Overview

Description

The HaskellExt backend is a Python XML-RPC service, which provides -

in tandem with ECSpooler - automatic testing of Haskell programs.

Therefore the backend compares the output of a program with the

output of a model solution for a set of test data.

The HaskellExt backend is derived from the Haskell backend and

should be used if a test data call doesn't start with the function

which should be tested (see the example below).

Prerequisites

* A UNIX or UNIX-like operating system, e.g., NetBSD, Solaris, Mac

OS X, or Linux.

The HaskellExt backend does run on Windows (with some

restrictions), but this is neither supported nor recommended.

* "Python":http://python.org/

* "Hugs":http://www.haskell.org/hugs/

* "ECSpooler":http://wdok.cs.uni-magdeburg.de/software/ecspooler

* ECSpooler is primarily intended to be used via the

"ECAutoAssessmentBox":http://plone.org/products/ecautoassessmentbox

Plone product. So you will normally have a Plone installation

with ECAutoAssessmentBox.

* Haskell backend since HaskellExt is derived from it.

Installation

* Unzip this archive under the 'backends' directory of your

ECSpooler installation (for example '/opt/ESpooler/backends/').

* Even if the Haskell backend is already installed, please

check the following twice

* Adjust values for INTERPRTER and OPTIONS in the script

'backends/haskell/runhugs.sh' to your system environemnt.

* Make sure that the script 'backends/haskell/runhugs.sh' is

executable.

Security

Please read the security section in the Haskell backend's README

file and be be aware of the risks if you are *not* able to deal with

the configuration issues.

Quick Start

After installation, first start ECSpooler (see the ECSpooler

documentation for details). Then you should be able to start the

HaskellExt backend using the following command (you may have to

specify the path)::

backendctl -u root -p bazquux HaskellExt start

If you run this command as root, the process will be started as user

"nobody".

Once the backend is running, check the status of the backend using::

spoolerctl -u root -p bazquux status

or

backendctl -u root -p bazquux HaskellExt status

and get a response similar to::

{'queue': 0, 'backends': ['haskellext'], 'pid': 2642, 'results': 0}

For administrative tasks such as starting/stopping backends

authentication is required. Therefore ECSpooler ships with a

password file ('etc/passwd') containing a user "root" with default

password "bazquux". See the ECSpooler documentation if you would

like to add/change users and passwords.

Testing a Haskell program with the HaskellExt backend requires a

model solution and a set of test data, e.g.,

TODO:

* Model solution::

infiniteOddNumbers :: Int -> [Int]

infiniteOddNumbers startFrom = [ x | x <- [startFrom ..], odd x]

* Test data (one test call per line)::

take 10 (infiniteOddNumbers 0)

take 10 (infiniteOddNumbers 3)

take 10 (infiniteOddNumbers (-5))

The HaskellExt backend currently supports three compare modes:

* simple - the results of the student and model solutions for same

test data must be equal

* permutation - accept student solution if the returned list is a

permutation of the result from the model solution

* tolerance - result of student and model solution must be equal to

15 positions after decimal point

For questions and discussions about backends, please join the

"eduComponents mailing

list":https://listserv.uni-magdeburg.de/mailman/listinfo/educomponents.

The HaskellExt backend was written by "Mario

Amelung":http://wdok.cs.uni-magdeburg.de/Members/amelung.

The HaskellExt backend is licensed under the

"GPL":http://opensource.org/licenses/gpl-license.

Copyright © 2007-2011 Otto-von-Guericke-Universität Magdeburg

The HaskellExt backend is free software; you can redistribute it

and/or modify it under the terms of the GNU General Public License as

published by the Free Software Foundation; either version 2 of the

License, or (at your option) any later version.

The HaskellExt backend is distributed in the hope that it will be

useful, but WITHOUT ANY WARRANTY; without even the implied warranty

of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with ECSpooler; if not, write to the Free Software Foundation,

Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA