VALASP

Validation for Answer Set Programming by specification rules written in YAML or Python. Details on the usage are given in the online documentation: https://alviano.github.io/valasp. A taste is given in the usage section.

Setup

Obtain a local copy of the repository:

$ git clone git@github.com:alviano/valasp.git
$ cd valasp

Execute the following script to create a conda environment with all dependencies:

$ ./bin/create-environment.sh

Don't forget to activate the environment with

$ conda activate valasp

where valasp is the name given to the virtual environment.

To install valasp as a pip module, use the following command:

$ pip install -e .

To run all tests, use the following command:

$ pytest

Usage

Activate the environment with

$ conda activate valasp

where valasp is the name given to the virtual environment. Let's try to validate examples/bday.invalid.asp against the specification given in examples/bday.yaml:

(valasp) $ python -m valasp examples/bday.yaml examples/bday.invalid.asp 
VALIDATION FAILED
=================
Invalid instance of bday:
    in constructor of bday
    in constructor of date
  with error: expecting arity 3 for TUPLE, but found 2; invalid term (1982,123) in atom bday(bigel,(1982,123))
=================

We are pointed to an invalid term in an invalid atom. If valasp is used at coding time, it is likely that this minimal information will drive you to quickly identify the origin of the problem. The content of the two files is the following:

(valasp) $ cat examples/bday.yaml
valasp:
    python: |+
        import datetime

date:
    year: Integer
    month: Integer
    day: Integer    

    valasp:
        validate_predicate: False
        with_fun: TUPLE
        after_init: |+
            datetime.datetime(self.year, self.month, self.day)

bday:
    name: Alpha
    date: date
    
(valasp) $ cat examples/bday.invalid.asp 
bday(sofia, (2019,6,25)).
bday(leonardo, (2018,2,1)).
bday(bigel, (1982,123)).

Documentation

The documentation is available online at https://alviano.github.io/valasp.

The documentation is produced with sphinx, which can be added to the virtual environment with the following command:

$ conda install sphinx

To produce a local copy of the documentation, run the following commands:

$ cd docs
$ make generate
$ make html

The HTML documentation can then be found in docs/builds/html/index.html.

Copyright

Copyright 2020 Mario Alviano and Carmine Dodaro

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.