{-# LANGUAGE CApiFFI #-}
{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE Trustworthy #-}
-- |
-- Maintainer  : judah.jacobson@gmail.com
-- Stability   : experimental
-- Portability : portable (FFI)
--
-- This module provides a low-level interface to the C functions of the 
-- terminfo library. 
-- 
-- NOTE: Since this library is built on top of the curses interface, it is not thread-safe.

module System.Console.Terminfo.Base(
                            -- *  Initialization
                            Terminal(),
                            setupTerm,
                            setupTermFromEnv,
                            SetupTermError,
                            -- * Capabilities
                            Capability,
                            getCapability,
                            tiGetFlag,
                            tiGuardFlag,
                            tiGetNum,
                            tiGetStr,
                            -- * Output
                            -- $outputdoc
                            tiGetOutput1,
                            OutputCap,
                            TermStr,
                            -- ** TermOutput
                            TermOutput(),
                            runTermOutput,
                            hRunTermOutput,
                            termText,
                            tiGetOutput,
                            LinesAffected,
                            -- ** Monoid functions
                            Monoid(..),
                            (<#>),
                            ) where


import Control.Applicative
import Control.Monad
import Data.Semigroup as Sem (Semigroup(..))
import Foreign.C
import Foreign.ForeignPtr
import Foreign.Ptr
import Foreign.Marshal
import Foreign.Storable (peek)
import System.Environment (getEnv)
import System.IO.Unsafe (unsafePerformIO)
import System.IO
import Control.Exception
import Data.Typeable


data TERMINAL

-- | 'Terminal' objects are automatically freed by the garbage collector.
--   Hence, there is no equivalent of @del_curterm@ here.
newtype Terminal = Terminal (ForeignPtr TERMINAL)

-- Use "unsafe" to make set_curterm faster since it's called quite a bit.
foreign import ccall unsafe set_curterm :: Ptr TERMINAL -> IO (Ptr TERMINAL)
foreign import ccall "&" del_curterm :: FunPtr (Ptr TERMINAL -> IO ())

foreign import ccall setupterm :: CString -> CInt -> Ptr CInt -> IO ()

-- | Initialize the terminfo library to the given terminal entry.
-- 
-- Throws a 'SetupTermError' if the terminfo database could not be read.
--
-- *Note:* @ncurses@ is not thread-safe; initializing or using multiple
-- 'Terminal's in different threads at the same time can result in memory
-- unsafety.
setupTerm :: String -> IO Terminal
setupTerm :: [Char] -> IO Terminal
setupTerm [Char]
term =
    [Char] -> (Ptr CChar -> IO Terminal) -> IO Terminal
forall a. [Char] -> (Ptr CChar -> IO a) -> IO a
withCString [Char]
term ((Ptr CChar -> IO Terminal) -> IO Terminal)
-> (Ptr CChar -> IO Terminal) -> IO Terminal
forall a b. (a -> b) -> a -> b
$ \Ptr CChar
c_term ->
    CInt -> (Ptr CInt -> IO Terminal) -> IO Terminal
forall a b. Storable a => a -> (Ptr a -> IO b) -> IO b
with CInt
0 ((Ptr CInt -> IO Terminal) -> IO Terminal)
-> (Ptr CInt -> IO Terminal) -> IO Terminal
forall a b. (a -> b) -> a -> b
$ \Ptr CInt
ret_ptr -> do
        -- NOTE: I believe that for the way we use terminfo
        -- (i.e. custom output function)
        -- this parameter does not affect anything.
        let stdOutput :: CInt
stdOutput = CInt
1
        -- Save the previous terminal to be restored after calling setupterm.
        old_term <- Ptr TERMINAL -> IO (Ptr TERMINAL)
set_curterm Ptr TERMINAL
forall a. Ptr a
nullPtr
        -- Call setupterm and check the return value.
        setupterm c_term stdOutput ret_ptr
        ret <- peek ret_ptr
        if (ret /=1)
            then throwIO $ SetupTermError
                $ "Couldn't look up terminfo entry " ++ show term
            else do
                cterm <- set_curterm old_term
                fmap Terminal $ newForeignPtr del_curterm cterm

