souffle-haskell-2.0.0: Souffle Datalog bindings for Haskell

Safe HaskellNone
LanguageHaskell2010

Language.Souffle.Class

Description

This module provides the top level API for Souffle related operations. It makes use of Haskell's powerful typesystem to make certain invalid states impossible to represent. It does this with a small type level DSL for describing properties of the Datalog program (see the Program and Fact typeclasses for more information).

The Souffle operations are exposed via 2 mtl-style interfaces (see MonadSouffle and MonadSouffleFileIO) that allows them to be integrated with existing monad transformer stacks.

This module also contains some helper type families for additional type safety and user-friendly error messages.

Synopsis

Documentation

class Program a where Source #

A typeclass for describing a datalog program.

Example usage (assuming the program was generated from path.dl and contains 2 facts: Edge and Reachable):

data Path = Path  -- Handle for the datalog program

instance Program Path where
  type ProgramFacts Path = '[Edge, Reachable]
  programName = const "path"

Associated Types

type ProgramFacts a :: [Type] Source #

A type level list of facts that belong to this program. This list is used to check that only known facts are added to a program.

Methods

programName :: a -> String Source #

Function for obtaining the name of a Datalog program. This has to be the same as the name of the .dl file (minus the extension).

class Marshal a => Fact a where Source #

A typeclass for data types representing a fact in datalog.

Example usage:

instance Fact Edge where
  type FactDirection Edge = 'Input
  factName = const "edge"

Associated Types

type FactDirection a :: Direction Source #

The direction or "mode" a fact can be used in. This is used to perform compile-time checks that a fact is only used in valid situations. For more information, see the Direction type.

Methods

factName :: Proxy a -> String Source #

Function for obtaining the name of a fact (has to be the same as described in the Datalog program).

It uses a Proxy to select the correct instance.

class Marshal a where Source #

A typeclass for providing a uniform API to marshal/unmarshal values between Haskell and Souffle datalog.

The marshalling is done via a stack-based approach, where elements are pushed/popped one by one. You need to make sure that the marshalling of values happens in the correct order or unexpected things might happen (including crashes). Pushing and popping of fields should happen in the same order (from left to right, as defined in Datalog).

Generic implementations for push and pop that perform the previously described behavior are available. This makes it possible to write very succinct code:

data Edge = Edge String String deriving Generic

instance Marshal Edge

Minimal complete definition

Nothing

Methods

push :: MonadPush m => a -> m () Source #

Marshals a value to the datalog side.

pop :: MonadPop m => m a Source #

Unmarshals a value from the datalog side.

push :: (Generic a, SimpleProduct a, GMarshal (Rep a), MonadPush m) => a -> m () Source #

Marshals a value to the datalog side.

pop :: (Generic a, SimpleProduct a, GMarshal (Rep a), MonadPop m) => m a Source #

Unmarshals a value from the datalog side.

Instances
Marshal Float Source # 
Instance details

Defined in Language.Souffle.Marshal

Methods

push :: MonadPush m => Float -> m () Source #

pop :: MonadPop m => m Float Source #

Marshal Int32 Source # 
Instance details

Defined in Language.Souffle.Marshal

Methods

push :: MonadPush m => Int32 -> m () Source #

pop :: MonadPop m => m Int32 Source #

Marshal Word32 Source # 
Instance details

Defined in Language.Souffle.Marshal

Methods

push :: MonadPush m => Word32 -> m () Source #

pop :: MonadPop m => m Word32 Source #

Marshal String Source # 
Instance details

Defined in Language.Souffle.Marshal

Methods

push :: MonadPush m => String -> m () Source #

pop :: MonadPop m => m String Source #

Marshal Text Source # 
Instance details

Defined in Language.Souffle.Marshal

Methods

push :: MonadPush m => Text -> m () Source #

pop :: MonadPop m => m Text Source #

Marshal Text Source # 
Instance details

Defined in Language.Souffle.Marshal

Methods

push :: MonadPush m => Text -> m () Source #

pop :: MonadPop m => m Text Source #

data Direction Source #

A datatype describing which operations a certain fact supports. The direction is from the datalog perspective, so that it aligns with ".decl" statements in Souffle.

