This document introduces virthualenvwrapper, a tool for Haskell that allows creating and managing isolated virtual environments for Haskell projects similarly to virtualenvwrapper for Python. It describes how to install virthualenvwrapper from GitHub, create a new virtual environment called "testenv", switch between environments, and list all existing environments. The goal is to provide a convenient way to manage multiple Haskell toolchains and package configurations.

1. Virthualenvwrapper
三島Haskell無名関数の会#2
@kzfm

2. へびちゅうにゅう∼
h"p://www.flickr.com/photos/56879816@N00/187827715

3. Virthualenvは
Pythonのvirtualenv
インスパイア
(知ってるよね？)

4. Pythonには
virtualenvwrapperがあるよ！
(virtualenvを快適に使える)

5. 快適すぎるので
Haskellでもつくった
(virthualenvwrapper)

6. install from Github
$ git://github.com/kzfm/virthualenvwrapper.git
$ cd virthualenvwrapper
$ cabal install
# add to .bashrc
$ echo “source $HOME/Library/Haskell/ghc-7.4.2/lib/
virthualenvwrapper-0.1.0.0/share/virthualenvwrapper.sh”
>> ~/.bashrc
$ source ~/.bashrc

7. make new env
$ mkvhenv testenv
Use regular Haskell tools (ghc, ghci, ghc-pkg, cabal)
to manage your Haskell environment.
To exit from this virtual environment, enter command 'deactivate'.
(testenv)localhost@kzfm:~ $

8. switch env
$ deactivate
Deactivating testenv Virtual Haskell Environment
(at /Users/kzfm/.virthualenv/testenv).
Restoring previous environment settings.
localhost@kzfm:~ $ workhon yesod
Activating yesod Virtual Haskell Environment
(at /Users/kzfm/.virthualenv/yesod).
Use regular Haskell tools (ghc, ghci, ghc-pkg, cabal)
to manage your Haskell environment.
To exit from this virtual environment, enter command 'deactivate'.
(yesod)localhost@kzfm:~ $

9. list all env
$ lsvirthualenv
curl
optparse
snap
testenv
yesod

10. おしまい