def test_wilds_in_wilds():
from sympy import MatrixSymbol, MatMul
A = MatrixSymbol('A', n, m)
B = MatrixSymbol('B', m, k)
pattern = patternify(A * B, 'A', n, m, B) # note that m is in B as well
assert deconstruct(pattern) == Compound(
MatMul,
(Compound(MatrixSymbol,
(Variable('A'), Variable(n), Variable(m))), Variable(B)))
def test_deconstruct():
expr = Basic(1, 2, 3)
expected = Compound(Basic, (1, 2, 3))
assert deconstruct(expr) == expected
assert deconstruct(1) == 1
assert deconstruct(x) == x
assert deconstruct(x, variables=(x, )) == Variable(x)
assert deconstruct(Add(1, x, evaluate=False)) == Compound(Add, (1, x))
assert deconstruct(Add(1, x, evaluate=False), variables=(x,)) == \
Compound(Add, (1, Variable(x)))
def deconstruct(s):
""" Turn a SymPy object into a Compound """
if isinstance(s, ExprWild):
return Variable(s)
if isinstance(s, (Variable, CondVariable)):
return s
if not isinstance(s, Basic) or s.is_Atom:
return s
return Compound(s.__class__, tuple(map(deconstruct, s.args)))
def deconstruct(s, variables=()):
""" Turn a SymPy object into a Compound """
if s in variables:
return Variable(s)
if isinstance(s, (Variable, CondVariable)):
return s
if not isinstance(s, Basic) or s.is_Atom:
return s
return Compound(s.__class__,
tuple(deconstruct(arg, variables) for arg in s.args))
def test_nested():
expr = Basic(1, Basic(2), 3)
cmpd = Compound(Basic, (1, Compound(Basic, (2, )), 3))
assert deconstruct(expr) == cmpd
assert construct(cmpd) == expr
def test_construct():
expr = Compound(Basic, (1, 2, 3))
expected = Basic(1, 2, 3)
assert construct(expr) == expected
def test_commutativity():
c1 = Compound('CAdd', (a, b))
c2 = Compound('CAdd', (x, y))
assert is_commutative(c1) and is_commutative(c2)
assert len(list(unify(c1, c2, {}))) == 2
def test_nested():
expr = Basic(S(1), Basic(S(2)), S(3))
cmpd = Compound(Basic, (S(1), Compound(Basic, Tuple(2)), S(3)))
assert deconstruct(expr) == cmpd
assert construct(cmpd) == expr
def test_construct():
expr = Compound(Basic, (S(1), S(2), S(3)))
expected = Basic(S(1), S(2), S(3))
assert construct(expr) == expected
def test_deconstruct():
expr = Basic(1, 2, 3)
expected = Compound(Basic, (1, 2, 3))
assert deconstruct(expr) == expected
def test_patternify():
assert deconstruct(patternify(x + y,
x)) in (Compound(Add, (Variable(x), y)),
Compound(Add, (y, Variable(x))))
pattern = patternify(x**2 + y**2, x)
assert list(unify(pattern, w**2 + y**2, {})) == [{x: w}]