Yi is a text editor written in Haskell and extensible in Haskell. The goal of Yi is to provide a flexible, powerful and correct editor core scriptable in Haskell.
Its features include
- a purely functional editor core;
- keybindings written as parsers of the input;
- Emacs, Vim and Cua (subset) emulations provided by default;
- Vty (terminal) and Gtk-based Pango UIs
The long term goal of the project is to make Yi the editor of choice for the haskell hacker. The main short term goal is to maximize Yi's Fun Factor. This means that we want to
- improve hackability (and therefore architecture) and
- add cool features.
We also want to simplify the core Yi package to make it more accessible, splitting some parts into several packages.
Other information (much of it old) is available on the Haskell wiki.
- Installing
- Getting Source
- Reporting Bugs
- Mailing List
- IRC channel
- Configuring Yi
- Frontend Compatibility
- Profiling
- Reading material
Yi requires the Haskell Platform 2011.2.0.0 at minimum (for GHC 7, alex, and cabal-install, among other things).
With the Haskell Platform installed, yi should be installed with cabal-install:
$ cabal update
$ cabal install yi
On Linux systems, you'll probably need ncurses development headers for the Vty frontend. On Ubuntu, you'll need to install the libncurses5-dev package.
You can specify frontends to compile, also:
$ cabal install yi -fvty -fpango
Options are -fvty and -fpango.
You can also install the yi-contrib package, which contains some extra contributed things (like user configs):
$ cabal install yi-contrib
If you're in the source repository, you can install yi from source:
$ cabal update # Still update to get updated dependencies
$ (cd yi && cabal install)
And the contrib package:
$ (cd yi-contrib && cabal install)
If you're getting errors about Alex version bounds or are experiencing similar problems, it's recommended that you install from the sources available in the GitHub repository which has the version bounds adjusted and contains a couple of nice fixes that might not be present in the latest Hackage version.
Many people want to install Yi inside a cabal sandbox (cabal-install 1.18 feature). This is especially important if you plan on hacking on Yi itself or on libraries for Yi.
As Yi compiles your config file once you start it, the config needs to know where to look for any of its dependencies, such as Yi itself! If these are inside of the sandbox, it doesn't know where to look and you'll get config compilation errors due to missing modules.
To sandbox, navigate to your source yi directory. For me it's
~/programming/yi/yi.
We then setup a cabal sandbox following instructions from the cabal userguide:
$ cabal sandbox init
$ cabal install --only-dependencies
$ cabal build
From cabal-install 1.20, Yi can be launched in an environment using the
sandbox's package DB using cabal exec ./dist/build/yi/yi. It may be useful
to create an alias or small script for this, along the lines of:
#!/bin/bash
YI_DIR=$HOME/programming/yi/yi
env CABAL_SANDBOX_CONFIG=$YI_DIR/cabal.sandbox.config cabal exec $YI_DIR/dist/build/yi/yi "$@"
The "$@" part means that all the
arguments we pass to this script are passed on to the Yi binary which
means we can still use all the regular flags, such as runyi --as=emacs. Of course, you'll need to adjust the paths used to match
your sandbox and package directories.
There's one more thing to mention in this section and that is config dependencies. One of the great things about Yi is that we have access to the wealth of existing Haskell libraries and we can take advantage of this in our config file. There are two scenarios:
If the package your config depends on is on Hackage and you want to
use that, just use cabal install in the sandboxed Yi directory. So
if your config depends on semigroups, you'd run cabal install semigroups. After doing this, semigroups should now be visible when
your config is getting compiled.
If the package your config depends on is local, for example when
you're developing the library that you want to use or if you need a
patched version, you'll have to use cabal sandbox add-source
command. As an example, I'm developing a yi-haskell-utils package
and my config depends on it. To accommodate for this, I ran cabal sandbox add-source ~/programming/yi-haskell-utils.
You can then cabal install yi-haskell-utils to add the package to
the sandbox. You should call cabal build in the sandbox directory
after you modify a local package so that the sandbox has an up-to-date
version of the package.
I suspect that it'd be perfectly possible to make your config file into a cabal project and manage the dependencies that way but I have not yet investigated this approach.
Yi source repository is available on GitHub.
To get the git version,
$ git clone git://github.com/yi-editor/yi.git
(There may be more repositories in the future, as yi is split more.)
Please report issues on GitHub.
Our mailing list is yi-devel, hosted at Google Groups. Please ask us questions on this list! All development discussion occurs on this list.
Our channel is #yi at Freenode. Please note that it is rather slow (very slow compared to #haskell), so be prepared to stay for longer than 5 minutes.
Yi uses the Dyre package to have dynamic reconfiguration. You can configure Yi by creating ~/.config/yi/yi.hs, and then Yi is reconfigured whenever you update this file. Example configuration files are in yi/examples/ (copy any of these into ~/.config/yi/ as yi.hs and restart Yi).
You can also use the sample user configs in the yi-contrib package (see the list of user configs in the source repository on GitHub). To use one of these configurations, install the package and then create a configuration file ~/.config/yi/yi.hs like this:
import Yi
import Yi.Config.Users.Anders
main = yi config
It's possible to customize even these user configs in the same way as the example configurations.
| Vty Pango
--------+----------------
Linux | X X
OSX | X X
Windows | X
Windows support for Vty may eventually come; patches on the vty package would certainly be appreciated.
The plan is to move the UI frontends into separate packages, but this has not yet happened.
If you're interested in optimizing Yi, here is a way to get profiling:
- Change ghcOptions in
yi/src/library/Yi/Main.hs:
- ghcOptions = [],
+ ghcOptions = ["-auto-all", "-prof", "-osuf=p_o", "-hisuf=p_hi", "-rtsopts"],
- Recompile yi with
--enable-library-profiling:
cabal configure --enable-library-profiling && cabal install --reinstall
-
Run
yifirst to get a compiled real executable. -
Then call real executable from cache directory with profiling options. On any XDG-compatible (Unix-like) system this should look like:
~/.cache/yi/yi-linux-x86_64 +RTS -Pa
There are some papers which might interest you. If you plan on hacking on Yi, it's very recommended that you read these
-
Robust & Precise incremental parsing of Haskell talks about the precise Haskell mode.