data SetupTermError = SetupTermError String
                        deriving Typeable

instance Show SetupTermError where
    show :: SetupTermError -> [Char]
show (SetupTermError [Char]
str) = [Char]
"setupTerm: " [Char] -> [Char] -> [Char]
forall a. [a] -> [a] -> [a]
++ [Char]
str

instance Exception SetupTermError where

-- | Initialize the terminfo library, using the @TERM@ environmental variable.
-- If @TERM@ is not set, we use the generic, minimal entry @dumb@.
-- 
-- Throws a 'SetupTermError' if the terminfo database could not be read.
setupTermFromEnv :: IO Terminal
setupTermFromEnv :: IO Terminal
setupTermFromEnv = do
    env_term <- (IOException -> IO [Char]) -> IO [Char] -> IO [Char]
forall e a. Exception e => (e -> IO a) -> IO a -> IO a
handle IOException -> IO [Char]
handleBadEnv (IO [Char] -> IO [Char]) -> IO [Char] -> IO [Char]
forall a b. (a -> b) -> a -> b
$ [Char] -> IO [Char]
getEnv [Char]
"TERM" 
    let term = if [Char] -> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [Char]
env_term then [Char]
"dumb" else [Char]
env_term
    setupTerm term
  where
    handleBadEnv :: IOException -> IO String
    handleBadEnv :: IOException -> IO [Char]
handleBadEnv IOException
_ = [Char] -> IO [Char]
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return [Char]
""

-- TODO: this isn't really thread-safe...
withCurTerm :: Terminal -> IO a -> IO a
withCurTerm :: forall a. Terminal -> IO a -> IO a
withCurTerm (Terminal ForeignPtr TERMINAL
term) IO a
f = ForeignPtr TERMINAL -> (Ptr TERMINAL -> IO a) -> IO a
forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr TERMINAL
term ((Ptr TERMINAL -> IO a) -> IO a) -> (Ptr TERMINAL -> IO a) -> IO a
forall a b. (a -> b) -> a -> b
$ \Ptr TERMINAL
cterm -> do
        old_term <- Ptr TERMINAL -> IO (Ptr TERMINAL)
set_curterm Ptr TERMINAL
cterm
        x <- f
        _ <- set_curterm old_term
        return x


----------------------

-- Note I'm relying on this working even for strings with unset parameters.
strHasPadding :: String -> Bool
strHasPadding :: [Char] -> Bool
strHasPadding [] = Bool
False
strHasPadding (Char
'$':Char
'<':[Char]
_) = Bool
True
strHasPadding (Char
_:[Char]
cs) = [Char] -> Bool
strHasPadding [Char]
cs

-- | An action which sends output to the terminal.  That output may mix plain text with control
-- characters and escape sequences, along with delays (called \"padding\") required by some older
-- terminals.

-- We structure this similarly to ShowS, so that appends don't cause space leaks.
newtype TermOutput = TermOutput ([TermOutputType] -> [TermOutputType])

data TermOutputType = TOCmd LinesAffected String
                    | TOStr String

instance Sem.Semigroup TermOutput where
    TermOutput [TermOutputType] -> [TermOutputType]
xs <> :: TermOutput -> TermOutput -> TermOutput
<> TermOutput [TermOutputType] -> [TermOutputType]
ys = ([TermOutputType] -> [TermOutputType]) -> TermOutput
TermOutput ([TermOutputType] -> [TermOutputType]
xs ([TermOutputType] -> [TermOutputType])
-> ([TermOutputType] -> [TermOutputType])
-> [TermOutputType]
-> [TermOutputType]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [TermOutputType] -> [TermOutputType]
ys)

instance Monoid TermOutput where
    mempty :: TermOutput
mempty  = ([TermOutputType] -> [TermOutputType]) -> TermOutput
TermOutput [TermOutputType] -> [TermOutputType]
forall a. a -> a
id
    mappend :: TermOutput -> TermOutput -> TermOutput
mappend = TermOutput -> TermOutput -> TermOutput
forall a. Semigroup a => a -> a -> a
(<>)

termText :: String -> TermOutput 
termText :: [Char] -> TermOutput
termText [Char]
str = ([TermOutputType] -> [TermOutputType]) -> TermOutput
TermOutput ([Char] -> TermOutputType
TOStr [Char]
str TermOutputType -> [TermOutputType] -> [TermOutputType]
forall a. a -> [a] -> [a]
:)

