Overview Description The Haskell 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. Prerequisites * A UNIX or UNIX-like operating system, e.g., NetBSD, Solaris, Mac OS X, or Linux. The Haskell 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. Installation * Unzip this archive under the 'backends' directory of your ECSpooler installation (for example '/opt/ESpooler/backends/'). * 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 When executing unknown code, you have to take security precautions, e.g., by using chroot, jails, or systrace. These mechanisms are, however, system-dependent, so we cannot give detailed installation instructions. If you are using "systrace":http://www.systrace.org/, adjust the script 'backends/haskell/runhugs+systrace' to your system environment and set *interpreter* in 'backends/haskell/HaskellConf.py' to this script. Please 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 Haskell backend using the following command (you may have to specify the path):: backendctl -u root -p bazquux Haskell 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 and get a response similar to:: {'queue': 0, 'backends': ['haskell'], 'pid': 26425, '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 Haskell backend requires a model solution and a set of test data, e.g., * Model solution:: square x = x * x * Test data (one test call per line):: square 0 square 2 square 3 The Haskell 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 More Haskell testing Testing I/O code in Haskell ist supported by the *HaskellIO* backend. The *HaskellQC* backend uses "QuickCheck":http://www.cs.chalmers.se/~rjmh/QuickCheck/ for testing with properties and random test data. Support For questions and discussions about backends, please join the "eduComponents mailing list":https://listserv.uni-magdeburg.de/mailman/listinfo/educomponents. Credits The Haskell backend was written by "Mario Amelung":mailto:mario.amelung@gmx.de. License The Haskell backend is licensed under the "GPL":http://opensource.org/licenses/gpl-license. Copyright © 2007-2011 Otto-von-Guericke-Universität Magdeburg The Haskell 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 Haskell 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