| Portability | portable (FFI) |
|---|---|
| Stability | experimental |
| Maintainer | judah.jacobson@gmail.com |
| Safe Haskell | Trustworthy |
System.Console.Terminfo.Base
Description
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.
- data Terminal
- setupTerm :: String -> IO Terminal
- setupTermFromEnv :: IO Terminal
- data SetupTermError
- data Capability a
- getCapability :: Terminal -> Capability a -> Maybe a
- tiGetFlag :: String -> Capability Bool
- tiGuardFlag :: String -> Capability ()
- tiGetNum :: String -> Capability Int
- tiGetStr :: String -> Capability String
- tiGetOutput1 :: forall f. OutputCap f => String -> Capability f
- class OutputCap f
- class (Monoid s, OutputCap s) => TermStr s
- data TermOutput
- runTermOutput :: Terminal -> TermOutput -> IO ()
- hRunTermOutput :: Handle -> Terminal -> TermOutput -> IO ()
- termText :: String -> TermOutput
- tiGetOutput :: String -> Capability ([Int] -> LinesAffected -> TermOutput)
- type LinesAffected = Int
- class Monoid a where
- (<#>) :: Monoid m => m -> m -> m
Initialization
data Terminal
setupTerm :: String -> IO Terminal
Initialize the terminfo library to the given terminal entry.
Throws a SetupTermError if the terminfo database could not be read.
setupTermFromEnv :: IO Terminal
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.
data SetupTermError
Instances
| Show SetupTermError | |
| Typeable SetupTermError | |
| Exception SetupTermError |
Capabilities
data Capability a
A feature or operation which a Terminal may define.
Instances
| Monad Capability | |
| Functor Capability | |
| MonadPlus Capability |
getCapability :: Terminal -> Capability a -> Maybe a
tiGetFlag :: String -> Capability Bool
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.
tiGuardFlag :: String -> Capability ()
Look up a boolean capability in the terminfo database, and fail if it's not defined.
tiGetNum :: String -> Capability Int
Look up a numeric capability in the terminfo database.
tiGetStr :: String -> Capability String
Deprecated: use tiGetOutput instead.
Look up a string capability in the terminfo database. NOTE: This function is deprecated; use
tiGetOutput1 instead.
Output
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 Strings. 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.
tiGetOutput1 :: forall f. OutputCap f => String -> Capability f
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.
class OutputCap f
Instances
| OutputCap TermOutput | |
| OutputCap [Char] | |
| (Enum p, OutputCap f) => OutputCap (p -> f) |
TermOutput
data TermOutput
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.
Instances
runTermOutput :: Terminal -> TermOutput -> IO ()
Write the terminal output to the standard output device.
hRunTermOutput :: Handle -> Terminal -> TermOutput -> IO ()
Write the terminal output to the terminal or file managed by the given
Handle.
termText :: String -> TermOutput
tiGetOutput :: String -> Capability ([Int] -> LinesAffected -> TermOutput)
Look up an output capability in the terminfo database.
type LinesAffected = Int
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.
Monoid functions
class Monoid a where
Instances
| Monoid Ordering | |
| Monoid () | |
| Monoid Any | |
| Monoid All | |
| Monoid TermOutput | |
| Monoid [a] | |
| Monoid a => Monoid (Maybe a) | |
| Num a => Monoid (Sum a) | |
| Num a => Monoid (Product a) | |
| Monoid (Last a) | |
| Monoid (First a) | |
| Monoid (Endo a) | |
| Monoid a => Monoid (Dual a) | |
| Monoid b => Monoid (a -> b) | |
| (Monoid a, Monoid b) => Monoid (a, b) | |
| (Monoid a, Monoid b, Monoid c) => Monoid (a, b, c) | |
| (Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d) | |
| (Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e) |