a)

  How to merge modification conflicts

  The first argument is the client item and the second argument is the server item.

• itemMergeStrategyMergeClientDeletedConflict :: !(a -> ClientDeletedConflictResolution)

  How to merge conflicts where the client deleted an item that the server modified

• itemMergeStrategyMergeServerDeletedConflict :: !(a -> ServerDeletedConflictResolution)

  How to merge conflicts where the server deleted an item that the client modified

Instances

Generic (ItemMergeStrategy a)

Defined in Data.Mergeful.Item

Associated Types

type Rep (ItemMergeStrategy a) :: Type -> Type

Methods

from :: ItemMergeStrategy a -> Rep (ItemMergeStrategy a) x

to :: Rep (ItemMergeStrategy a) x -> ItemMergeStrategy a

type Rep (ItemMergeStrategy a)

Defined in Data.Mergeful.Item

type Rep (ItemMergeStrategy a) = D1 ('MetaData "ItemMergeStrategy" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) (C1 ('MetaCons "ItemMergeStrategy" 'PrefixI 'True) (S1 ('MetaSel ('Just "itemMergeStrategyMergeChangeConflict") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (a -> a -> ChangeConflictResolution a)) :*: (S1 ('MetaSel ('Just "itemMergeStrategyMergeClientDeletedConflict") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (a -> ClientDeletedConflictResolution)) :*: S1 ('MetaSel ('Just "itemMergeStrategyMergeServerDeletedConflict") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (a -> ServerDeletedConflictResolution)))))

data ChangeConflictResolution a

Constructors

KeepLocal

TakeRemote

Merged a

Instances

Eq a => Eq (ChangeConflictResolution a)

Defined in Data.Mergeful.Item

Methods

(==) :: ChangeConflictResolution a -> ChangeConflictResolution a -> Bool

(/=) :: ChangeConflictResolution a -> ChangeConflictResolution a -> Bool

Show a => Show (ChangeConflictResolution a)

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ChangeConflictResolution a -> ShowS

show :: ChangeConflictResolution a -> String

showList :: [ChangeConflictResolution a] -> ShowS

Generic (ChangeConflictResolution a)

Defined in Data.Mergeful.Item

Associated Types

type Rep (ChangeConflictResolution a) :: Type -> Type

Methods

from :: ChangeConflictResolution a -> Rep (ChangeConflictResolution a) x

to :: Rep (ChangeConflictResolution a) x -> ChangeConflictResolution a

type Rep (ChangeConflictResolution a)

Defined in Data.Mergeful.Item

type Rep (ChangeConflictResolution a) = D1 ('MetaData "ChangeConflictResolution" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) (C1 ('MetaCons "KeepLocal" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "TakeRemote" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Merged" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a))))

data ClientDeletedConflictResolution

Constructors

TakeRemoteChange

StayDeleted

Instances

Eq ClientDeletedConflictResolution

Defined in Data.Mergeful.Item

Methods

(==) :: ClientDeletedConflictResolution -> ClientDeletedConflictResolution -> Bool

(/=) :: ClientDeletedConflictResolution -> ClientDeletedConflictResolution -> Bool

Show ClientDeletedConflictResolution

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ClientDeletedConflictResolution -> ShowS

show :: ClientDeletedConflictResolution -> String

showList :: [ClientDeletedConflictResolution] -> ShowS

Generic ClientDeletedConflictResolution

Defined in Data.Mergeful.Item

Associated Types

type Rep ClientDeletedConflictResolution :: Type -> Type

Methods

from :: ClientDeletedConflictResolution -> Rep ClientDeletedConflictResolution x

to :: Rep ClientDeletedConflictResolution x -> ClientDeletedConflictResolution

type Rep ClientDeletedConflictResolution

Defined in Data.Mergeful.Item

type Rep ClientDeletedConflictResolution = D1 ('MetaData "ClientDeletedConflictResolution" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) (C1 ('MetaCons "TakeRemoteChange" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "StayDeleted" 'PrefixI 'False) (U1 :: Type -> Type))

data ServerDeletedConflictResolution

Constructors

KeepLocalChange

Delete

Instances

Eq ServerDeletedConflictResolution

Defined in Data.Mergeful.Item

Methods

(==) :: ServerDeletedConflictResolution -> ServerDeletedConflictResolution -> Bool

