def visit_literal(self, node: Node, children: List) -> 'Literal':
from foil.models import Literal
try:
return Literal(children[1], children[0])
except IndexError:
return Literal(children[0], False)
def find_literal(
hypotheses: List['Clause'],
target: 'Literal',
body: List['Literal'],
background: List['Clause'],
masks: List['Literal'],
constants: List['Value'],
positives: List['Assignment'],
negatives: List['Assignment'],
) -> Optional[Candidate]:
from foil.models import Atom
from foil.models import Clause
from foil.models import Literal
from foil.models import Program
candidate, table, bound = None, get_table([target, *body]), max_gain(
positives, negatives)
for mask in masks:
for items in itemize(table, mask.arity):
literal = Literal(Atom(mask.functor, items), mask.negated)
world = Program(
[*hypotheses,
Clause(target, [*body, literal]), *background]).ground()
positives_i = extend(positives, literal, constants, world)
negatives_i = extend(negatives, literal, constants, world)
score = gain(positives, negatives, positives_i, negatives_i)
if candidate and bound < candidate.score:
break
if candidate is None or score > candidate.score:
candidate = Candidate(score, literal, positives_i, negatives_i)
return candidate
def test__get_arity(self):
for i, entry in enumerate([
(Literal.parse('func'), 0),
(Literal.parse('func()'), 0),
(Literal.parse('func(term)'), 1),
(Literal.parse('func(term, 5.0)'), 2),
(Literal.parse('func(term, 5.0, True)'), 3),
(Literal.parse('~func'), 0),
(Literal.parse('~func()'), 0),
(Literal.parse('~func(term)'), 1),
(Literal.parse('~func(term, 5.0)'), 2),
(Literal.parse('~func(term, 5.0, True)'), 3),
]):
atom, expected = entry
with self.subTest(i=i, value=entry):
result = atom.get_arity()
assert_that(result, 'Literal.get_arity(self) -> int:') \
.is_equal_to(expected)
def test__substitute(self):
for i, entry in enumerate([
(Literal.parse('pred.'), {}, Literal.parse('pred.')),
(Literal.parse('pred.'), {'X': 'a'}, Literal.parse('pred.')),
(Literal.parse('pred.'), {'Y': 'X'}, Literal.parse('pred.')),
(Literal.parse('pred(a).'), {}, Literal.parse('pred(a).')),
(Literal.parse('pred(a).'), {'X': 'a'}, Literal.parse('pred(a).')),
(Literal.parse('pred(a).'), {'Y': 'X'}, Literal.parse('pred(a).')),
(Literal.parse('pred(X).'), {}, Literal.parse('pred(X).')),
(Literal.parse('pred(X).'), {'X': 'a'}, Literal.parse('pred(a).')),
(Literal.parse('pred(X).'), {'Y': 'X'}, Literal.parse('pred(X).')),
(Literal.parse('pred(Y).'), {}, Literal.parse('pred(Y).')),
(Literal.parse('pred(Y).'), {'X': 'a'}, Literal.parse('pred(Y).')),
(Literal.parse('pred(Y).'), {'Y': 'X'}, Literal.parse('pred(X).')),
(Literal.parse('pred(X, Y).'), {}, Literal.parse('pred(X, Y).')),
(Literal.parse('pred(X, Y).'), {'X': 'a'}, Literal.parse('pred(a, Y).')),
(Literal.parse('pred(X, Y).'), {'Y': 'X'}, Literal.parse('pred(X, X).')),
(Literal.parse('~pred.'), {}, Literal.parse('~pred.')),
(Literal.parse('~pred.'), {'X': 'a'}, Literal.parse('~pred.')),
(Literal.parse('~pred.'), {'Y': 'X'}, Literal.parse('~pred.')),
(Literal.parse('~pred(a).'), {}, Literal.parse('~pred(a).')),
(Literal.parse('~pred(a).'), {'X': 'a'}, Literal.parse('~pred(a).')),
(Literal.parse('~pred(a).'), {'Y': 'X'}, Literal.parse('~pred(a).')),
(Literal.parse('~pred(X).'), {}, Literal.parse('~pred(X).')),
(Literal.parse('~pred(X).'), {'X': 'a'}, Literal.parse('~pred(a).')),
(Literal.parse('~pred(X).'), {'Y': 'X'}, Literal.parse('~pred(X).')),
(Literal.parse('~pred(Y).'), {}, Literal.parse('~pred(Y).')),
(Literal.parse('~pred(Y).'), {'X': 'a'}, Literal.parse('~pred(Y).')),
(Literal.parse('~pred(Y).'), {'Y': 'X'}, Literal.parse('~pred(X).')),
