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| from sympy.unify.core import Compound, Variable, CondVariable, allcombinations | |
| from sympy.unify import core | |
| a,b,c = 'a', 'b', 'c' | |
| w,x,y,z = map(Variable, 'wxyz') | |
| C = Compound | |
| def is_associative(x): | |
| return isinstance(x, Compound) and (x.op in ('Add', 'Mul', 'CAdd', 'CMul')) | |
| def is_commutative(x): | |
| return isinstance(x, Compound) and (x.op in ('CAdd', 'CMul')) | |
| def unify(a, b, s={}): | |
| return core.unify(a, b, s=s, is_associative=is_associative, | |
| is_commutative=is_commutative) | |
| def test_basic(): | |
| assert list(unify(a, x, {})) == [{x: a}] | |
| assert list(unify(a, x, {x: 10})) == [] | |
| assert list(unify(1, x, {})) == [{x: 1}] | |
| assert list(unify(a, a, {})) == [{}] | |
| assert list(unify((w, x), (y, z), {})) == [{w: y, x: z}] | |
| assert list(unify(x, (a, b), {})) == [{x: (a, b)}] | |
| assert list(unify((a, b), (x, x), {})) == [] | |
| assert list(unify((y, z), (x, x), {}))!= [] | |
| assert list(unify((a, (b, c)), (a, (x, y)), {})) == [{x: b, y: c}] | |
| def test_ops(): | |
| assert list(unify(C('Add', (a,b,c)), C('Add', (a,x,y)), {})) == \ | |
| [{x:b, y:c}] | |
| assert list(unify(C('Add', (C('Mul', (1,2)), b,c)), C('Add', (x,y,c)), {})) == \ | |
| [{x: C('Mul', (1,2)), y:b}] | |
| def test_associative(): | |
| c1 = C('Add', (1,2,3)) | |
| c2 = C('Add', (x,y)) | |
| assert tuple(unify(c1, c2, {})) == ({x: 1, y: C('Add', (2, 3))}, | |
| {x: C('Add', (1, 2)), y: 3}) | |
| def test_commutative(): | |
| c1 = C('CAdd', (1,2,3)) | |
| c2 = C('CAdd', (x,y)) | |
| result = list(unify(c1, c2, {})) | |
| assert {x: 1, y: C('CAdd', (2, 3))} in result | |
| assert ({x: 2, y: C('CAdd', (1, 3))} in result or | |
| {x: 2, y: C('CAdd', (3, 1))} in result) | |
| def _test_combinations_assoc(): | |
| assert set(allcombinations((1,2,3), (a,b), True)) == \ | |
| {(((1, 2), (3,)), (a, b)), (((1,), (2, 3)), (a, b))} | |
| def _test_combinations_comm(): | |
| assert set(allcombinations((1,2,3), (a,b), None)) == \ | |
| {(((1,), (2, 3)), ('a', 'b')), (((2,), (3, 1)), ('a', 'b')), | |
| (((3,), (1, 2)), ('a', 'b')), (((1, 2), (3,)), ('a', 'b')), | |
| (((2, 3), (1,)), ('a', 'b')), (((3, 1), (2,)), ('a', 'b'))} | |
| def test_allcombinations(): | |
| assert set(allcombinations((1,2), (1,2), 'commutative')) ==\ | |
| {(((1,),(2,)), ((1,),(2,))), (((1,),(2,)), ((2,),(1,)))} | |
| 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_CondVariable(): | |
| expr = C('CAdd', (1, 2)) | |
| x = Variable('x') | |
| y = CondVariable('y', lambda a: a % 2 == 0) | |
| z = CondVariable('z', lambda a: a > 3) | |
| pattern = C('CAdd', (x, y)) | |
| assert list(unify(expr, pattern, {})) == \ | |
| [{x: 1, y: 2}] | |
| z = CondVariable('z', lambda a: a > 3) | |
| pattern = C('CAdd', (z, y)) | |
| assert list(unify(expr, pattern, {})) == [] | |
| def test_defaultdict(): | |
| assert next(unify(Variable('x'), 'foo')) == {Variable('x'): 'foo'} | |