def test_different_constraints_on_commutative_operation():
c1 = CustomConstraint(lambda x: len(str(x)) > 1)
c2 = CustomConstraint(lambda x: len(str(x)) == 1)
pattern1 = Pattern(f_c(x_), c1)
pattern2 = Pattern(f_c(x_), c2)
pattern3 = Pattern(f_c(x_, b), c1)
pattern4 = Pattern(f_c(x_, b), c2)
matcher = ManyToOneMatcher(pattern1, pattern2, pattern3, pattern4)
subject = f_c(a)
results = list(matcher.match(subject))
assert len(results) == 1
assert results[0][0] == pattern2
assert results[0][1] == {'x': a}
subject = f_c(Symbol('longer'), b)
results = sorted(matcher.match(subject))
assert len(results) == 1
assert results[0][0] == pattern3
assert results[0][1] == {'x': Symbol('longer')}
subject = f_c(a, b)
results = list(matcher.match(subject))
assert len(results) == 1
assert results[0][0] == pattern4
assert results[0][1] == {'x': a}
def test_add_duplicate_pattern():
pattern = Pattern(f(a))
matcher = ManyToOneMatcher()
matcher.add(pattern)
matcher.add(pattern)
assert len(matcher.patterns) == 1
def test_add_duplicate_pattern_with_different_constraint():
pattern1 = Pattern(f(a))
pattern2 = Pattern(f(a), MockConstraint(False))
matcher = ManyToOneMatcher()
matcher.add(pattern1)
matcher.add(pattern2)
assert len(matcher.patterns) == 2
def test_different_constraints_no_match_on_operation():
c1 = CustomConstraint(lambda x: x == a)
c2 = CustomConstraint(lambda x: x == b)
pattern1 = Pattern(f(x_), c1)
pattern2 = Pattern(f(x_), c2)
matcher = ManyToOneMatcher(pattern1, pattern2)
subject = f(c)
results = list(matcher.match(subject))
assert len(results) == 0
def test_same_pattern_different_label():
pattern = Pattern(a)
matcher = ManyToOneMatcher()
matcher.add(pattern, 42)
matcher.add(pattern, 23)
result = sorted(
(l, sorted(map(tuple, s.items()))) for l, s in matcher.match(a))
assert result == [(23, []), (42, [])]
def test_same_commutative_but_different_pattern():
pattern1 = Pattern(f(f_c(x_), a))
pattern2 = Pattern(f(f_c(x_), b))
matcher = ManyToOneMatcher(pattern1, pattern2)
subject = f(f_c(a), a)
result = list(matcher.match(subject))
assert result == [(pattern1, {'x': a})]
subject = f(f_c(a), b)
result = list(matcher.match(subject))
assert result == [(pattern2, {'x': a})]
def match_many_to_one(expression, *patterns):
try:
pattern = patterns[0]
commutative = next(
p for p in preorder_iter(pattern.expression) if isinstance(p, CommutativeOperation)
)
next(wc for wc in preorder_iter(commutative) if isinstance(wc, Wildcard) and wc.min_count > 1)
except StopIteration:
pass
else:
pytest.xfail('Matcher does not support fixed wildcards with length != 1 in commutative operations')
matcher = ManyToOneMatcher(*patterns)
for _, substitution in matcher.match(expression):
yield substitution
def test_code_generation_many_to_one(subject, patterns):
patterns = [Pattern(p) for p in patterns]
matcher = ManyToOneMatcher(*patterns)
generator = CodeGenerator(matcher)
gc, code = generator.generate_code()
code = GENERATED_TEMPLATE.format(gc, code)
compiled = compile(code, '', 'exec')
module = ModuleType('generated_code')
print('=' * 80)
print(code)
print('=' * 80)
exec(compiled, module.__dict__)
for pattern in patterns:
print(pattern)
matches = list(module.match_root(subject))
for i, pattern in enumerate(patterns):
expected_matches = PARAM_MATCHES[subject, pattern.expression]
for expected_match in expected_matches:
assert (
i, expected_match
) in matches, "Subject {!s} and pattern {!s} did not yield the match {!s} but were supposed to".format(
subject, pattern, expected_match)
while (i, expected_match) in matches:
matches.remove((i, expected_match))
assert matches == [], "Subject {!s} and pattern {!s} yielded unexpected matches".format(
subject, pattern)
def test_many_to_one(subject, patterns):
