ASPars

Quick and easy parsing of Answer Sets into friendly python structures.

Specification

ASPars allows the user to parse answer sets represented in the following formats:

• wasp format, e.g., {a, b(x), c(y,...,z), ...},
• clasp format, e.g., a b(x) c(y,...,z) ....

An answer set is parsed into a list of predicates. A predicate is represented as a dictionary with the following keys:

• name: name of the predicate,
• ext: a list of the (heterogeneous) values of the predicate,
• arity: arity of the predicate (e.g., length of the extension).

If the predicate is an atom, then only name is defined.

Example

{a, foo(x), bar(42,"42")} is parsed into the following singleton:

[
    {'name': 'a'},
    {'name': 'foo', 'ext': ['x'], 'arity': 1},
    {'name': 'bar', 'ext': [42, '"42"'], 'arity': 2}
]

Usage

ASPars can be used by simply importing it or as a standalone module.

Importing ASPars in a python program

from aspars import ASPars

answer_sets_waspf = [
    '{a, foo(x), bar(-1,1), fizz("42")}',
    '{b, foo(y), bar(-2,2)}',
    '{c, foo(z), fizz("24")}',
]

# parses only the first answer set, returns a singleton
single = ASPars(syntax='wasp').parse(answer_sets_waspf[0])
# parse all the answer sets, returns an iterable (map)
multi = ASPars(syntax='wasp').parse(answer_sets_waspf)

# example in clasp syntax
single = ASPars(syntax='clasp').parse('b foo(y) bar(-2,2)')

Using ASPars as a standalone module

$ cat my_answer_sets | python -m aspars