Constructors

Input

Fact can only be stored in Datalog (using addFact/addFacts).

Output

Fact can only be read from Datalog (using getFacts/findFact).

InputOutput

Fact supports both reading from / writing to Datalog.

Internal

Supports neither reading from / writing to Datalog. This is used for facts that are only visible inside Datalog itself.

type family ContainsInputFact prog fact :: Constraint where ... Source #

A helper type family for checking if a specific Souffle Program contains a certain Fact. Additionally, it also checks if the fact is marked as either Input or InputOutput. This constraint will generate a user-friendly type error if these conditions are not met.

Equations

ContainsInputFact prog fact = (ContainsFact prog fact, IsInput fact (FactDirection fact)) 

type family ContainsOutputFact prog fact :: Constraint where ... Source #

A helper type family for checking if a specific Souffle Program contains a certain Fact. Additionally, it also checks if the fact is marked as either Output or InputOutput. This constraint will generate a user-friendly type error if these conditions are not met.

Equations

ContainsOutputFact prog fact = (ContainsFact prog fact, IsOutput fact (FactDirection fact)) 

type family ContainsFact prog fact :: Constraint where ... Source #

A helper type family for checking if a specific Souffle Program contains a certain Fact. This constraint will generate a user-friendly type error if this is not the case.

Equations

ContainsFact prog fact = CheckContains prog (ProgramFacts prog) fact 

class Monad m => MonadSouffle m where Source #

A mtl-style typeclass for Souffle-related actions.

Associated Types

type Handler m :: Type -> Type Source #

Represents a handle for interacting with a Souffle program.

The handle is used in all other functions of this typeclass to perform Souffle-related actions.

type CollectFacts m (c :: Type -> Type) :: Constraint Source #

Helper associated type constraint that allows collecting facts from Souffle in a list or vector. Only used internally.

Methods

run :: Handler m prog -> m () Source #

Runs the Souffle program.

setNumThreads :: Handler m prog -> Word64 -> m () Source #

Sets the number of CPU cores this Souffle program should use.

getNumThreads :: Handler m prog -> m Word64 Source #

Gets the number of CPU cores this Souffle program should use.

getFacts :: (Fact a, ContainsOutputFact prog a, CollectFacts m c) => Handler m prog -> m (c a) Source #

Returns all facts of a program. This function makes use of type inference to select the type of fact to return.

findFact :: (Fact a, ContainsOutputFact prog a, Eq a) => Handler m prog -> a -> m (Maybe a) Source #

Searches for a fact in a program. Returns Nothing if no matching fact was found; otherwise Just the fact.

Conceptually equivalent to List.find (== fact) <$> getFacts prog, but this operation can be implemented much faster.

addFact :: (Fact a, ContainsInputFact prog a) => Handler m prog -> a -> m () Source #

Adds a fact to the program.

addFacts :: (Foldable t, Fact a, ContainsInputFact prog a) => Handler m prog -> t a -> m () Source #

Adds multiple facts to the program. This function could be implemented in terms of addFact, but this is done as a minor optimization.

Instances
MonadSouffle SouffleM Source # 
Instance details

Defined in Language.Souffle.Interpreted

Associated Types

type Handler SouffleM :: Type -> Type Source #

type CollectFacts SouffleM c :: Constraint Source #

MonadSouffle SouffleM Source # 
Instance details

Defined in Language.Souffle.Compiled

Associated Types

type Handler SouffleM :: Type -> Type Source #

type CollectFacts SouffleM c :: Constraint Source #

MonadSouffle m => MonadSouffle (ExceptT e m) Source # 
Instance details

Defined in Language.Souffle.Class

Associated Types

type Handler (ExceptT e m) :: Type -> Type Source #

type CollectFacts (ExceptT e m) c :: Constraint Source #

Methods

run :: Handler (ExceptT e m) prog -> ExceptT e m () Source #

setNumThreads :: Handler (ExceptT e m) prog -> Word64 -> ExceptT e m () Source #

getNumThreads :: Handler (ExceptT e m) prog -> ExceptT e m Word64 Source #

getFacts :: (Fact a, ContainsOutputFact prog a, CollectFacts (ExceptT e m) c) => Handler (ExceptT e m) prog -> ExceptT e m (c a) Source #

