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from sympy.core.add import Add
from sympy.core.basic import Basic
from sympy.core.containers import Tuple
from sympy.core.singleton import S
from sympy.core.symbol import (Symbol, symbols)
from sympy.logic.boolalg import And
from sympy.core.symbol import Str
from sympy.unify.core import Compound, Variable
from sympy.unify.usympy import (deconstruct, construct, unify, is_associative,
is_commutative)
from sympy.abc import x, y, z, n
def test_deconstruct():
expr = Basic(S(1), S(2), S(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 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_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_unify():
expr = Basic(S(1), S(2), S(3))
a, b, c = map(Symbol, 'abc')
pattern = Basic(a, b, c)
assert list(unify(expr, pattern, {}, (a, b, c))) == [{a: 1, b: 2, c: 3}]
assert list(unify(expr, pattern, variables=(a, b, c))) == \
[{a: 1, b: 2, c: 3}]
def test_unify_variables():
assert list(unify(Basic(S(1), S(2)), Basic(S(1), x), {}, variables=(x,))) == [{x: 2}]
def test_s_input():
expr = Basic(S(1), S(2))
a, b = map(Symbol, 'ab')
pattern = Basic(a, b)
assert list(unify(expr, pattern, {}, (a, b))) == [{a: 1, b: 2}]
assert list(unify(expr, pattern, {a: 5}, (a, b))) == []
def iterdicteq(a, b):
a = tuple(a)
b = tuple(b)
return len(a) == len(b) and all(x in b for x in a)
def test_unify_commutative():
expr = Add(1, 2, 3, evaluate=False)
a, b, c = map(Symbol, 'abc')
pattern = Add(a, b, c, evaluate=False)
result = tuple(unify(expr, pattern, {}, (a, b, c)))
expected = ({a: 1, b: 2, c: 3},
{a: 1, b: 3, c: 2},
{a: 2, b: 1, c: 3},
{a: 2, b: 3, c: 1},
{a: 3, b: 1, c: 2},
{a: 3, b: 2, c: 1})
assert iterdicteq(result, expected)
def test_unify_iter():
expr = Add(1, 2, 3, evaluate=False)
a, b, c = map(Symbol, 'abc')
pattern = Add(a, c, evaluate=False)
assert is_associative(deconstruct(pattern))
assert is_commutative(deconstruct(pattern))
result = list(unify(expr, pattern, {}, (a, c)))
expected = [{a: 1, c: Add(2, 3, evaluate=False)},
{a: 1, c: Add(3, 2, evaluate=False)},
{a: 2, c: Add(1, 3, evaluate=False)},
{a: 2, c: Add(3, 1, evaluate=False)},
{a: 3, c: Add(1, 2, evaluate=False)},
{a: 3, c: Add(2, 1, evaluate=False)},
{a: Add(1, 2, evaluate=False), c: 3},
{a: Add(2, 1, evaluate=False), c: 3},
{a: Add(1, 3, evaluate=False), c: 2},
{a: Add(3, 1, evaluate=False), c: 2},
{a: Add(2, 3, evaluate=False), c: 1},
{a: Add(3, 2, evaluate=False), c: 1}]
assert iterdicteq(result, expected)
def test_hard_match():
from sympy.functions.elementary.trigonometric import (cos, sin)
expr = sin(x) + cos(x)**2
p, q = map(Symbol, 'pq')
pattern = sin(p) + cos(p)**2
assert list(unify(expr, pattern, {}, (p, q))) == [{p: x}]
def test_matrix():
from sympy.matrices.expressions.matexpr import MatrixSymbol
X = MatrixSymbol('X', n, n)
Y = MatrixSymbol('Y', 2, 2)
Z = MatrixSymbol('Z', 2, 3)
assert list(unify(X, Y, {}, variables=[n, Str('X')])) == [{Str('X'): Str('Y'), n: 2}]
assert list(unify(X, Z, {}, variables=[n, Str('X')])) == []
def test_non_frankenAdds():
# the is_commutative property used to fail because of Basic.__new__
# This caused is_commutative and str calls to fail
expr = x+y*2
rebuilt = construct(deconstruct(expr))
# Ensure that we can run these commands without causing an error
str(rebuilt)
rebuilt.is_commutative
def test_FiniteSet_commutivity():
from sympy.sets.sets import FiniteSet
a, b, c, x, y = symbols('a,b,c,x,y')
s = FiniteSet(a, b, c)
t = FiniteSet(x, y)
variables = (x, y)
assert {x: FiniteSet(a, c), y: b} in tuple(unify(s, t, variables=variables))
def test_FiniteSet_complex():
from sympy.sets.sets import FiniteSet
a, b, c, x, y, z = symbols('a,b,c,x,y,z')
expr = FiniteSet(Basic(S(1), x), y, Basic(x, z))
pattern = FiniteSet(a, Basic(x, b))
variables = a, b
expected = ({b: 1, a: FiniteSet(y, Basic(x, z))},
{b: z, a: FiniteSet(y, Basic(S(1), x))})
assert iterdicteq(unify(expr, pattern, variables=variables), expected)
def test_and():
variables = x, y
expected = ({x: z > 0, y: n < 3},)
assert iterdicteq(unify((z>0) & (n<3), And(x, y), variables=variables),
expected)
def test_Union():
from sympy.sets.sets import Interval
assert list(unify(Interval(0, 1) + Interval(10, 11),
Interval(0, 1) + Interval(12, 13),
variables=(Interval(12, 13),)))
def test_is_commutative():
assert is_commutative(deconstruct(x+y))
assert is_commutative(deconstruct(x*y))
assert not is_commutative(deconstruct(x**y))
def test_commutative_in_commutative():
from sympy.abc import a,b,c,d
from sympy.functions.elementary.trigonometric import (cos, sin)
eq = sin(3)*sin(4)*sin(5) + 4*cos(3)*cos(4)
pat = a*cos(b)*cos(c) + d*sin(b)*sin(c)
assert next(unify(eq, pat, variables=(a,b,c,d)))