(/=) :: ServerDeletedConflictResolution -> ServerDeletedConflictResolution -> Bool

Show ServerDeletedConflictResolution

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ServerDeletedConflictResolution -> ShowS

show :: ServerDeletedConflictResolution -> String

showList :: [ServerDeletedConflictResolution] -> ShowS

Generic ServerDeletedConflictResolution

Defined in Data.Mergeful.Item

Associated Types

type Rep ServerDeletedConflictResolution :: Type -> Type

Methods

from :: ServerDeletedConflictResolution -> Rep ServerDeletedConflictResolution x

to :: Rep ServerDeletedConflictResolution x -> ServerDeletedConflictResolution

type Rep ServerDeletedConflictResolution

Defined in Data.Mergeful.Item

type Rep ServerDeletedConflictResolution = D1 ('MetaData "ServerDeletedConflictResolution" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) (C1 ('MetaCons "KeepLocalChange" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Delete" 'PrefixI 'False) (U1 :: Type -> Type))

mergeUsingStrategy :: ItemMergeStrategy a -> ClientItem a -> ItemMergeResult a -> ClientItem a

Resolve an ItemMergeResult using a given merge strategy.

This function ignores MergeMismatch and will just return the original ClientItem in that case.

In order for clients to converge on the same item correctly, this function must be:

• Associative
• Idempotent
• The same on all clients

mergeItemSyncResponseRaw :: ClientItem a -> ItemSyncResponse a -> ItemMergeResult a

Merge an ItemSyncResponse into the current ClientItem.

This function will not make any decisions about what to do with conflicts or mismatches between the request and the response. It only produces a ItemMergeResult so you can decide what to do with it.

data ItemMergeResult a

Constructors

MergeSuccess !(ClientItem a)

The merger went succesfully, no conflicts or desyncs

MergeConflict !a !(Timed a)

The item at the server side | There was a merge conflict. The client had deleted the item while the server had modified it.

MergeConflictClientDeleted !(Timed a)

The item at the server side | There was a merge conflict. The server had deleted the item while the client had modified it.

MergeConflictServerDeleted !a

The item at the client side | The server responded with a response that did not make sense given the client's request.

MergeMismatch

Instances

Eq a => Eq (ItemMergeResult a)

Defined in Data.Mergeful.Item

Methods

(==) :: ItemMergeResult a -> ItemMergeResult a -> Bool

(/=) :: ItemMergeResult a -> ItemMergeResult a -> Bool

Show a => Show (ItemMergeResult a)

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ItemMergeResult a -> ShowS

show :: ItemMergeResult a -> String

showList :: [ItemMergeResult a] -> ShowS

Generic (ItemMergeResult a)

Defined in Data.Mergeful.Item

Associated Types

type Rep (ItemMergeResult a) :: Type -> Type

Methods

from :: ItemMergeResult a -> Rep (ItemMergeResult a) x

to :: Rep (ItemMergeResult a) x -> ItemMergeResult a

NFData a => NFData (ItemMergeResult a)

Defined in Data.Mergeful.Item

Methods

rnf :: ItemMergeResult a -> ()

Validity a => Validity (ItemMergeResult a)

Defined in Data.Mergeful.Item

Methods

validate :: ItemMergeResult a -> Validation

type Rep (ItemMergeResult a)

Defined in Data.Mergeful.Item

type Rep (ItemMergeResult a) = D1 ('MetaData "ItemMergeResult" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) ((C1 ('MetaCons "MergeSuccess" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (ClientItem a))) :+: C1 ('MetaCons "MergeConflict" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a)))) :+: (C1 ('MetaCons "MergeConflictClientDeleted" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: (C1 ('MetaCons "MergeConflictServerDeleted" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a)) :+: C1 ('MetaCons "MergeMismatch" 'PrefixI 'False) (U1 :: Type -> Type))))

Server side

initialServerItem :: ServerItem a

A server item to start with.

