The Quipper System

Safe HaskellNone

Quipper.Utils.Template

Contents

Description

This module provides the public interface to the template lifting library. It provides functions that input a Haskell declaration or expression (in the form of a Haskell abstract syntax tree), and lift this to another declaration or expression, with all functions lifted into a specified monad.

This can be combined with Template Haskell to convert source code to Haskell abstract syntax trees and vice versa.

Synopsis

Example

We give an example to illustrate what is meant by "lifting" a term to a monad. Consider the expression

f = \g x -> g x x,

which has type

f :: (a -> a -> b) -> (a -> b).

We can lift this to the IO monad by

  • converting the expression to an abstract syntax tree, using the special Template Haskell notation [| ... |];
  • applying the expToMonad function;
  • converting the resulting abstract syntax tree back to a term, using the special Template Haskell notation $( ... ).

This allows us to write the following:

f' = $( expToMonad "IO" [| \\g x -> g x x |] ),

which has type

f' :: IO ((a -> IO (a -> IO b)) -> IO (a -> IO b)),

and is in fact equivalent to

f'' = return $ \g ->
        return $ \x -> do
          h <- g x
          y <- h x
          return y

General lifting functions

decToMonad :: String -> Q [Dec] -> Q [Dec] Source #

Lift a list of declarations. The first argument is the name of the monad to lift into.

expToMonad :: String -> Q Exp -> Q Exp Source #

Lift an expression. The first argument is the name of the monad to lift into.

Liftings of specific constants

Re-exports from Language.Haskell.TH.

data Q a #

Instances
Monad Q 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

(>>=) :: Q a -> (a -> Q b) -> Q b #

(>>) :: Q a -> Q b -> Q b #

return :: a -> Q a #

fail :: String -> Q a #

Functor Q 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

fmap :: (a -> b) -> Q a -> Q b #

(<$) :: a -> Q b -> Q a #

MonadFail Q 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

fail :: String -> Q a #

Applicative Q 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

pure :: a -> Q a #

(<*>) :: Q (a -> b) -> Q a -> Q b #

liftA2 :: (a -> b -> c) -> Q a -> Q b -> Q c #

(*>) :: Q a -> Q b -> Q b #

(<*) :: Q a -> Q b -> Q a #

MonadIO Q 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

liftIO :: IO a -> Q a #

Quasi Q 
Instance details

Defined in Language.Haskell.TH.Syntax

data Dec #

Instances
Eq Dec 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

(==) :: Dec -> Dec -> Bool #

(/=) :: Dec -> Dec -> Bool #

Data Dec 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Dec -> c Dec #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Dec #

toConstr :: Dec -> Constr #

dataTypeOf :: Dec -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Dec) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Dec) #

gmapT :: (forall b. Data b => b -> b) -> Dec -> Dec #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Dec -> r #

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Dec -> r #

gmapQ :: (forall d. Data d => d -> u) -> Dec -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Dec -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Dec -> m Dec #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Dec -> m Dec #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Dec -> m Dec #

Ord Dec 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

compare :: Dec -> Dec -> Ordering #

(<) :: Dec -> Dec -> Bool #

(<=) :: Dec -> Dec -> Bool #

(>) :: Dec -> Dec -> Bool #

(>=) :: Dec -> Dec -> Bool #

max :: Dec -> Dec -> Dec #

min :: Dec -> Dec -> Dec #

Show Dec 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

showsPrec :: Int -> Dec -> ShowS #

show :: Dec -> String #

showList :: [Dec] -> ShowS #

Generic Dec 
Instance details

Defined in Language.Haskell.TH.Syntax

Associated Types

type Rep Dec :: Type -> Type #

Methods

from :: Dec -> Rep Dec x #

to :: Rep Dec x -> Dec #

Ppr Dec 
Instance details

Defined in Language.Haskell.TH.Ppr

Methods

ppr :: Dec -> Doc #

ppr_list :: [Dec] -> Doc #

type Rep Dec 
Instance details

Defined in Language.Haskell.TH.Syntax

type Rep Dec = D1 (MetaData "Dec" "Language.Haskell.TH.Syntax" "template-haskell" False) ((((C1 (MetaCons "FunD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Clause])) :+: C1 (MetaCons "ValD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Pat) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Body) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Dec])))) :+: (C1 (MetaCons "DataD" PrefixI False) ((S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Cxt) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [TyVarBndr]))) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Kind)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Con]) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [DerivClause])))) :+: (C1 (MetaCons "NewtypeD" PrefixI False) ((S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Cxt) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [TyVarBndr]))) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Kind)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Con) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [DerivClause])))) :+: C1 (MetaCons "TySynD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [TyVarBndr]) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Type)))))) :+: ((C1 (MetaCons "ClassD" PrefixI False) ((S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Cxt) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [TyVarBndr]) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [FunDep]) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Dec])))) :+: (C1 (MetaCons "InstanceD" PrefixI False) ((S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Overlap)) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Cxt)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Type) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Dec]))) :+: C1 (MetaCons "SigD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Type)))) :+: (C1 (MetaCons "ForeignD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Foreign)) :+: (C1 (MetaCons "InfixD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Fixity) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name)) :+: C1 (MetaCons "PragmaD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Pragma)))))) :+: (((C1 (MetaCons "DataFamilyD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [TyVarBndr]) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Kind)))) :+: C1 (MetaCons "DataInstD" PrefixI False) ((S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Cxt) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Type]))) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Kind)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Con]) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [DerivClause]))))) :+: (C1 (MetaCons "NewtypeInstD" PrefixI False) ((S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Cxt) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Type]))) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Kind)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Con) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [DerivClause])))) :+: (C1 (MetaCons "TySynInstD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 TySynEqn)) :+: C1 (MetaCons "OpenTypeFamilyD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 TypeFamilyHead))))) :+: ((C1 (MetaCons "ClosedTypeFamilyD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 TypeFamilyHead) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [TySynEqn])) :+: (C1 (MetaCons "RoleAnnotD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Role])) :+: C1 (MetaCons "StandaloneDerivD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe DerivStrategy)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Cxt) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Type))))) :+: (C1 (MetaCons "DefaultSigD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Type)) :+: (C1 (MetaCons "PatSynD" PrefixI False) ((S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 PatSynArgs)) :*: (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 PatSynDir) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Pat))) :+: C1 (MetaCons "PatSynSigD" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Name) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 PatSynType)))))))