Use of Cabal

Cabal is an utility program that facilitates the creation of Haskell projects and the development of large Haskell programs.

Relevant Reference Manuals

• Cabal (Version 3.6 of the reference manual)

Installation and First Use

When you install the entire Haskell platform with the command

sudo apt-get install haskell-platform

Cabal is installed together with the Haskell compiler some tools and the most important libraries.

If you did not install the entire Haskell platform, you can install Cabal separately with the command:

sudo apt-get install cabal-install

First start:

To download the package list you should update Cabal. You do it this way:

boris@boris-jetson:~/$ cabal update
Downloading the latest package list from hackage.haskell.org

The download may take some time.

boris@boris-jetson:~/$ cabal --version
cabal-install version 1.24.0.2
compiled using version 1.24.2.0 of the Cabal library 

Set up a project

to create a simple project, it is sufficient to execute this command:

cabal init  --non-interactive --is-executable --source-dir=src --license=GPL --main-is=Main.hs --package-name=CabalProject

mkdir CabalProject
cd CabalProject
cabal init

You are now asked some questions about your new project:

boris@boris-jetson:~/CabalProject$ cabal init
Warning: The package list for 'hackage.haskell.org' does not exist. Run 'cabal
update' to download it.
Package name? [default: Example003-cabal] 
Package version? [default: 0.1.0.0] 
Please choose a license:
   1) GPL-2
   2) GPL-3
   3) LGPL-2.1
   4) LGPL-3
   5) AGPL-3
   6) BSD2
 * 7) BSD3
   8) MIT
   9) ISC
  10) MPL-2.0
  11) Apache-2.0
  12) PublicDomain
  13) AllRightsReserved
  14) Other (specify)
Your choice? [default: BSD3] 1
Author name? Boris Gaertner
Maintainer email? Boris.Gaertner@gmx.net
Project homepage URL? 
Project synopsis? A simple test project
Project category:
 * 1) (none)
   2) Codec
   3) Concurrency
   4) Control
   5) Data
   6) Database
   7) Development
   8) Distribution
   9) Game
  10) Graphics
  11) Language
  12) Math
  13) Network
  14) Sound
  15) System
  16) Testing
  17) Text
  18) Web
  19) Other (specify)
Your choice? [default: (none)] 10              
What does the package build:
   1) Library
   2) Executable
Your choice? 2
What is the main module of the executable:
 * 1) Main.hs (does not yet exist, but will be created)
   2) Main.lhs (does not yet exist, but will be created)
   3) Other (specify)
Your choice? [default: Main.hs (does not yet exist, but will be created)] 
Source directory:
 * 1) (none)
   2) src
   3) Other (specify)
Your choice? [default: (none)] 2
What base language is the package written in:
 * 1) Haskell2010
   2) Haskell98
   3) Other (specify)
Your choice? [default: Haskell2010] 
Add informative comments to each field in the cabal file (y/n)? [default: n] y

Guessing dependencies...

Generating LICENSE...
Generating Setup.hs...
Generating ChangeLog.md...
Generating src/Main.hs...
Generating Example003-cabal.cabal...

You may want to edit the .cabal file and add a Description field.

It is possible to add some parameters to create a new project with a more complicated call of cabal

cabal init --help

You can immediately compile and run you programm:

cabal run :CabalProject

life cycle:

configure
build
run
clean 

ghc: setNumCapabilities: not supported on this platform
sudo apt-get install libghc-base-compat-dev

Das hilft nicht; die Meldung kommt noch immer.