-- | Write the terminal output to the standard output device.
runTermOutput :: Terminal -> TermOutput -> IO ()
runTermOutput :: Terminal -> TermOutput -> IO ()
runTermOutput = Handle -> Terminal -> TermOutput -> IO ()
hRunTermOutput Handle
stdout

-- | Write the terminal output to the terminal or file managed by the given
-- 'Handle'.
hRunTermOutput :: Handle -> Terminal -> TermOutput -> IO ()
hRunTermOutput :: Handle -> Terminal -> TermOutput -> IO ()
hRunTermOutput Handle
h Terminal
term (TermOutput [TermOutputType] -> [TermOutputType]
to) = do
    putc_ptr <- CharOutput -> IO (FunPtr CharOutput)
mkCallback CharOutput
forall {b}. Enum b => b -> IO b
putc
    withCurTerm term $ mapM_ (writeToTerm putc_ptr h) (to [])
    freeHaskellFunPtr putc_ptr
    hFlush h
  where
    putc :: b -> IO b
putc b
c = let c' :: Char
c' = Int -> Char
forall a. Enum a => Int -> a
toEnum (Int -> Char) -> Int -> Char
forall a b. (a -> b) -> a -> b
$ b -> Int
forall a. Enum a => a -> Int
fromEnum b
c
             in Handle -> Char -> IO ()
hPutChar Handle
h Char
c' IO () -> IO () -> IO ()
forall a b. IO a -> IO b -> IO b
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Handle -> IO ()
hFlush Handle
h IO () -> IO b -> IO b
forall a b. IO a -> IO b -> IO b
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> b -> IO b
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return b
c

-- NOTE: Currently, the output is checked every time tparm is called.
-- It might be faster to check for padding once in tiGetOutput1.
writeToTerm :: FunPtr CharOutput -> Handle -> TermOutputType -> IO ()
writeToTerm :: FunPtr CharOutput -> Handle -> TermOutputType -> IO ()
writeToTerm FunPtr CharOutput
putc Handle
h (TOCmd Int
numLines [Char]
s)
    | [Char] -> Bool
strHasPadding [Char]
s = [Char] -> Int -> FunPtr CharOutput -> IO ()
tPuts [Char]
s Int
numLines FunPtr CharOutput
putc
    | Bool
otherwise = Handle -> [Char] -> IO ()
hPutStr Handle
h [Char]
s
writeToTerm FunPtr CharOutput
_ Handle
h (TOStr [Char]
s) = Handle -> [Char] -> IO ()
hPutStr Handle
h [Char]
s

infixl 2 <#>

-- | An operator version of 'mappend'.
(<#>) :: Monoid m => m -> m -> m
<#> :: forall m. Monoid m => m -> m -> m
(<#>) = m -> m -> m
forall m. Monoid m => m -> m -> m
mappend
---------------------------------

-- | A feature or operation which a 'Terminal' may define.
newtype Capability a = Capability (Terminal -> IO (Maybe a))

getCapability :: Terminal -> Capability a -> Maybe a
getCapability :: forall a. Terminal -> Capability a -> Maybe a
getCapability Terminal
term (Capability Terminal -> IO (Maybe a)
f) = IO (Maybe a) -> Maybe a
forall a. IO a -> a
unsafePerformIO (IO (Maybe a) -> Maybe a) -> IO (Maybe a) -> Maybe a
forall a b. (a -> b) -> a -> b
$ Terminal -> IO (Maybe a) -> IO (Maybe a)
forall a. Terminal -> IO a -> IO a
withCurTerm Terminal
term (Terminal -> IO (Maybe a)
f Terminal
term)