(Literal.parse('~pred(X, Y).'), {}, Literal.parse('~pred(X, Y).')),
(Literal.parse('~pred(X, Y).'), {'X': 'a'}, Literal.parse('~pred(a, Y).')),
(Literal.parse('~pred(X, Y).'), {'Y': 'X'}, Literal.parse('~pred(X, X).')),
]):
clause, subst, expected = entry
with self.subTest(i=i, value=entry):
result = clause.substitute(subst)
assert_that(result, 'Clause.substitute(self, substitution: Substitution) -> Clause:') \
.is_equal_to(expected)
def test__parse(self):
for i, entry in enumerate([
('func.', Clause(Literal(Atom('func')))),
('func().', Clause(Literal(Atom('func', [])))),
('func(Var).', Clause(Literal(Atom('func', ['Var'])))),
('func(term).', Clause(Literal(Atom('func', ['term'])))),
('func(term, 5.0).', Clause(Literal(Atom('func', ['term', 5.0])))),
('func(term, 5.0, True).', Clause(Literal(Atom('func', ['term', 5.0, True])))),
('~func.', Clause(Literal(Atom('func'), True))),
('~func().', Clause(Literal(Atom('func', []), True))),
('~func(Var).', Clause(Literal(Atom('func', ['Var']), True))),
('~func(term).', Clause(Literal(Atom('func', ['term']), True))),
('~func(term, 5.0).', Clause(Literal(Atom('func', ['term', 5.0]), True))),
('~func(term, 5.0, True).', Clause(Literal(Atom('func', ['term', 5.0, True]), True))),
('func :- pred.', Clause(Literal(Atom('func')), [Literal(Atom('pred'))])),
('func() :- pred.', Clause(Literal(Atom('func', [])), [Literal(Atom('pred'))])),
('func(Var) :- pred.', Clause(Literal(Atom('func', ['Var'])), [Literal(Atom('pred'))])),
('func(term) :- pred.', Clause(Literal(Atom('func', ['term'])), [Literal(Atom('pred'))])),
('func(term, 5.0) :- pred.', Clause(Literal(Atom('func', ['term', 5.0])), [Literal(Atom('pred'))])),
('func(term, 5.0, True) :- pred.',
Clause(Literal(Atom('func', ['term', 5.0, True])), [Literal(Atom('pred'))])),
('~func :- pred.', Clause(Literal(Atom('func'), True), [Literal(Atom('pred'))])),
('~func() :- pred.', Clause(Literal(Atom('func', []), True), [Literal(Atom('pred'))])),
('~func(Var) :- pred.', Clause(Literal(Atom('func', ['Var']), True), [Literal(Atom('pred'))])),
('~func(term) :- pred.', Clause(Literal(Atom('func', ['term']), True), [Literal(Atom('pred'))])),
('~func(term, 5.0) :- pred.', Clause(Literal(Atom('func', ['term', 5.0]), True), [Literal(Atom('pred'))])),
('~func(term, 5.0, True) :- pred.',
Clause(Literal(Atom('func', ['term', 5.0, True]), True), [Literal(Atom('pred'))])),
]):
content, expected = entry
with self.subTest(i=i, value=entry):
result = Clause.parse(content)
assert_that(result, 'Clause.parse(content: str) -> Clause:') \
.is_equal_to(expected)
def test__unify(self):
for i, entry in enumerate([
(Literal.parse('func'),
Literal.parse('pred'),
None),
(Literal.parse('func'),
Literal.parse('func'),
{}),
(Literal.parse('func()'),
Literal.parse('pred()'),
None),
(Literal.parse('func()'),
Literal.parse('func()'),
{}),
(Literal.parse('func(term, 5.0)'),
Literal.parse('pred(term, 5.0)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('func(term, 5.0)'),
{}),
(Literal.parse('func(term, 5.0)'),
Literal.parse('pred(term, 5.0)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('func(term, 5.0)'),
{}),
(Literal.parse('func(term, 5.0)'),
Literal.parse('pred(5.0, term)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('func(5.0, term)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('pred(term)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('func(term)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('pred(5.0)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('func(5.0)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('pred(True)'),
None),
(Literal.parse('func(term, 5.0)'),
