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