-- Note that the instances for Capability of Functor, Monad and MonadPlus 
-- use the corresponding instances for Maybe.
instance Functor Capability where
    fmap :: forall a b. (a -> b) -> Capability a -> Capability b
fmap a -> b
f (Capability Terminal -> IO (Maybe a)
g) = (Terminal -> IO (Maybe b)) -> Capability b
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe b)) -> Capability b)
-> (Terminal -> IO (Maybe b)) -> Capability b
forall a b. (a -> b) -> a -> b
$ \Terminal
t -> (Maybe a -> Maybe b) -> IO (Maybe a) -> IO (Maybe b)
forall a b. (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap ((a -> b) -> Maybe a -> Maybe b
forall a b. (a -> b) -> Maybe a -> Maybe b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap a -> b
f) (Terminal -> IO (Maybe a)
g Terminal
t)

instance Applicative Capability where
    pure :: forall a. a -> Capability a
pure = (Terminal -> IO (Maybe a)) -> Capability a
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe a)) -> Capability a)
-> (a -> Terminal -> IO (Maybe a)) -> a -> Capability a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. IO (Maybe a) -> Terminal -> IO (Maybe a)
forall a b. a -> b -> a
const (IO (Maybe a) -> Terminal -> IO (Maybe a))
-> (a -> IO (Maybe a)) -> a -> Terminal -> IO (Maybe a)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Maybe a -> IO (Maybe a)
forall a. a -> IO a
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Maybe a -> IO (Maybe a)) -> (a -> Maybe a) -> a -> IO (Maybe a)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> Maybe a
forall a. a -> Maybe a
Just
    <*> :: forall a b. Capability (a -> b) -> Capability a -> Capability b
(<*>) = Capability (a -> b) -> Capability a -> Capability b
forall (m :: * -> *) a b. Monad m => m (a -> b) -> m a -> m b
ap

instance Monad Capability where
    return :: forall a. a -> Capability a
return = a -> Capability a
forall a. a -> Capability a
forall (f :: * -> *) a. Applicative f => a -> f a
pure
    Capability Terminal -> IO (Maybe a)
f >>= :: forall a b. Capability a -> (a -> Capability b) -> Capability b
>>= a -> Capability b
g = (Terminal -> IO (Maybe b)) -> Capability b
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe b)) -> Capability b)
-> (Terminal -> IO (Maybe b)) -> Capability b
forall a b. (a -> b) -> a -> b
$ \Terminal
t -> do
        mx <- Terminal -> IO (Maybe a)
f Terminal
t
        case mx of
            Maybe a
Nothing -> Maybe b -> IO (Maybe b)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe b
forall a. Maybe a
Nothing
            Just a
x -> let Capability Terminal -> IO (Maybe b)
g' = a -> Capability b
g a
x in Terminal -> IO (Maybe b)
g' Terminal
t

instance Alternative Capability where
    <|> :: forall a. Capability a -> Capability a -> Capability a
(<|>) = Capability a -> Capability a -> Capability a
forall a. Capability a -> Capability a -> Capability a
forall (m :: * -> *) a. MonadPlus m => m a -> m a -> m a
mplus
    empty :: forall a. Capability a
empty = Capability a
forall a. Capability a
forall (m :: * -> *) a. MonadPlus m => m a
mzero

instance MonadPlus Capability where
    mzero :: forall a. Capability a
mzero = (Terminal -> IO (Maybe a)) -> Capability a
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability (IO (Maybe a) -> Terminal -> IO (Maybe a)
forall a b. a -> b -> a
const (IO (Maybe a) -> Terminal -> IO (Maybe a))
-> IO (Maybe a) -> Terminal -> IO (Maybe a)
forall a b. (a -> b) -> a -> b
$ Maybe a -> IO (Maybe a)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe a
forall a. Maybe a
Nothing)
    Capability Terminal -> IO (Maybe a)
f mplus :: forall a. Capability a -> Capability a -> Capability a
`mplus` Capability Terminal -> IO (Maybe a)
g = (Terminal -> IO (Maybe a)) -> Capability a
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe a)) -> Capability a)
-> (Terminal -> IO (Maybe a)) -> Capability a
forall a b. (a -> b) -> a -> b
$ \Terminal
t -> do
        mx <- Terminal -> IO (Maybe a)
f Terminal
t
        case mx of
            Maybe a
Nothing -> Terminal -> IO (Maybe a)
g Terminal
t
            Maybe a
_ -> Maybe a -> IO (Maybe a)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe a
mx