findFact :: (Fact a, ContainsOutputFact prog a, Eq a) => Handler (ExceptT e m) prog -> a -> ExceptT e m (Maybe a) Source #

addFact :: (Fact a, ContainsInputFact prog a) => Handler (ExceptT e m) prog -> a -> ExceptT e m () Source #

addFacts :: (Foldable t, Fact a, ContainsInputFact prog a) => Handler (ExceptT e m) prog -> t a -> ExceptT e m () Source #

MonadSouffle m => MonadSouffle (StateT s m) Source # 
Instance details

Defined in Language.Souffle.Class

Associated Types

type Handler (StateT s m) :: Type -> Type Source #

type CollectFacts (StateT s m) c :: Constraint Source #

Methods

run :: Handler (StateT s m) prog -> StateT s m () Source #

setNumThreads :: Handler (StateT s m) prog -> Word64 -> StateT s m () Source #

getNumThreads :: Handler (StateT s m) prog -> StateT s m Word64 Source #

getFacts :: (Fact a, ContainsOutputFact prog a, CollectFacts (StateT s m) c) => Handler (StateT s m) prog -> StateT s m (c a) Source #

findFact :: (Fact a, ContainsOutputFact prog a, Eq a) => Handler (StateT s m) prog -> a -> StateT s m (Maybe a) Source #

addFact :: (Fact a, ContainsInputFact prog a) => Handler (StateT s m) prog -> a -> StateT s m () Source #

addFacts :: (Foldable t, Fact a, ContainsInputFact prog a) => Handler (StateT s m) prog -> t a -> StateT s m () Source #

(Monoid w, MonadSouffle m) => MonadSouffle (WriterT w m) Source # 
Instance details

Defined in Language.Souffle.Class

Associated Types

type Handler (WriterT w m) :: Type -> Type Source #

type CollectFacts (WriterT w m) c :: Constraint Source #

Methods

run :: Handler (WriterT w m) prog -> WriterT w m () Source #

setNumThreads :: Handler (WriterT w m) prog -> Word64 -> WriterT w m () Source #

getNumThreads :: Handler (WriterT w m) prog -> WriterT w m Word64 Source #

getFacts :: (Fact a, ContainsOutputFact prog a, CollectFacts (WriterT w m) c) => Handler (WriterT w m) prog -> WriterT w m (c a) Source #

findFact :: (Fact a, ContainsOutputFact prog a, Eq a) => Handler (WriterT w m) prog -> a -> WriterT w m (Maybe a) Source #

addFact :: (Fact a, ContainsInputFact prog a) => Handler (WriterT w m) prog -> a -> WriterT w m () Source #

addFacts :: (Foldable t, Fact a, ContainsInputFact prog a) => Handler (WriterT w m) prog -> t a -> WriterT w m () Source #

MonadSouffle m => MonadSouffle (ReaderT r m) Source # 
Instance details

Defined in Language.Souffle.Class

Associated Types

type Handler (ReaderT r m) :: Type -> Type Source #

type CollectFacts (ReaderT r m) c :: Constraint Source #

Methods

run :: Handler (ReaderT r m) prog -> ReaderT r m () Source #

setNumThreads :: Handler (ReaderT r m) prog -> Word64 -> ReaderT r m () Source #

getNumThreads :: Handler (ReaderT r m) prog -> ReaderT r m Word64 Source #

getFacts :: (Fact a, ContainsOutputFact prog a, CollectFacts (ReaderT r m) c) => Handler (ReaderT r m) prog -> ReaderT r m (c a) Source #

findFact :: (Fact a, ContainsOutputFact prog a, Eq a) => Handler (ReaderT r m) prog -> a -> ReaderT r m (Maybe a) Source #

addFact :: (Fact a, ContainsInputFact prog a) => Handler (ReaderT r m) prog -> a -> ReaderT r m () Source #

addFacts :: (Foldable t, Fact a, ContainsInputFact prog a) => Handler (ReaderT r m) prog -> t a -> ReaderT r m () Source #

