Safe Haskell	Safe
Language	Haskell2010

Language.Haskell.TH.QuasiQuoter

Synopsis

data QuasiQuoter = QuasiQuoter {
- quoteExp :: String -> Q Exp
- quotePat :: String -> Q Pat
- quoteType :: String -> Q Type
- quoteDec :: String -> Q [Dec]
}
namedDefaultQuasiQuoter :: String -> QuasiQuoter
defaultQuasiQuoter :: QuasiQuoter
data Q a
data Exp
data Pat
data Type
data Dec

Documentation

data QuasiQuoter #

The QuasiQuoter type, a value q of this type can be used in the syntax [q| ... string to parse ...|]. In fact, for convenience, a QuasiQuoter actually defines multiple quasiquoters to be used in different splice contexts; if you are only interested in defining a quasiquoter to be used for expressions, you would define a QuasiQuoter with only quoteExp, and leave the other fields stubbed out with errors.

Constructors

QuasiQuoter
Fields quoteExp :: String -> Q Exp Quasi-quoter for expressions, invoked by quotes like `lhs = $[q\|...]` quotePat :: String -> Q Pat Quasi-quoter for patterns, invoked by quotes like `f $[q\|...] = rhs` quoteType :: String -> Q Type Quasi-quoter for types, invoked by quotes like `f :: $[q\|...]` quoteDec :: String -> Q [Dec] Quasi-quoter for declarations, invoked by top-level quotes

namedDefaultQuasiQuoter :: String -> QuasiQuoter Source #

A QuasiQuoter that fails with a helpful error message in every context. It is intended to be modified to create a QuasiQuoter that fails in all inappropriate contexts.

For example, you could write

myPatQQ = (namedDefaultQuasiQuoter "myPatQQ")
  { quotePat = ... }

If myPatQQ is used in an expression context, the compiler will report that, naming myPatQQ.

See also defaultQuasiQuoter, which does not name the QuasiQuoter in the error message, and might therefore be more appropriate when the users of a particular QuasiQuoter tend to define local "synonyms" for it.

defaultQuasiQuoter :: QuasiQuoter Source #

A QuasiQuoter that fails with a helpful error message in every context. It is intended to be modified to create a QuasiQuoter that fails in all inappropriate contexts.

For example, you could write

myExpressionQQ = defaultQuasiQuoter
  { quoteExp = ... }

See also namedDefaultQuasiQuoter, which names the QuasiQuoter in the error messages.

data Q a #

In short, Q provides the Quasi operations in one neat monad for the user.

The longer story, is that Q wraps an arbitrary Quasi-able monad. The perceptive reader notices that Quasi has only two instances, Q itself and IO, neither of which have concrete implementations.Q plays the trick of dependency inversion, providing an abstract interface for the user which is later concretely fufilled by an concrete Quasi instance, internal to GHC.

Instances

Instances details

Applicative Q #
Instance details Defined in GHC.Internal.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 #
Functor Q #
Instance details Defined in GHC.Internal.TH.Syntax Methods fmap :: (a -> b) -> Q a -> Q b # (<$) :: a -> Q b -> Q a #
Monad Q #
Instance details Defined in GHC.Internal.TH.Syntax Methods (>>=) :: Q a -> (a -> Q b) -> Q b # (>>) :: Q a -> Q b -> Q b # return :: a -> Q a #
MonadFail Q #
Instance details Defined in GHC.Internal.TH.Syntax Methods fail :: String -> Q a #
MonadFix Q #	If the function passed to `mfix` inspects its argument, the resulting action will throw a `FixIOException`. Since: ghc-internal-2.17.0.0
Instance details Defined in GHC.Internal.TH.Syntax Methods mfix :: (a -> Q a) -> Q a #
MonadIO Q #
Instance details Defined in GHC.Internal.TH.Syntax Methods liftIO :: IO a -> Q a #
Quasi Q #
Instance details Defined in GHC.Internal.TH.Syntax Methods qNewName :: String -> Q Name # qReport :: Bool -> String -> Q () # qRecover :: Q a -> Q a -> Q a # qLookupName :: Bool -> String -> Q (Maybe Name) # qReify :: Name -> Q Info # qReifyFixity :: Name -> Q (Maybe Fixity) # qReifyType :: Name -> Q Type # qReifyInstances :: Name -> [Type] -> Q [Dec] # qReifyRoles :: Name -> Q [Role] # qReifyAnnotations :: Data a => AnnLookup -> Q [a] # qReifyModule :: Module -> Q ModuleInfo # qReifyConStrictness :: Name -> Q [DecidedStrictness] # qLocation :: Q Loc # qRunIO :: IO a -> Q a # qGetPackageRoot :: Q FilePath # qAddDependentFile :: FilePath -> Q () # qAddTempFile :: String -> Q FilePath # qAddTopDecls :: [Dec] -> Q () # qAddForeignFilePath :: ForeignSrcLang -> String -> Q () # qAddModFinalizer :: Q () -> Q () # qAddCorePlugin :: String -> Q () # qGetQ :: Typeable a => Q (Maybe a) # qPutQ :: Typeable a => a -> Q () # qIsExtEnabled :: Extension -> Q Bool # qExtsEnabled :: Q [Extension] # qPutDoc :: DocLoc -> String -> Q () # qGetDoc :: DocLoc -> Q (Maybe String) #
Quote Q #
Instance details Defined in GHC.Internal.TH.Syntax Methods newName :: String -> Q Name #
Monoid a => Monoid (Q a) #	Since: ghc-internal-2.17.0.0
Instance details Defined in GHC.Internal.TH.Syntax Methods mempty :: Q a # mappend :: Q a -> Q a -> Q a # mconcat :: [Q a] -> Q a #
Semigroup a => Semigroup (Q a) #	Since: ghc-internal-2.17.0.0
Instance details Defined in GHC.Internal.TH.Syntax Methods (<>) :: Q a -> Q a -> Q a # sconcat :: NonEmpty (Q a) -> Q a # stimes :: Integral b => b -> Q a -> Q a #

data Exp #

A Haskell expression.

Instances

Instances details

Data Exp #

Instance details