def __and__(self, other):
"""Parallel composition of runnable components returns new Branches."""
if isinstance(other, Branches):
return Branches(self, *other)
elif isinstance(other, Runnable):
return Branches(self, other)
else:
raise TypeError("only Runnables can be composed into Branches")
def test_look_and_feel(self):
br = Runnable(), Runnable()
pb = Branches(*br)
self.assertEqual(pb.name, 'Branches')
self.assertEqual(str(pb), '(Runnable) & (Runnable)')
self.assertEqual(repr(pb), 'Branches(Runnable(), Runnable())')
self.assertEqual(tuple(pb), br)
def test_continuity(self):
class Fast(Runnable):
def next(self, state):
time.sleep(0.1)
return state.updated(x=state.x + 1)
class Slow(Runnable):
def next(self, state):
time.sleep(0.2)
return state.updated(x=state.x + 2)
bs = Branches(Slow(), Fast(), Slow())
ss = States(*[State(x=0) for _ in range(3)])
res = bs.run(ss).result()
self.assertEqual([s.x for s in res], [2, 1, 2])
def test_parallel_independent_execution(self):
class Component(Runnable):
def __init__(self, runtime):
super(Component, self).__init__()
self.runtime = runtime
def next(self, state):
time.sleep(self.runtime)
return state
# make sure all branches really run in parallel
n = 5
bs = Branches(*[Component(1) for _ in range(n)])
ss = States(*[State() for _ in range(n)])
with tictoc() as tt:
bs.run(ss).result()
# total runtime has to be smaller that the sum of individual runtimes
self.assertTrue(1 <= tt.dt <= 2)
def test_composition(self):
class A(Runnable):
def next(self, state):
return state.updated(x=state.x + 1)
class B(Runnable):
def next(self, state):
return state.updated(x=state.x * 7)
a, b = A(), B()
# single branch
b1 = Branches(a)
ss = States(State(x=1))
res = b1.run(ss).result()
self.assertEqual(b1.branches, (a, ))
self.assertEqual(len(res), 1)
self.assertEqual(res[0].x, ss[0].x + 1)
# two branches, explicit and implicit construction
for b2 in [Branches(a, b), a & b]:
ss = States(State(x=1), State(x=1))
res = b2.run(ss).result()
self.assertEqual(b2.branches, (a, b))
self.assertEqual(len(res), 2)
self.assertEqual(res[0].x, ss[0].x + 1)
self.assertEqual(res[1].x, ss[1].x * 7)
# appending a branch to branches
b3 = b2 & a
ss = States(*[State(x=1) for _ in range(3)])
res = b3.run(ss).result()
self.assertEqual(b3.branches, (a, b, a))
self.assertEqual(len(res), 3)
self.assertEqual(res[0].x, ss[0].x + 1)
self.assertEqual(res[1].x, ss[1].x * 7)
self.assertEqual(res[2].x, ss[2].x + 1)
# prepending a branch to branches
b4 = b & b2
ss = States(*[State(x=1) for _ in range(3)])
res = b4.run(ss).result()
self.assertEqual(b4.branches, (b, a, b))
self.assertEqual(len(res), 3)
self.assertEqual(res[0].x, ss[0].x * 7)
self.assertEqual(res[1].x, ss[1].x + 1)
self.assertEqual(res[2].x, ss[2].x * 7)
# invalid type
with self.assertRaises(TypeError):
b & 1
with self.assertRaises(TypeError):
b1 & 1
def test_empty(self):
with self.assertRaises(ValueError):
Branches()