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| from sympy.strategies.tree import treeapply, greedy, allresults, brute | |
| from functools import partial, reduce | |
| def inc(x): | |
| return x + 1 | |
| def dec(x): | |
| return x - 1 | |
| def double(x): | |
| return 2 * x | |
| def square(x): | |
| return x**2 | |
| def add(*args): | |
| return sum(args) | |
| def mul(*args): | |
| return reduce(lambda a, b: a * b, args, 1) | |
| def test_treeapply(): | |
| tree = ([3, 3], [4, 1], 2) | |
| assert treeapply(tree, {list: min, tuple: max}) == 3 | |
| assert treeapply(tree, {list: add, tuple: mul}) == 60 | |
| def test_treeapply_leaf(): | |
| assert treeapply(3, {}, leaf=lambda x: x**2) == 9 | |
| tree = ([3, 3], [4, 1], 2) | |
| treep1 = ([4, 4], [5, 2], 3) | |
| assert treeapply(tree, {list: min, tuple: max}, leaf=lambda x: x + 1) == \ | |
| treeapply(treep1, {list: min, tuple: max}) | |
| def test_treeapply_strategies(): | |
| from sympy.strategies import chain, minimize | |
| join = {list: chain, tuple: minimize} | |
| assert treeapply(inc, join) == inc | |
| assert treeapply((inc, dec), join)(5) == minimize(inc, dec)(5) | |
| assert treeapply([inc, dec], join)(5) == chain(inc, dec)(5) | |
| tree = (inc, [dec, double]) # either inc or dec-then-double | |
| assert treeapply(tree, join)(5) == 6 | |
| assert treeapply(tree, join)(1) == 0 | |
| maximize = partial(minimize, objective=lambda x: -x) | |
| join = {list: chain, tuple: maximize} | |
| fn = treeapply(tree, join) | |
| assert fn(4) == 6 # highest value comes from the dec then double | |
| assert fn(1) == 2 # highest value comes from the inc | |
| def test_greedy(): | |
| tree = [inc, (dec, double)] # either inc or dec-then-double | |
| fn = greedy(tree, objective=lambda x: -x) | |
| assert fn(4) == 6 # highest value comes from the dec then double | |
| assert fn(1) == 2 # highest value comes from the inc | |
| tree = [inc, dec, [inc, dec, [(inc, inc), (dec, dec)]]] | |
| lowest = greedy(tree) | |
| assert lowest(10) == 8 | |
| highest = greedy(tree, objective=lambda x: -x) | |
| assert highest(10) == 12 | |
| def test_allresults(): | |
| # square = lambda x: x**2 | |
| assert set(allresults(inc)(3)) == {inc(3)} | |
| assert set(allresults([inc, dec])(3)) == {2, 4} | |
| assert set(allresults((inc, dec))(3)) == {3} | |
| assert set(allresults([inc, (dec, double)])(4)) == {5, 6} | |
| def test_brute(): | |
| tree = ([inc, dec], square) | |
| fn = brute(tree, lambda x: -x) | |
| assert fn(2) == (2 + 1)**2 | |
| assert fn(-2) == (-2 - 1)**2 | |
| assert brute(inc)(1) == 2 | |