(MonadSouffle m, Monoid w) => MonadSouffle (RWST r w s m) Source # 
Instance details

Defined in Language.Souffle.Class

Associated Types

type Handler (RWST r w s m) :: Type -> Type Source #

type CollectFacts (RWST r w s m) c :: Constraint Source #

Methods

run :: Handler (RWST r w s m) prog -> RWST r w s m () Source #

setNumThreads :: Handler (RWST r w s m) prog -> Word64 -> RWST r w s m () Source #

getNumThreads :: Handler (RWST r w s m) prog -> RWST r w s m Word64 Source #

getFacts :: (Fact a, ContainsOutputFact prog a, CollectFacts (RWST r w s m) c) => Handler (RWST r w s m) prog -> RWST r w s m (c a) Source #

findFact :: (Fact a, ContainsOutputFact prog a, Eq a) => Handler (RWST r w s m) prog -> a -> RWST r w s m (Maybe a) Source #

addFact :: (Fact a, ContainsInputFact prog a) => Handler (RWST r w s m) prog -> a -> RWST r w s m () Source #

addFacts :: (Foldable t, Fact a, ContainsInputFact prog a) => Handler (RWST r w s m) prog -> t a -> RWST r w s m () Source #

class MonadSouffle m => MonadSouffleFileIO m where Source #

A mtl-style typeclass for Souffle-related actions that involve file IO.

Methods

loadFiles :: Handler m prog -> FilePath -> m () Source #

Load all facts from files in a certain directory.

writeFiles :: Handler m prog -> FilePath -> m () Source #

Write out all facts of the program to CSV files in a certain directory (as defined in the Souffle program).

Instances
MonadSouffleFileIO SouffleM Source # 
Instance details

Defined in Language.Souffle.Compiled

MonadSouffleFileIO m => MonadSouffleFileIO (ExceptT s m) Source # 
Instance details

Defined in Language.Souffle.Class

Methods

loadFiles :: Handler (ExceptT s m) prog -> FilePath -> ExceptT s m () Source #

writeFiles :: Handler (ExceptT s m) prog -> FilePath -> ExceptT s m () Source #

MonadSouffleFileIO m => MonadSouffleFileIO (StateT s m) Source # 
Instance details

Defined in Language.Souffle.Class

Methods

loadFiles :: Handler (StateT s m) prog -> FilePath -> StateT s m () Source #

writeFiles :: Handler (StateT s m) prog -> FilePath -> StateT s m () Source #

(Monoid w, MonadSouffleFileIO m) => MonadSouffleFileIO (WriterT w m) Source # 
Instance details

Defined in Language.Souffle.Class

Methods

loadFiles :: Handler (WriterT w m) prog -> FilePath -> WriterT w m () Source #

writeFiles :: Handler (WriterT w m) prog -> FilePath -> WriterT w m () Source #

MonadSouffleFileIO m => MonadSouffleFileIO (ReaderT r m) Source # 
Instance details

Defined in Language.Souffle.Class

Methods

loadFiles :: Handler (ReaderT r m) prog -> FilePath -> ReaderT r m () Source #

writeFiles :: Handler (ReaderT r m) prog -> FilePath -> ReaderT r m () Source #

(MonadSouffleFileIO m, Monoid w) => MonadSouffleFileIO (RWST r w s m) Source # 
Instance details

Defined in Language.Souffle.Class

Methods

loadFiles :: Handler (RWST r w s m) prog -> FilePath -> RWST r w s m () Source #

writeFiles :: Handler (RWST r w s m) prog -> FilePath -> RWST r w s m () Source #