Literal.parse('func(True)'),
None),
(Literal.parse('func(term, V1, V2)'),
Literal.parse('pred(term, 5.0, True)'),
None),
(Literal.parse('func(term, V1, V2)'),
Literal.parse('func(term, 5.0, True)'),
{'V1': 5.0, 'V2': True}),
(Literal.parse('func(term, V1, V2)'),
Literal.parse('func(V0, 5.0, True)'),
{'V0': 'term', 'V1': 5.0, 'V2': True}),
(Literal.parse('func(term, 5.0, True)'),
Literal.parse('func(term, V1, V2)'),
{'V1': 5.0, 'V2': True}),
(Literal.parse('func(term, V1, V2)'),
Literal.parse('func(X, Y, Z)'),
{'X': 'term', 'Y': 'V1', 'Z': 'V2'}),
(Literal.parse('~func'),
Literal.parse('~pred'),
None),
(Literal.parse('~func'),
Literal.parse('~func'),
{}),
(Literal.parse('~func()'),
Literal.parse('~pred()'),
None),
(Literal.parse('~func()'),
Literal.parse('~func()'),
{}),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~pred(term, 5.0)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~func(term, 5.0)'),
{}),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~pred(term, 5.0)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~func(term, 5.0)'),
{}),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~pred(5.0, term)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~func(5.0, term)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~pred(term)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~func(term)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~pred(5.0)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~func(5.0)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~pred(True)'),
None),
(Literal.parse('~func(term, 5.0)'),
Literal.parse('~func(True)'),
None),
(Literal.parse('~func(term, V1, V2])'),
Literal.parse('~pred(term, 5.0, True)'),
None),
(Literal.parse('~func(term, V1, V2)'),
Literal.parse('~func(term, 5.0, True)'),
{'V1': 5.0, 'V2': True}),
(Literal.parse('~func(term, V1, V2)'),
Literal.parse('~func(V0, 5.0, True)'),
{'V0': 'term', 'V1': 5.0, 'V2': True}),
(Literal.parse('~func(term, 5.0, True)'),
Literal.parse('~func(term, V1, V2)'),
{'V1': 5.0, 'V2': True}),
(Literal.parse('~func(term, V1, V2)'),
Literal.parse('~func(X, Y, Z)'),
{'X': 'term', 'Y': 'V1', 'Z': 'V2'}),
]):
atom1, atom2, expected = entry
with self.subTest(i=i, value=entry):
result = atom1.unify(atom2)
assert_that(result, 'Literal.unify(self, other: Literal) -> Optional[Substitution]:') \
.is_equal_to(
expected)
def test__is_ground(self):
for i, entry in enumerate([
(Literal.parse('func'), True),
(Literal.parse('func()'), True),
(Literal.parse('func(term)'), True),
(Literal.parse('func(term, 5.0)'), True),
(Literal.parse('func(term, 5.0, True)'), True),
(Literal.parse('func(term, 5.0, True, Var)'), False),
(Literal.parse('func(term, 5.0, True, _anon)'), False),
(Literal.parse('~func'), True),
(Literal.parse('~func()'), True),
(Literal.parse('~func(term)'), True),
(Literal.parse('~func(term, 5.0)'), True),
(Literal.parse('~func(term, 5.0, True)'), True),
(Literal.parse('~func(term, 5.0, True, Var)'), False),
(Literal.parse('~func(term, 5.0, True, _anon)'), False),
]):
atom, expected = entry
with self.subTest(i=i, value=entry):
result = atom.is_ground()
assert_that(result, 'Literal.is_ground(self) -> bool:') \
.is_equal_to(expected)
def test__get_mask(self):
for i, entry in enumerate([
(Literal.parse('func'), Mask(False, 'func', 0)),
(Literal.parse('func()'), Mask(False, 'func', 0)),
(Literal.parse('func(term)'), Mask(False, 'func', 1)),
(Literal.parse('func(term, 5.0)'), Mask(False, 'func', 2)),
(Literal.parse('func(term, 5.0, True)'), Mask(False, 'func', 3)),
(Literal.parse('func(term, 5.0, True, X)'), Mask(False, 'func', 4)),
(Literal.parse('~func'), Mask(True, 'func', 0)),
