vty is a terminal interface library. It provides a high-level
interface for doing terminal I/O. Vty is supported on GHC versions
7.10.1 and up.
git clone git://github.com/jtdaugherty/vty.git
cabal install vty
Supports a large number of terminals. vt100, ansi, hurd, linux, screen, etc., or anything with a sufficient terminfo entry.
Automatic handling of window resizes.
Unicode output on terminals with UTF-8 support.
Handles multi-column glyphs. (Requires user to properly configure terminal.)
Efficient output. Output buffering and terminal state changes are minimized.
Minimizes repaint area, which virtually eliminates the flicker problems that plague ncurses programs.
A pure, compositional interface for efficiently constructing display images.
Automatically decodes keyboard keys into (key,[modifier]) tuples.
Automatically supports refresh on Ctrl-L.
Supports a keypress timeout after for lone ESC. The timeout is customizable.
The interface is designed for easy extension.
Supports ANSI graphics modes (SGR as defined in
console_codes(4)) with a type-safe interface and graceful fallback for terminals with limited or nonexistent support for such modes.
Properly handles cleanup (but not due to signals).
Provides a comprehensive test suite.
Supports "normal" and "extended" (SGR) mouse modes as described at http://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-Mouse-Tracking
Supports bracketed paste mode as described at http://cirw.in/blog/bracketed-paste
Vty uses threads internally, so programs made with Vty need to be
compiled with the threaded runtime using the GHC
Uses terminfo to determine terminal protocol. With some special rules to handle some omissions from terminfo.
Unsupported (but contributions and testing here are very welcome!)
If you decide to contribute, that's great! Here are some guidelines you should consider to make submitting patches easier for all concerned:
- If you want to take on big things, talk to me first; let's have a design/vision discussion before you start coding. Create a GitHub issue and we can use that as the place to hash things out.
- If you make changes, make them consistent with the syntactic conventions already used in the codebase.
- Please provide Haddock documentation for any changes you make.
ncurses to the user environment:
LIBRARY_PATH=$HOME/.nix-profile/lib/ cabal configure --enable-tests --extra-lib-dirs=$HOME/.nix-profile/lib LIBRARY_PATH=$HOME/.nix-profile/lib/ cabal build LIBRARY_PATH=$HOME/.nix-profile/lib/ cabal test
As of last testing, profiling causes issues with coverage when enabled. To evaluate coverage, configure as follows:
rm -rf dist ; cabal configure --enable-tests --enable-library-coverage \ --disable-library-profiling \ --disable-executable-profiling
rm -rf dist ; cabal configure --enable-tests --disable-library-coverage \ --enable-library-profiling \ --enable-executable-profiling
Terminals have numerous quirks and bugs. Vty picks what works best for the author in ambiguous or buggy situations.
Signal handling of STOP, TERM and INT are nonexistent.
The character encoding of the terminal is assumed to be UTF-8 if unicode is used.
Terminfo is assumed to be correct unless there is an override configured. Some terminals will not have correct special key support (shifted F10 etc). See
Configfor customizing vty's behavior for a particular terminal.
TIOCGWINSZioctl to find the current window size, which appears to be limited to Linux and BSD.
Good sources of documentation for terminal programming are: