def test_flattener_value_of():
flattener = flatten_expressions._ParamFlattener({'c': 5, 'x1': 'x1'})
assert flattener.value_of(9) == 9
assert flattener.value_of('c') == 5
assert flattener.value_of(sympy.Symbol('c')) == 5
# Twice
assert (flattener.value_of(sympy.Symbol('c') / 2 +
1) == sympy.Symbol('<c/2 + 1>'))
assert (flattener.value_of(sympy.Symbol('c') / 2 +
1) == sympy.Symbol('<c/2 + 1>'))
# Collisions between the string representation of different expressions
# This tests the unusual case where str(expr1) == str(expr2) doesn't imply
# expr1 == expr2. In this case it would be incorrect to flatten to the same
# symbol because the two expression will evaluate to different values.
# Also tests that '_#' is appended when avoiding collisions.
assert (flattener.value_of(
sympy.Symbol('c') /
sympy.Symbol('2 + 1')) == sympy.Symbol('<c/2 + 1>_1'))
assert (flattener.value_of(sympy.Symbol('c/2') +
1) == sympy.Symbol('<c/2 + 1>_2'))
assert (cirq.flatten([sympy.Symbol('c') / 2 + 1,
sympy.Symbol('c/2') + 1])[0] == [
sympy.Symbol('<c/2 + 1>'),
sympy.Symbol('<c/2 + 1>_1')
])
def test_flatten_circuit():
qubit = cirq.LineQubit(0)
a = sympy.Symbol('a')
circuit = cirq.Circuit(cirq.X(qubit)**a, cirq.X(qubit)**(1 + a / 2))
c_flat, expr_map = cirq.flatten(circuit)
c_expected = cirq.Circuit(
cirq.X(qubit)**a,
cirq.X(qubit)**sympy.Symbol('<a/2 + 1>'))
assert c_flat == c_expected
assert isinstance(expr_map, cirq.ExpressionMap)
assert expr_map == {a: a, 1 + a / 2: sympy.Symbol('<a/2 + 1>')}