It contains no value.

processServerItemSync :: ServerItem a -> ItemSyncRequest a -> (ItemSyncResponse a, ServerItem a)

Serve an ItemSyncRequest using the current ServerItem, producing an ItemSyncResponse and a new ServerItem.

Types, for reference

data ClientItem a

Constructors

ClientEmpty

There is no item on the client side

ClientAdded !a

There is is an item but the server is not aware of it yet.

ClientItemSynced !(Timed a)

There is is an item and it has been synced with the server.

ClientItemSyncedButChanged !(Timed a)

There is is an item and it has been synced with the server, but it has since been modified.

ClientDeleted !ServerTime

There was an item, and it has been deleted locally, but the server has not been made aware of this.

Instances

Eq a => Eq (ClientItem a)

Defined in Data.Mergeful.Item

Methods

(==) :: ClientItem a -> ClientItem a -> Bool

(/=) :: ClientItem a -> ClientItem a -> Bool

Show a => Show (ClientItem a)

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ClientItem a -> ShowS

show :: ClientItem a -> String

showList :: [ClientItem a] -> ShowS

Generic (ClientItem a)

Defined in Data.Mergeful.Item

Associated Types

type Rep (ClientItem a) :: Type -> Type

Methods

from :: ClientItem a -> Rep (ClientItem a) x

to :: Rep (ClientItem a) x -> ClientItem a

HasCodec a => ToJSON (ClientItem a)

Defined in Data.Mergeful.Item

Methods

toJSON :: ClientItem a -> Value

toEncoding :: ClientItem a -> Encoding

toJSONList :: [ClientItem a] -> Value

toEncodingList :: [ClientItem a] -> Encoding

HasCodec a => FromJSON (ClientItem a)

Defined in Data.Mergeful.Item

Methods

parseJSON :: Value -> Parser (ClientItem a)

parseJSONList :: Value -> Parser [ClientItem a]

HasCodec a => HasCodec (ClientItem a)

Defined in Data.Mergeful.Item

Methods

codec :: JSONCodec (ClientItem a)

listCodecForStringCompatibility :: JSONCodec [ClientItem a]

NFData a => NFData (ClientItem a)

Defined in Data.Mergeful.Item

Methods

rnf :: ClientItem a -> ()

Validity a => Validity (ClientItem a)

Defined in Data.Mergeful.Item

Methods

validate :: ClientItem a -> Validation

type Rep (ClientItem a)

Defined in Data.Mergeful.Item

type Rep (ClientItem a) = D1 ('MetaData "ClientItem" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) ((C1 ('MetaCons "ClientEmpty" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ClientAdded" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a))) :+: (C1 ('MetaCons "ClientItemSynced" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: (C1 ('MetaCons "ClientItemSyncedButChanged" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: C1 ('MetaCons "ClientDeleted" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 ServerTime)))))

data ItemSyncRequest a

Constructors

ItemSyncRequestPoll

There is no item locally

ItemSyncRequestNew !a

There is an item locally that has not been synced to the server yet.

ItemSyncRequestKnown !ServerTime

There is an item locally that was synced at the given ServerTime

ItemSyncRequestKnownButChanged !(Timed a)

There is an item locally that was synced at the given ServerTime but it has been changed since then.

ItemSyncRequestDeletedLocally !ServerTime

There was an item locally that has been deleted but the deletion wasn't synced to the server yet.

