Hpp.Types

The core types involved used by the pre-processor.

Documentation

type LineNum = Int

Line numbers are represented as Ints

type Env = HashMap ByteString Macro

A macro binding environment.

Changing the underlying string type

type String = ByteString

type TOKEN = Token ByteString

Errors

data Error

Error conditions we may encounter.

Constructors

UnterminatedBranch

BadMacroDefinition LineNum

BadIfPredicate

BadLineArgument LineNum String

IncludeDoesNotExist LineNum FilePath

FailedInclude LineNum FilePath

UserError LineNum String

UnknownCommand LineNum String

TooFewArgumentsToMacro LineNum String

BadMacroArguments LineNum String

NoInputFile

BadCommandLine String

RanOutOfInput

Instances

Eq Error

Defined in Hpp.Types

Methods

(==) :: Error -> Error -> Bool

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

Ord Error

Defined in Hpp.Types

Methods

compare :: Error -> Error -> Ordering

(<) :: Error -> Error -> Bool

(<=) :: Error -> Error -> Bool

(>) :: Error -> Error -> Bool

(>=) :: Error -> Error -> Bool

max :: Error -> Error -> Error

min :: Error -> Error -> Error

Show Error

Defined in Hpp.Types

Methods

showsPrec :: Int -> Error -> ShowS

show :: Error -> String

showList :: [Error] -> ShowS

Exception Error

Defined in Hpp.Types

Methods

toException :: Error -> SomeException

fromException :: SomeException -> Maybe Error

displayException :: Error -> String

Monad m => HasError (ExceptT Error m)

Defined in Hpp.Types

Methods

throwError :: Error -> ExceptT Error m a

class HasError m where

Hpp can raise various parsing errors.

Methods

throwError :: Error -> m a

Instances

(Monad m, HasError m) => HasError (StateT s m)

Defined in Hpp.Types

Methods

throwError :: Error -> StateT s m a

Monad m => HasError (ExceptT Error m)

Defined in Hpp.Types

Methods

throwError :: Error -> ExceptT Error m a

(Monad m, HasError m) => HasError (HppT t m)

Defined in Hpp.Types

Methods

throwError :: Error -> HppT t m a

Free Monad Transformers

data FreeF f a r

Base functor for a free monad transformer

Constructors

PureF a

FreeF (f r)

Instances

Functor f => Functor (FreeF f a)

Defined in Hpp.Types

Methods

fmap :: (a0 -> b) -> FreeF f a a0 -> FreeF f a b

(<$) :: a0 -> FreeF f a b -> FreeF f a a0

Pre-processor Actions

data HppState

Dynamic state of the preprocessor engine.

Constructors

HppState

Fields

• hppConfig :: Config

  Initial configuration

• hppCurDir :: FilePath

  Directory of input file

• hppLineNum :: LineNum

  Current line number of input file

• hppEnv :: Env

  Preprocessor binding environment

Instances

Show HppState

Defined in Hpp.Types

Methods

showsPrec :: Int -> HppState -> ShowS

show :: HppState -> String

showList :: [HppState] -> ShowS

Monad m => HasEnv (StateT HppState m)

Defined in Hpp.Types

Methods

getEnv :: StateT HppState m Env

setEnv :: Env -> StateT HppState m ()

Monad m => HasHppState (StateT HppState m)

Defined in Hpp.Types

Methods

getState :: StateT HppState m HppState

setState :: HppState -> StateT HppState m ()

data HppF t r

A free monad construction to strictly delimit what capabilities we need to perform pre-processing.

Constructors

ReadFile Int FilePath (t -> r)

ReadNext Int FilePath (t -> r)

WriteOutput t r

Instances

Functor (HppF t)

Defined in Hpp.Types

Methods

fmap :: (a -> b) -> HppF t a -> HppF t b

(<$) :: a -> HppF t b -> HppF t a

type Hpp t = FreeF (HppF t)

Hpp is a monad with HppF as its base functor.

Hpp Monad Transformer

newtype HppT t m a

A free monad transformer specialized to HppF as the base functor.

Constructors

HppT

Fields

• runHppT :: m (Hpp t a (HppT t m a))

Instances

MonadTrans (HppT t)

Defined in Hpp.Types

Methods

lift :: Monad m => m a -> HppT t m a

Monad m => Monad (HppT t m)

Defined in Hpp.Types

Methods

(>>=) :: HppT t m a -> (a -> HppT t m b) -> HppT t m b

(>>) :: HppT t m a -> HppT t m b -> HppT t m b

return :: a -> HppT t m a

Functor m => Functor (HppT t m)

Defined in Hpp.Types

Methods

fmap :: (a -> b) -> HppT t m a -> HppT t m b

(<$) :: a -> HppT t m b -> HppT t m a

Monad m => Applicative (HppT t m)

Defined in Hpp.Types

Methods

pure :: a -> HppT t m a

(<*>) :: HppT t m (a -> b) -> HppT t m a -> HppT t m b

liftA2 :: (a -> b -> c) -> HppT t m a -> HppT t m b -> HppT t m c

(*>) :: HppT t m a -> HppT t m b -> HppT t m b

(<*) :: HppT t m a -> HppT t m b -> HppT t m a

MonadIO m => MonadIO (HppT t m)