patterns = [Pattern(p) for p in patterns]
matcher = ManyToOneMatcher(*patterns)
matches = list(matcher.match(subject))
for pattern in patterns:
expected_matches = PARAM_MATCHES[subject, pattern.expression]
for expected_match in expected_matches:
assert (
pattern, expected_match
) in matches, "Subject {!s} and pattern {!s} did not yield the match {!s} but were supposed to".format(
subject, pattern, expected_match)
while (pattern, expected_match) in matches:
matches.remove((pattern, expected_match))
assert matches == [], "Subject {!s} and pattern {!s} yielded unexpected matches".format(
subject, pattern)
def test_grouped():
pattern1 = Pattern(a, MockConstraint(True))
pattern2 = Pattern(a, MockConstraint(True))
pattern3 = Pattern(x_, MockConstraint(True))
matcher = ManyToOneMatcher(pattern1, pattern2, pattern3)
result = [[p for p, _ in ps] for ps in matcher.match(a).grouped()]
assert len(result) == 2
for res in result:
if len(res) == 2:
assert pattern1 in res
assert pattern2 in res
elif len(res) == 1:
assert pattern3 in res
else:
assert False, "Wrong number of grouped matches"
def test_different_pattern_same_constraint(c1, c2):
constr1 = CustomConstraint(lambda x: c1)
constr2 = CustomConstraint(lambda x: c2)
constr3 = CustomConstraint(lambda x: True)
patterns = [
Pattern(f2(x_, a), constr3),
Pattern(f(a, a, x_), constr3),
Pattern(f(a, x_), constr1),
Pattern(f(x_, a), constr2),
Pattern(f(a, x_, b), constr1),
Pattern(f(x_, a, b), constr1),
]
subject = f(a, a)
matcher = ManyToOneMatcher(*patterns)
results = list(matcher.match(subject))
assert len(results) == int(c1) + int(c2)
def test_different_pattern_different_label():
matcher = ManyToOneMatcher()
matcher.add(Pattern(a), 42)
matcher.add(Pattern(x_), 23)
result = sorted(
(l, sorted(map(tuple, s.items()))) for l, s in matcher.match(a))
assert result == [(23, [('x', a)]), (42, [])]
def match_generated(expression, pattern):
matcher = ManyToOneMatcher(pattern)
generator = CodeGenerator(matcher)
gc, code = generator.generate_code()
code = GENERATED_TEMPLATE.format(gc, code)
compiled = compile(code, '', 'exec')
module = ModuleType("generated_code")
print(code)
exec(compiled, module.__dict__)
for _, substitution in module.match_root(expression):
yield substitution
def test_one_identity_optional_commutativity():
Int = Operation.new('Int', Arity.binary)
Add = Operation.new('+',
Arity.variadic,
'Add',
infix=True,
associative=True,
commutative=True,
one_identity=True)
Mul = Operation.new('*',
Arity.variadic,
'Mul',
infix=True,
associative=True,
commutative=True,
one_identity=True)
Pow = Operation.new('^', Arity.binary, 'Pow', infix=True)
class Integer(Symbol):
def __init__(self, value):
super().__init__(str(value))
i0 = Integer(0)
i1 = Integer(1)
i2 = Integer(2)
x_, m_, a_ = map(Wildcard.dot, 'xma')
x, m = map(Symbol, 'xm')
a0_ = Wildcard.optional('a', i0)
b1_ = Wildcard.optional('b', i1)
c0_ = Wildcard.optional('c', i0)
d1_ = Wildcard.optional('d', i1)
m1_ = Wildcard.optional('m', i1)
n1_ = Wildcard.optional('n', i1)
pattern22 = Pattern(
Int(
Mul(Pow(Add(a0_, Mul(b1_, x_)), m1_),
Pow(Add(c0_, Mul(d1_, x_)), n1_)), x_))
pattern23 = Pattern(
Int(
Mul(Pow(Add(a_, Mul(b1_, x_)), m1_),
Pow(Add(c0_, Mul(d1_, x_)), n1_)), x_))
matcher = ManyToOneMatcher()
matcher.add(pattern22, 22)
matcher.add(pattern23, 23)
subject = Int(Mul(Pow(Add(Mul(b, x), a), i2), Pow(x, i2)), x)
result = sorted(
(l, sorted(map(tuple, s.items()))) for l, s in matcher.match(subject))
assert result == [
(22, [('a', i0), ('b', i1), ('c', a), ('d', b), ('m', i2), ('n', i2),
('x', x)]),
(22, [('a', a), ('b', b), ('c', i0), ('d', i1), ('m', i2), ('n', i2),
('x', x)]),
(23, [('a', a), ('b', b), ('c', i0), ('d', i1), ('m', i2), ('n', i2),
('x', x)]),
]