-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Text transformer and interpreter.
--   
@package transf
@version 0.13.1

module Text.Transf

-- | A single line of text.
type Line = String

-- | Multiple lines of text.
type Lines = String

-- | A relative file path.
type RelativePath = FilePath

-- | The <a>Context</a> monad defines the context of a transformation.
--   
--   The main purpose of this type is to restrict the the number of
--   functions you can pass to <a>transform</a>.
type Context = ContextT IO
data ContextT m a

-- | Run a computation in the <a>Context</a> monad.
runContext :: Context a -> IO (Either String a)
runContextT :: Monad m => ContextT m a -> m (Either String a)

-- | A transformation.
data Transform

-- | Create a new transformation.
--   
--   This transformation processes everything in between lines containing a
--   fence such as
--   
--   <pre>
--   ~~~name
--   ~~~
--   </pre>
--   
--   or
--   
--   <pre>
--   ```name
--   ```
--   </pre>
--   
--   where <tt>name</tt> is the name of the transformation.
--   
--   To create a suitable change function, use the combinators defined
--   below.
transform :: String -> (Lines -> Context Lines) -> Transform

-- | Run a transformation in the <a>Context</a> monad.
runTransform :: Transform -> String -> Context String

-- | Read a file.
readFile :: RelativePath -> Context String

-- | Write to a file.
writeFile :: RelativePath -> String -> Context ()

-- | Write to the standard error stream.
inform :: String -> Context ()

-- | Evaluate a Haskell expression.
eval :: Typeable a => String -> Context a

-- | Evaluate a Haskell expression with the given modules in scope. Note
--   that <a>Prelude</a> is <i>not</i> implicitly imported.
--   
--   All requested modules must be present on the system or the computation
--   will fail. Also, the string must be a valid Haskell expression using
--   constructs which in scope after loading the given modules.
--   
--   Errors can be caught using <a>catchError</a>.
evalWith :: Typeable a => [String] -> String -> Context a

-- | Register an action to be run after text processing has finished. This
--   can be used to optimize tasks such as external file generations.
--   
--   Note that addPost does not work trasitively, i.e. post actions of post
--   actions are thrown away.
addPost :: Context () -> Context ()

-- | This named transformation posts its input to the standard error stream
--   and returns nothing.
printT :: Transform

-- | This named transformation evaluates its input as a Haskell expression
--   of type <a>String</a> and returns the value of the expression.
--   
--   For example the input
--   
--   <pre>
--   ~~~haskell
--   "The number is " ++ show $ 3 + 2
--   ~~~
--   </pre>
--   
--   Will be transformed into
--   
--   <pre>
--   The number is 6
--   </pre>
evalT :: Transform

-- | This named transformation evaluates its input as a music expression.
--   
--   The music is rendered as an <tt>.ly</tt> file and a <tt>.mid</tt>
--   fiel, then <tt>lilypond</tt> and <tt>convert</tt> is run to render a
--   <tt>.png</tt> file. A markdown image tag and a HTML play and stop
--   button is returned.
--   
--   The expression must return a value of type <tt>Score Note</tt>. The
--   <a>Music.Prelude.Basic</a> module is implicitly imported.
musicT :: Transform
data MusicOpts
MusicOpts :: String -> Int -> Int -> String -> MusicOpts
format :: MusicOpts -> String
resolution :: MusicOpts -> Int
resize :: MusicOpts -> Int
prelude :: MusicOpts -> String
musicT' :: MusicOpts -> Transform

-- | This named transformation passes everything through and retains the
--   source.
haskellT :: Transform
evalHaskellT :: Transform

-- | This named transformation runs the <tt>music</tt> transformation and
--   retains the source.
musicHaskellT :: Transform
musicHaskellT' :: MusicOpts -> Transform

-- | This named transformation includes stuff needed for music playback.
--   
--   It should be used exactly once in the document.
musicExtraT :: Transform
instance Functor m => Functor (ContextT m)
instance Monad m => Monad (ContextT m)
instance MonadIO m => MonadIO (ContextT m)
instance Monad m => MonadPlus (ContextT m)
instance (Monad m, Functor m) => Applicative (ContextT m)
instance (Monad m, Functor m) => Alternative (ContextT m)
instance Monad m => MonadError String (ContextT m)
instance Monad m => MonadWriter (Post m) (ContextT m)
instance Monoid (Post m)
instance Default MusicOpts
instance Monoid Transform
instance Semigroup Transform

module Text.Transf.Process

-- | Creates a Unix style text processor from a <a>Transform</a>.
--   
--   The resulting action should be used as the main of an application and
--   will render a program of the given name that responds to <tt>-v</tt>
--   and <tt>-h</tt> flags. If given no flags it runs the text transformer
--   over the standard input and output streams. If an error occurs the
--   program halts and prints an error message to the standard error
--   stream.
--   
--   <pre>
--   defaultMain name transf
--   </pre>
defaultMain :: String -> Transform -> IO ()

-- | Like <a>defaultMain</a>, but customizes the transform based on the
--   given options.
--   
--   The <tt>help</tt> and <tt>version</tt> flags are added automatically.
--   
--   <pre>
--   defaultMain' name opts transf
--   </pre>
defaultMain' :: String -> [OptDescr a] -> ([a] -> Transform) -> IO ()
instance Eq (UserOpt a)