Defined in Hpp.Types

Methods

liftIO :: IO a -> HppT t m a

(Monad m, HasHppState m) => HasEnv (HppT t m)

Defined in Hpp.Types

Methods

getEnv :: HppT t m Env

setEnv :: Env -> HppT t m ()

(Monad m, HasHppState m) => HasHppState (HppT t m)

Defined in Hpp.Types

Methods

getState :: HppT t m HppState

setState :: HppState -> HppT t m ()

(Monad m, HasError m) => HasError (HppT t m)

Defined in Hpp.Types

Methods

throwError :: Error -> HppT t m a

hppReadFile :: Monad m => Int -> FilePath -> HppT src m src

hppReadFile lineNumber fileName introduces an #include fileName at the given line number.

hppReadNext :: Monad m => Int -> FilePath -> HppT src m src

hppReadNext lineNumber fileName introduces an #include_next fileName at the given line number.

hppWriteOutput :: Monad m => t -> HppT t m ()

class HasHppState m where

An interpreter capability to modify dynamic state.

Methods

getState :: m HppState

setState :: HppState -> m ()

Instances

(Monad m, HasHppState m) => HasHppState (StateT s m)

Defined in Hpp.Types

Methods

getState :: StateT s m HppState

setState :: HppState -> StateT s m ()

Monad m => HasHppState (StateT HppState m)

Defined in Hpp.Types

Methods

getState :: StateT HppState m HppState

setState :: HppState -> StateT HppState m ()

(Monad m, HasHppState m) => HasHppState (ExceptT e m)

Defined in Hpp.Types

Methods

getState :: ExceptT e m HppState

setState :: HppState -> ExceptT e m ()

(Monad m, HasHppState m) => HasHppState (HppT t m)

Defined in Hpp.Types

Methods

getState :: HppT t m HppState

setState :: HppState -> HppT t m ()

class HasEnv m where

An interpreter capability of threading a binding environment.

Methods

getEnv :: m Env

setEnv :: Env -> m ()

Instances

Monad m => HasEnv (StateT HppState m)

Defined in Hpp.Types

Methods

getEnv :: StateT HppState m Env

setEnv :: Env -> StateT HppState m ()

Monad m => HasEnv (StateT Env m)

Defined in Hpp.Types

Methods

getEnv :: StateT Env m Env

setEnv :: Env -> StateT Env m ()

(HasEnv m, Monad m) => HasEnv (ExceptT e m)

Defined in Hpp.Types

Methods

getEnv :: ExceptT e m Env

setEnv :: Env -> ExceptT e m ()

(Monad m, HasHppState m) => HasEnv (HppT t m)

Defined in Hpp.Types

Methods

getEnv :: HppT t m Env

setEnv :: Env -> HppT t m ()

Expansion

data Scan

Macro expansion involves treating tokens differently if they appear in the original source or as the result of a previous macro expansion. This distinction is used to prevent divergence by masking out definitions that could be used recursively.

Things are made somewhat more complicated than one might expect due to the fact that the scope of this masking is not structurally recursive. A object-like macro can expand into a fragment of a macro function application, one of whose arguments is a token matching the original object-like macro. That argument should not be expanded.

Constructors

Unmask String

Mask String

Scan (Token String)

Rescan (Token String)

Instances

Eq Scan

Defined in Hpp.Types

Methods

(==) :: Scan -> Scan -> Bool

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

Show Scan

Defined in Hpp.Types

Methods

showsPrec :: Int -> Scan -> ShowS

show :: Scan -> String

showList :: [Scan] -> ShowS

Macros

data Macro

There are object-like macros and function-like macros.

Constructors

Object [Token String]

An object-like macro is replaced with its definition

Function Int ([([Scan], String)] -> [Scan])

A function-like macro of some arity taks macro-expanded and raw versions of its arguments, then substitutes them into a body producing a new set of tokens.

Instances

Show Macro

Defined in Hpp.Types

Methods

showsPrec :: Int -> Macro -> ShowS

show :: Macro -> String

showList :: [Macro] -> ShowS

Monad m => HasEnv (StateT Env m)

Defined in Hpp.Types

Methods

getEnv :: StateT Env m Env

setEnv :: Env -> StateT Env m ()

lookupMacro :: (HasEnv m, Monad m) => String -> m (Maybe Macro)

Looks up a Macro in the current environment. If the Macro is found, the environment is juggled so that subsequent lookups of the same Macro may evaluate more quickly.

Nano-lens

type Lens s a = forall f. Functor f => (a -> f a) -> s -> f s

setL :: Lens s a -> a -> s -> s

getL :: Lens s a -> s -> a

over :: Lens s a -> (a -> a) -> s -> s

State Lenses

emptyHppState :: Config -> HppState

config :: Lens HppState Config

dir :: Lens HppState FilePath

lineNum :: Lens HppState LineNum

env :: Lens HppState Env

use :: (HasHppState m, Functor m) => Lens HppState a -> m a

(.=) :: (HasHppState m, Monad m) => Lens HppState a -> a -> m () infix 4

(%=) :: (HasHppState m, Monad m) => Lens HppState a -> (a -> a) -> m () infix 4