Instances

Eq a => Eq (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Methods

(==) :: ItemSyncRequest a -> ItemSyncRequest a -> Bool

(/=) :: ItemSyncRequest a -> ItemSyncRequest a -> Bool

Show a => Show (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ItemSyncRequest a -> ShowS

show :: ItemSyncRequest a -> String

showList :: [ItemSyncRequest a] -> ShowS

Generic (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Associated Types

type Rep (ItemSyncRequest a) :: Type -> Type

Methods

from :: ItemSyncRequest a -> Rep (ItemSyncRequest a) x

to :: Rep (ItemSyncRequest a) x -> ItemSyncRequest a

HasCodec a => ToJSON (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Methods

toJSON :: ItemSyncRequest a -> Value

toEncoding :: ItemSyncRequest a -> Encoding

toJSONList :: [ItemSyncRequest a] -> Value

toEncodingList :: [ItemSyncRequest a] -> Encoding

HasCodec a => FromJSON (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Methods

parseJSON :: Value -> Parser (ItemSyncRequest a)

parseJSONList :: Value -> Parser [ItemSyncRequest a]

HasCodec a => HasCodec (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Methods

codec :: JSONCodec (ItemSyncRequest a)

listCodecForStringCompatibility :: JSONCodec [ItemSyncRequest a]

NFData a => NFData (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Methods

rnf :: ItemSyncRequest a -> ()

Validity a => Validity (ItemSyncRequest a)

Defined in Data.Mergeful.Item

Methods

validate :: ItemSyncRequest a -> Validation

type Rep (ItemSyncRequest a)

Defined in Data.Mergeful.Item

type Rep (ItemSyncRequest a) = D1 ('MetaData "ItemSyncRequest" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) ((C1 ('MetaCons "ItemSyncRequestPoll" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ItemSyncRequestNew" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a))) :+: (C1 ('MetaCons "ItemSyncRequestKnown" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 ServerTime)) :+: (C1 ('MetaCons "ItemSyncRequestKnownButChanged" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: C1 ('MetaCons "ItemSyncRequestDeletedLocally" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 ServerTime)))))

data ItemSyncResponse a

Constructors

ItemSyncResponseInSyncEmpty

The client and server are fully in sync, and both empty

Nothing needs to be done at the client side.

ItemSyncResponseInSyncFull

The client and server are fully in sync.

Nothing needs to be done at the client side.

ItemSyncResponseClientAdded !ServerTime

The client added an item and server has succesfully been made aware of that.

The client needs to update its server time

ItemSyncResponseClientChanged !ServerTime

The client changed an item and server has succesfully been made aware of that.

The client needs to update its server time

ItemSyncResponseClientDeleted

The client deleted an item and server has succesfully been made aware of that.

The client can delete it from its deleted items

ItemSyncResponseServerAdded !(Timed a)

This item has been added on the server side

The client should add it too.

ItemSyncResponseServerChanged !(Timed a)

This item has been modified on the server side.

The client should modify it too.

ItemSyncResponseServerDeleted

The item was deleted on the server side

The client should delete it too.

ItemSyncResponseConflict !(Timed a)

The item at the server side | A conflict occurred.

The server has an item but the client does not. The server kept its part, the client can either take whatever the server gave them or deal with the conflict somehow, and then try to re-sync.

ItemSyncResponseConflictClientDeleted !(Timed a)

The item at the server side | A conflict occurred.

The client has a (modified) item but the server does not have any item. The server left its item deleted, the client can either delete its item too or deal with the conflict somehow, and then try to re-sync.

ItemSyncResponseConflictServerDeleted

Instances

Eq a => Eq (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Methods

(==) :: ItemSyncResponse a -> ItemSyncResponse a -> Bool

(/=) :: ItemSyncResponse a -> ItemSyncResponse a -> Bool

Show a => Show (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ItemSyncResponse a -> ShowS

show :: ItemSyncResponse a -> String

showList :: [ItemSyncResponse a] -> ShowS

Generic (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Associated Types

type Rep (ItemSyncResponse a) :: Type -> Type

Methods

from :: ItemSyncResponse a -> Rep (ItemSyncResponse a) x

to :: Rep (ItemSyncResponse a) x -> ItemSyncResponse a

HasCodec a => ToJSON (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Methods

toJSON :: ItemSyncResponse a -> Value

toEncoding :: ItemSyncResponse a -> Encoding

toJSONList :: [ItemSyncResponse a] -> Value

toEncodingList :: [ItemSyncResponse a] -> Encoding

HasCodec a => FromJSON (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Methods

parseJSON :: Value -> Parser (ItemSyncResponse a)

parseJSONList :: Value -> Parser [ItemSyncResponse a]