foreign import ccall tigetnum :: CString -> IO CInt

-- | Look up a numeric capability in the terminfo database.
tiGetNum :: String -> Capability Int 
tiGetNum :: [Char] -> Capability Int
tiGetNum [Char]
cap = (Terminal -> IO (Maybe Int)) -> Capability Int
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe Int)) -> Capability Int)
-> (Terminal -> IO (Maybe Int)) -> Capability Int
forall a b. (a -> b) -> a -> b
$ IO (Maybe Int) -> Terminal -> IO (Maybe Int)
forall a b. a -> b -> a
const (IO (Maybe Int) -> Terminal -> IO (Maybe Int))
-> IO (Maybe Int) -> Terminal -> IO (Maybe Int)
forall a b. (a -> b) -> a -> b
$ do
                n <- (CInt -> Int) -> IO CInt -> IO Int
forall a b. (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap CInt -> Int
forall a. Enum a => a -> Int
fromEnum ([Char] -> (Ptr CChar -> IO CInt) -> IO CInt
forall a. [Char] -> (Ptr CChar -> IO a) -> IO a
withCString [Char]
cap Ptr CChar -> IO CInt
tigetnum)
                if n >= 0
                    then return (Just n)
                    else return Nothing

foreign import ccall tigetflag :: CString -> IO CInt
-- | Look up a boolean capability in the terminfo database.  
-- 
-- Unlike 'tiGuardFlag', this capability never fails; it returns 'False' if the
-- capability is absent or set to false, and returns 'True' otherwise.  
-- 
tiGetFlag :: String -> Capability Bool
tiGetFlag :: [Char] -> Capability Bool
tiGetFlag [Char]
cap = (Terminal -> IO (Maybe Bool)) -> Capability Bool
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe Bool)) -> Capability Bool)
-> (Terminal -> IO (Maybe Bool)) -> Capability Bool
forall a b. (a -> b) -> a -> b
$ IO (Maybe Bool) -> Terminal -> IO (Maybe Bool)
forall a b. a -> b -> a
const (IO (Maybe Bool) -> Terminal -> IO (Maybe Bool))
-> IO (Maybe Bool) -> Terminal -> IO (Maybe Bool)
forall a b. (a -> b) -> a -> b
$ (CInt -> Maybe Bool) -> IO CInt -> IO (Maybe Bool)
forall a b. (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (Bool -> Maybe Bool
forall a. a -> Maybe a
Just (Bool -> Maybe Bool) -> (CInt -> Bool) -> CInt -> Maybe Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (CInt -> CInt -> Bool
forall a. Ord a => a -> a -> Bool
>CInt
0)) (IO CInt -> IO (Maybe Bool)) -> IO CInt -> IO (Maybe Bool)
forall a b. (a -> b) -> a -> b
$
                        [Char] -> (Ptr CChar -> IO CInt) -> IO CInt
forall a. [Char] -> (Ptr CChar -> IO a) -> IO a
withCString [Char]
cap Ptr CChar -> IO CInt
tigetflag
                
-- | Look up a boolean capability in the terminfo database, and fail if
-- it\'s not defined.
tiGuardFlag :: String -> Capability ()
tiGuardFlag :: [Char] -> Capability ()
tiGuardFlag [Char]
cap = [Char] -> Capability Bool
tiGetFlag [Char]
cap Capability Bool -> (Bool -> Capability ()) -> Capability ()
forall a b. Capability a -> (a -> Capability b) -> Capability b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= Bool -> Capability ()
forall (f :: * -> *). Alternative f => Bool -> f ()
guard
                