(Literal.parse('~func()'), Mask(True, 'func', 0)),
(Literal.parse('~func(term)'), Mask(True, 'func', 1)),
(Literal.parse('~func(term, 5.0)'), Mask(True, 'func', 2)),
(Literal.parse('~func(term, 5.0, True)'), Mask(True, 'func', 3)),
(Literal.parse('~func(term, 5.0, True, X)'), Mask(True, 'func', 4)),
]):
literal, expected = entry
with self.subTest(i=i, value=entry):
result = literal.get_mask()
assert_that(result, 'Literal.get_mask(self) -> Mask:') \
.is_equal_to(expected)
def test__get_complement(self):
for i, entry in enumerate([
(Literal.parse('func'), Literal.parse('~func')),
(Literal.parse('func()'), Literal.parse('~func()')),
(Literal.parse('func(term)'), Literal.parse('~func(term)')),
(Literal.parse('func(term, 5.0)'), Literal.parse('~func(term, 5.0)')),
(Literal.parse('func(term, 5.0, True)'), Literal.parse('~func(term, 5.0, True)')),
(Literal.parse('func(term, 5.0, True, X)'), Literal.parse('~func(term, 5.0, True, X)')),
(Literal.parse('~func'), Literal.parse('func')),
(Literal.parse('~func()'), Literal.parse('func()')),
(Literal.parse('~func(term)'), Literal.parse('func(term)')),
(Literal.parse('~func(term, 5.0)'), Literal.parse('func(term, 5.0)')),
(Literal.parse('~func(term, 5.0, True)'), Literal.parse('func(term, 5.0, True)')),
(Literal.parse('~func(term, 5.0, True, X)'), Literal.parse('func(term, 5.0, True, X)')),
]):
literal, expected = entry
with self.subTest(i=i, value=entry):
result = literal.get_complement()
assert_that(result, 'Literal.get_complement(self) -> Literal:') \
.is_equal_to(expected)
def test__parse(self):
for i, entry in enumerate([
('func', Literal(Atom('func'))),
('func()', Literal(Atom('func', []))),
('func(term)', Literal(Atom('func', ['term']))),
('func(term, 5.0)', Literal(Atom('func', ['term', 5.0]))),
('func(term, 5.0, True)', Literal(Atom('func', ['term', 5.0, True]))),
('func(term, 5.0, True, X)', Literal(Atom('func', ['term', 5.0, True, 'X']))),
('~func', Literal(Atom('func'), True)),
('~func()', Literal(Atom('func', []), True)),
('~func(term)', Literal(Atom('func', ['term']), True)),
('~func(term, 5.0)', Literal(Atom('func', ['term', 5.0]), True)),
('~func(term, 5.0, True)', Literal(Atom('func', ['term', 5.0, True]), True)),
('~func(term, 5.0, True, X)', Literal(Atom('func', ['term', 5.0, True, 'X']), True)),
('~~func', Literal(Atom('func'))),
('~~func()', Literal(Atom('func', []))),
('~~func(term)', Literal(Atom('func', ['term']))),
('~~func(term, 5.0)', Literal(Atom('func', ['term', 5.0]))),
('~~func(term, 5.0, True)', Literal(Atom('func', ['term', 5.0, True]))),
('~~func(term, 5.0, True, X)', Literal(Atom('func', ['term', 5.0, True, 'X']))),
('~~~func', Literal(Atom('func'), True)),
('~~~func()', Literal(Atom('func', []), True)),
('~~~func(term)', Literal(Atom('func', ['term']), True)),
('~~~func(term, 5.0)', Literal(Atom('func', ['term', 5.0]), True)),
('~~~func(term, 5.0, True)', Literal(Atom('func', ['term', 5.0, True]), True)),
('~~~func(term, 5.0, True, X)', Literal(Atom('func', ['term', 5.0, True, 'X']), True)),
]):
content, expected = entry
with self.subTest(i=i, value=entry):
result = Literal.parse(content)
assert_that(result, 'Literal.parse(content: str) -> Literal:') \
.is_equal_to(expected)
from foil.learning import get_masks
from foil.learning import get_signature
from foil.learning import get_table
from foil.learning import Hypothesis
from foil.learning import itemize
from foil.learning import max_gain
from foil.models import Clause
from foil.models import Example
from foil.models import Literal
from foil.models import Mask
from foil.models import Program
hypotheses_0 = []
hypotheses_1 = [Clause.parse('path(X,Y) :- edge(X,Y).')]