HasCodec a => HasCodec (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Methods

codec :: JSONCodec (ItemSyncResponse a)

listCodecForStringCompatibility :: JSONCodec [ItemSyncResponse a]

NFData a => NFData (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Methods

rnf :: ItemSyncResponse a -> ()

Validity a => Validity (ItemSyncResponse a)

Defined in Data.Mergeful.Item

Methods

validate :: ItemSyncResponse a -> Validation

type Rep (ItemSyncResponse a)

Defined in Data.Mergeful.Item

type Rep (ItemSyncResponse a) = D1 ('MetaData "ItemSyncResponse" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) (((C1 ('MetaCons "ItemSyncResponseInSyncEmpty" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ItemSyncResponseInSyncFull" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "ItemSyncResponseClientAdded" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 ServerTime)) :+: (C1 ('MetaCons "ItemSyncResponseClientChanged" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 ServerTime)) :+: C1 ('MetaCons "ItemSyncResponseClientDeleted" 'PrefixI 'False) (U1 :: Type -> Type)))) :+: ((C1 ('MetaCons "ItemSyncResponseServerAdded" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: (C1 ('MetaCons "ItemSyncResponseServerChanged" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: C1 ('MetaCons "ItemSyncResponseServerDeleted" 'PrefixI 'False) (U1 :: Type -> Type))) :+: (C1 ('MetaCons "ItemSyncResponseConflict" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: (C1 ('MetaCons "ItemSyncResponseConflictClientDeleted" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))) :+: C1 ('MetaCons "ItemSyncResponseConflictServerDeleted" 'PrefixI 'False) (U1 :: Type -> Type)))))

data ServerItem a

Constructors

ServerEmpty

There is no item on the server side

ServerFull !(Timed a)

There is an item on the server side, and it was last synced at the given ServerTime.

Instances

Eq a => Eq (ServerItem a)

Defined in Data.Mergeful.Item

Methods

(==) :: ServerItem a -> ServerItem a -> Bool

(/=) :: ServerItem a -> ServerItem a -> Bool

Show a => Show (ServerItem a)

Defined in Data.Mergeful.Item

Methods

showsPrec :: Int -> ServerItem a -> ShowS

show :: ServerItem a -> String

showList :: [ServerItem a] -> ShowS

Generic (ServerItem a)

Defined in Data.Mergeful.Item

Associated Types

type Rep (ServerItem a) :: Type -> Type

Methods

from :: ServerItem a -> Rep (ServerItem a) x

to :: Rep (ServerItem a) x -> ServerItem a

HasCodec a => ToJSON (ServerItem a)

Defined in Data.Mergeful.Item

Methods

toJSON :: ServerItem a -> Value

toEncoding :: ServerItem a -> Encoding

toJSONList :: [ServerItem a] -> Value

toEncodingList :: [ServerItem a] -> Encoding

HasCodec a => FromJSON (ServerItem a)

Defined in Data.Mergeful.Item

Methods

parseJSON :: Value -> Parser (ServerItem a)

parseJSONList :: Value -> Parser [ServerItem a]

HasCodec a => HasCodec (ServerItem a)

Defined in Data.Mergeful.Item

Methods

codec :: JSONCodec (ServerItem a)

listCodecForStringCompatibility :: JSONCodec [ServerItem a]

NFData a => NFData (ServerItem a)

Defined in Data.Mergeful.Item

Methods

rnf :: ServerItem a -> ()

Validity a => Validity (ServerItem a)

Defined in Data.Mergeful.Item

Methods

validate :: ServerItem a -> Validation

type Rep (ServerItem a)

Defined in Data.Mergeful.Item

type Rep (ServerItem a) = D1 ('MetaData "ServerItem" "Data.Mergeful.Item" "mergeful-0.3.0.0-IufP8wiUmUb8vtwEhWnzS0" 'False) (C1 ('MetaCons "ServerEmpty" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ServerFull" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (Timed a))))