foreign import ccall tigetstr :: CString -> IO CString

{-# DEPRECATED tiGetStr "use tiGetOutput instead." #-} 
-- | Look up a string capability in the terminfo database.  NOTE: This function is deprecated; use
-- 'tiGetOutput1' instead.
tiGetStr :: String -> Capability String
tiGetStr :: [Char] -> Capability [Char]
tiGetStr [Char]
cap = (Terminal -> IO (Maybe [Char])) -> Capability [Char]
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe [Char])) -> Capability [Char])
-> (Terminal -> IO (Maybe [Char])) -> Capability [Char]
forall a b. (a -> b) -> a -> b
$ IO (Maybe [Char]) -> Terminal -> IO (Maybe [Char])
forall a b. a -> b -> a
const (IO (Maybe [Char]) -> Terminal -> IO (Maybe [Char]))
-> IO (Maybe [Char]) -> Terminal -> IO (Maybe [Char])
forall a b. (a -> b) -> a -> b
$ do
                result <- [Char] -> (Ptr CChar -> IO (Ptr CChar)) -> IO (Ptr CChar)
forall a. [Char] -> (Ptr CChar -> IO a) -> IO a
withCString [Char]
cap Ptr CChar -> IO (Ptr CChar)
tigetstr 
                if result == nullPtr || result == neg1Ptr
                    then return Nothing
                    else fmap Just (peekCString result)
    where
        -- hack; tigetstr sometimes returns (-1)
        neg1Ptr :: Ptr b
neg1Ptr = Ptr (ZonkAny 0)
forall a. Ptr a
nullPtr Ptr (ZonkAny 0) -> Int -> Ptr b
forall a b. Ptr a -> Int -> Ptr b
`plusPtr` (-Int
1)


---------------


                    
foreign import capi "term.h tparm"
    tparm :: CString -> CLong -> CLong -> CLong -> CLong -> CLong -> CLong
    -> CLong -> CLong -> CLong -- p1,...,p9
    -> IO CString

-- Note: I may want to cut out the middleman and pipe tGoto/tGetStr together
-- with tput without a String marshall in the middle.
-- directly without 

tParm :: String -> Capability ([Int] -> String)
tParm :: [Char] -> Capability ([Int] -> [Char])
tParm [Char]
cap = (Terminal -> IO (Maybe ([Int] -> [Char])))
-> Capability ([Int] -> [Char])
forall a. (Terminal -> IO (Maybe a)) -> Capability a
Capability ((Terminal -> IO (Maybe ([Int] -> [Char])))
 -> Capability ([Int] -> [Char]))
-> (Terminal -> IO (Maybe ([Int] -> [Char])))
-> Capability ([Int] -> [Char])
forall a b. (a -> b) -> a -> b
$ \Terminal
t -> Maybe ([Int] -> [Char]) -> IO (Maybe ([Int] -> [Char]))
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (Maybe ([Int] -> [Char]) -> IO (Maybe ([Int] -> [Char])))
-> Maybe ([Int] -> [Char]) -> IO (Maybe ([Int] -> [Char]))
forall a b. (a -> b) -> a -> b
$ ([Int] -> [Char]) -> Maybe ([Int] -> [Char])
forall a. a -> Maybe a
Just 
        (([Int] -> [Char]) -> Maybe ([Int] -> [Char]))
-> ([Int] -> [Char]) -> Maybe ([Int] -> [Char])
forall a b. (a -> b) -> a -> b
$ \[Int]
ps -> IO [Char] -> [Char]
forall a. IO a -> a
unsafePerformIO (IO [Char] -> [Char]) -> IO [Char] -> [Char]
forall a b. (a -> b) -> a -> b
$ Terminal -> IO [Char] -> IO [Char]
forall a. Terminal -> IO a -> IO a
withCurTerm Terminal
t (IO [Char] -> IO [Char]) -> IO [Char] -> IO [Char]
forall a b. (a -> b) -> a -> b
$
                    [CLong] -> IO [Char]
tparm' ((Int -> CLong) -> [Int] -> [CLong]
forall a b. (a -> b) -> [a] -> [b]
map Int -> CLong
forall a. Enum a => Int -> a
toEnum [Int]
ps [CLong] -> [CLong] -> [CLong]
forall a. [a] -> [a] -> [a]
++ CLong -> [CLong]
forall a. a -> [a]
repeat CLong
0)
    where tparm' :: [CLong] -> IO [Char]
tparm' (CLong
p1:CLong
p2:CLong
p3:CLong
p4:CLong
p5:CLong
p6:CLong
p7:CLong
p8:CLong
p9:[CLong]
_)
            = [Char] -> (Ptr CChar -> IO [Char]) -> IO [Char]
forall a. [Char] -> (Ptr CChar -> IO a) -> IO a
withCString [Char]
cap ((Ptr CChar -> IO [Char]) -> IO [Char])
-> (Ptr CChar -> IO [Char]) -> IO [Char]
forall a b. (a -> b) -> a -> b
$ \Ptr CChar
c_cap -> do
                result <- Ptr CChar
-> CLong
-> CLong
-> CLong
-> CLong
-> CLong
-> CLong
-> CLong
-> CLong
-> CLong
-> IO (Ptr CChar)
tparm Ptr CChar
c_cap CLong
p1 CLong
p2 CLong
p3 CLong
p4 CLong
p5 CLong
p6 CLong
p7 CLong
p8 CLong
p9
                if result == nullPtr
                    then return ""
                    else peekCString result
          tparm' [CLong]
_ = [Char] -> IO [Char]
forall a. HasCallStack => [Char] -> IO a
forall (m :: * -> *) a.
(MonadFail m, HasCallStack) =>
[Char] -> m a
fail [Char]
"tParm: List too short"

