def get_violations(spec: Union[str, Iterable[str]]):
"""Get the list of violations for a given specification. Returns None if the
problem is not satisfiable.
Internally, Draco checks against the definitions, constraints, helpers,
and hard constraints.
:param spec: The specification top check
"""
if not isinstance(spec, str):
spec = "\n".join(spec)
c = "".join(
blocks_to_program(
constraints.blocks, set(constraints.blocks.keys()) - set(["violation"])
)
)
program = definitions.program + c + helpers.program + hard.program + spec
try:
model = next(run_clingo(program, 1))
return [
symbol.arguments[0].name
for symbol in model.answer_set
if symbol.name == "violation"
]
except StopIteration:
# Since the problem is not satisfiable, we return None to distinguish it from
# satisfiable programs where you would expect violations to be []
return None
def is_valid(draco_query: List[str], debug=False) -> bool:
""" Check a task.
Args:
draco_query: a list of facts
Returns:
whether the task is valid
"""
_, stdout = run_clingo(draco_query,
files=["define.lp", "hard.lp"],
silence_warnings=True,
debug=debug)
return json.loads(stdout)["Result"] != "UNSATISFIABLE"
def test_dict_to_fact_and_answer_set_to_dict():
expected = {
"view": [
{
"mark": [
{"type": "bar", "encoding": [{"channel": "x", "field": "foo"}]}
],
"scale": [{"channel": "x", "type": "linear"}],
}
],
}
program = dict_to_facts(expected)
result = run_clingo(program)
assert answer_set_to_dict(next(result).answer_set) == expected
def test_answer_set_to_dict():
program = [
# root
"attribute(numberRows,root,42).",
# first field
"entity(field,root,0).",
"attribute((field,unique),0,12).",
"attribute((field,type),0,number).",
# second fields
"entity(field,root,1).",
"attribute((field,unique),1,32).",
"attribute((field,type),1,string).",
]
result = run_clingo(program)
assert answer_set_to_dict(next(result).answer_set) == {
"numberRows": 42,
"field": [
{"unique": 12, "type": "number"},
{"unique": 32, "type": "string"},
],
}