You need recent versions of the following programs:
- GHC: https://www.haskell.org/ghc/
- cabal-install: https://www.haskell.org/cabal/
- Alex: https://www.haskell.org/alex/
- Happy: https://www.haskell.org/happy/
- GNU Emacs: http://www.gnu.org/software/emacs/
You should also make sure that programs installed by cabal-install are on your shell’s search path.
For instructions on installing a suitable version of Emacs under Windows, see Installing Emacs under Windows.
Non-Windows users need to ensure that the development files for the C libraries zlib* and ncurses* are installed (see http://zlib.net and http://www.gnu.org/software/ncurses/). Your package manager may be able to install these files for you. For instance, on Debian or Ubuntu it should suffice to run
apt-get install zlib1g-dev libncurses5-dev
as root to get the correct files installed.
Optionally one can also install the ICU library, which is used to implement
--count-clusters flag. Under Debian or Ubuntu it may suffice
to install libicu-dev. Once the ICU library is installed one can
hopefully enable the
--count-clusters flag by giving the
-fenable-cluster-counting flag to cabal install.