-- | Look up an output capability in the terminfo database.  
tiGetOutput :: String -> Capability ([Int] -> LinesAffected -> TermOutput)
tiGetOutput :: [Char] -> Capability ([Int] -> Int -> TermOutput)
tiGetOutput [Char]
cap = do
    str <- [Char] -> Capability [Char]
tiGetStr [Char]
cap
    f <- tParm str
    return $ \[Int]
ps Int
la -> Int -> [Char] -> TermOutput
fromStr Int
la ([Char] -> TermOutput) -> [Char] -> TermOutput
forall a b. (a -> b) -> a -> b
$ [Int] -> [Char]
f [Int]
ps

fromStr :: LinesAffected -> String -> TermOutput
fromStr :: Int -> [Char] -> TermOutput
fromStr Int
la [Char]
s = ([TermOutputType] -> [TermOutputType]) -> TermOutput
TermOutput (Int -> [Char] -> TermOutputType
TOCmd Int
la [Char]
s TermOutputType -> [TermOutputType] -> [TermOutputType]
forall a. a -> [a] -> [a]
:)

type CharOutput = CInt -> IO CInt

foreign import ccall "wrapper" mkCallback :: CharOutput -> IO (FunPtr CharOutput)

foreign import ccall tputs :: CString -> CInt -> FunPtr CharOutput -> IO ()

-- | A parameter to specify the number of lines affected.  Some capabilities
-- (e.g., @clear@ and @dch1@) use
-- this parameter on some terminals to compute variable-length padding.
type LinesAffected = Int

-- | Output a string capability.  Applies padding information to the string if
-- necessary.
tPuts :: String -> LinesAffected -> FunPtr CharOutput -> IO ()
tPuts :: [Char] -> Int -> FunPtr CharOutput -> IO ()
tPuts [Char]
s Int
n FunPtr CharOutput
putc = [Char] -> (Ptr CChar -> IO ()) -> IO ()
forall a. [Char] -> (Ptr CChar -> IO a) -> IO a
withCString [Char]
s ((Ptr CChar -> IO ()) -> IO ()) -> (Ptr CChar -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \Ptr CChar
c_str -> Ptr CChar -> CInt -> FunPtr CharOutput -> IO ()
tputs Ptr CChar
c_str (Int -> CInt
forall a. Enum a => Int -> a
toEnum Int
n) FunPtr CharOutput
putc


-- | Look up an output capability which takes a fixed number of parameters
-- (for example, @Int -> Int -> TermOutput@).
-- 
-- For capabilities which may contain variable-length
-- padding, use 'tiGetOutput' instead.
tiGetOutput1 :: forall f . OutputCap f => String -> Capability f
tiGetOutput1 :: forall f. OutputCap f => [Char] -> Capability f
tiGetOutput1 [Char]
str = do
    cap <- [Char] -> Capability [Char]
tiGetStr [Char]
str
    guard (hasOkPadding (undefined :: f) cap)
    f <- tParm cap
    return $ outputCap f []