target = Literal.parse('path(X,Y)')
body_0 = []
body_1 = [Literal.parse('edge(X,V0)')]
edge_x_y = Literal.parse('edge(X,Y)')
edge_x_v0 = Literal.parse('edge(X,V0)')
path_v0_y = Literal.parse('path(V0,Y)')
edge_v0_y = Literal.parse('edge(V0,Y)')
background = [
Clause.parse('edge(0,1).'),
Clause.parse('edge(0,3).'),
Clause.parse('edge(1,2).'),
Clause.parse('edge(3,2).'),
Clause.parse('edge(3,4).'),
from foil.models import Example
from foil.models import Label
from foil.models import Literal
from foil.models import Problem
from foil.models import Program
if __name__ == '__main__':
problem = Problem(
Program.parse('edge(0,1). edge(0,3). edge(1,2). edge(3,2). edge(3,4). '
'edge(4,5). edge(4,6). edge(6,8). edge(7,6). edge(7,8).'),
Literal.parse('path(X,Y)'),
[
Example({'X': 0, 'Y': 1}, Label.POSITIVE),
Example({'X': 0, 'Y': 2}, Label.POSITIVE),
Example({'X': 0, 'Y': 3}, Label.POSITIVE),
Example({'X': 0, 'Y': 4}, Label.POSITIVE),
Example({'X': 0, 'Y': 5}, Label.POSITIVE),
Example({'X': 0, 'Y': 6}, Label.POSITIVE),
Example({'X': 0, 'Y': 8}, Label.POSITIVE),
Example({'X': 1, 'Y': 2}, Label.POSITIVE),
Example({'X': 3, 'Y': 2}, Label.POSITIVE),
Example({'X': 3, 'Y': 4}, Label.POSITIVE),
Example({'X': 3, 'Y': 5}, Label.POSITIVE),
Example({'X': 3, 'Y': 6}, Label.POSITIVE),
Example({'X': 3, 'Y': 8}, Label.POSITIVE),
Example({'X': 4, 'Y': 5}, Label.POSITIVE),
Example({'X': 4, 'Y': 6}, Label.POSITIVE),
Example({'X': 4, 'Y': 8}, Label.POSITIVE),
Example({'X': 6, 'Y': 8}, Label.POSITIVE),
Example({'X': 7, 'Y': 6}, Label.POSITIVE),
Example({'X': 7, 'Y': 8}, Label.POSITIVE),
from foil.models import Program
class Measure:
def __init__(self):
self.elapsed = None
def __enter__(self):
self.elapsed = datetime.datetime.now()
def __exit__(self, ty, val, tb):
print('\nElapsed time: %s sec.\n' % (datetime.datetime.now() - self.elapsed))
if __name__ == '__main__':
target = Literal.parse('path(X,Y)')
examples = [
Example({'X': 0, 'Y': 1}), Example({'X': 0, 'Y': 2}), Example({'X': 0, 'Y': 3}),
Example({'X': 0, 'Y': 4}), Example({'X': 0, 'Y': 5}), Example({'X': 0, 'Y': 6}),
Example({'X': 0, 'Y': 8}), Example({'X': 1, 'Y': 2}), Example({'X': 3, 'Y': 2}),
Example({'X': 3, 'Y': 4}), Example({'X': 3, 'Y': 5}), Example({'X': 3, 'Y': 6}),
Example({'X': 3, 'Y': 8}), Example({'X': 4, 'Y': 5}), Example({'X': 4, 'Y': 6}),
Example({'X': 4, 'Y': 8}), Example({'X': 6, 'Y': 8}), Example({'X': 7, 'Y': 6}),
Example({'X': 7, 'Y': 8}),
]
background = [
Clause.parse('edge(0,1).'), Clause.parse('edge(0,3).'), Clause.parse('edge(1,2).'),
Clause.parse('edge(3,2).'), Clause.parse('edge(3,4).'), Clause.parse('edge(4,5).'),
Clause.parse('edge(4,6).'), Clause.parse('edge(6,8).'), Clause.parse('edge(7,6).'),
Clause.parse('edge(7,8).'),
]
from foil.models import Literal
from foil.models import Program
source = """
q(X,Y) :- p(Y,X).
p(1,2).
"""
if __name__ == '__main__':
program = Program.parse(source)
print(program)
print()
query = Literal.parse('q(2,1)')
print('?-', query)
derivation = program.resolve(query)
if derivation:
print('YES')
for step in derivation:
clause = program.get_clause(step.index)
subst = '{%s}' % ', '.join('%s: %s' % (k, repr(v)) for k, v in step.substitution.items())
print(' ', clause, ' / ', subst, ' / ', step.literal)
else:
print('NO')
print()
print('Done.')