-- OK, this is the structure that I want:
class OutputCap f where
    hasOkPadding :: f -> String -> Bool
    outputCap :: ([Int] -> String) -> [Int] -> f

instance OutputCap [Char] where
    hasOkPadding :: [Char] -> [Char] -> Bool
hasOkPadding [Char]
_ = Bool -> Bool
not (Bool -> Bool) -> ([Char] -> Bool) -> [Char] -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [Char] -> Bool
strHasPadding 
    outputCap :: ([Int] -> [Char]) -> [Int] -> [Char]
outputCap [Int] -> [Char]
f [Int]
xs = [Int] -> [Char]
f ([Int] -> [Int]
forall a. [a] -> [a]
reverse [Int]
xs)

instance OutputCap TermOutput where
    hasOkPadding :: TermOutput -> [Char] -> Bool
hasOkPadding TermOutput
_ = Bool -> [Char] -> Bool
forall a b. a -> b -> a
const Bool
True
    outputCap :: ([Int] -> [Char]) -> [Int] -> TermOutput
outputCap [Int] -> [Char]
f [Int]
xs = Int -> [Char] -> TermOutput
fromStr Int
1 ([Char] -> TermOutput) -> [Char] -> TermOutput
forall a b. (a -> b) -> a -> b
$ [Int] -> [Char]
f ([Int] -> [Char]) -> [Int] -> [Char]
forall a b. (a -> b) -> a -> b
$ [Int] -> [Int]
forall a. [a] -> [a]
reverse [Int]
xs

instance (Enum p, OutputCap f) => OutputCap (p -> f) where
    outputCap :: ([Int] -> [Char]) -> [Int] -> p -> f
outputCap [Int] -> [Char]
f [Int]
xs = \p
x -> ([Int] -> [Char]) -> [Int] -> f
forall f. OutputCap f => ([Int] -> [Char]) -> [Int] -> f
outputCap [Int] -> [Char]
f (p -> Int
forall a. Enum a => a -> Int
fromEnum p
xInt -> [Int] -> [Int]
forall a. a -> [a] -> [a]
:[Int]
xs)
    hasOkPadding :: (p -> f) -> [Char] -> Bool
hasOkPadding p -> f
_ = f -> [Char] -> Bool
forall f. OutputCap f => f -> [Char] -> Bool
hasOkPadding (f
forall a. HasCallStack => a
undefined :: f)


{- $outputdoc
Terminfo contains many string capabilities for special effects.
For example, the @cuu1@ capability moves the cursor up one line; on ANSI terminals
this is accomplished by printing the control sequence @\"\\ESC[A\"@.
However, some older terminals also require \"padding\", or short pauses, after certain commands.
For example, when @TERM=vt100@ the @cuu1@ capability is @\"\\ESC[A$\<2\>\"@, which instructs terminfo
to pause for two milliseconds after outputting the control sequence.

The 'TermOutput' monoid abstracts away all padding and control
sequence output.  Unfortunately, that datatype is difficult to integrate into existing 'String'-based APIs
such as pretty-printers.  Thus, as a workaround, 'tiGetOutput1' also lets us access the control sequences as 'String's.  The one caveat is that it will not allow you to access padded control sequences as Strings.  For example:

   > > t <- setupTerm "vt100"
   > > isJust (getCapability t (tiGetOutput1 "cuu1") :: Maybe String)
   > False
   > > isJust (getCapability t (tiGetOutput1 "cuu1") :: Maybe TermOutput)
   > True

'String' capabilities will work with software-based terminal types such as @xterm@ and @linux@.
However, you should use 'TermOutput' if compatibility with older terminals is important.
Additionally, the @visualBell@ capability which flashes the screen usually produces its effect with a padding directive, so it will only work with 'TermOutput'.

-}


class (Monoid s, OutputCap s) => TermStr s

instance TermStr [Char]
instance TermStr TermOutput