Quantum Switch Case#

qswitch(operand, case, case_function_list, method='sequential')[source]#

Executes a switch - case statement distinguishing between a list of given in-place functions.

Parameters:

operandQuantumVariable: The quantum argument on which to execute the case function.
caseQuantumFloat: A QuantumFloat specifying which case function should be executed.
case_function_listlist[callable]: A list of functions, performing some in-place operation on operand.
methodstr, optional: The compilation method. Available are parallel and sequential. parallel is exponentially fast but requires more temporary qubits. The default is “sequential”.

Examples

We create some sample functions:

>>> from qrisp import *
>>> def f0(x): x += 1
>>> def f1(x): inpl_mult(x, 3, treat_overflow = False)
>>> def f2(x): pass
>>> def f3(x): h(x[1])
>>> case_function_list = [f0, f1, f2, f3]

Create operand and case variable

>>> operand = QuantumFloat(4)
>>> operand[:] = 1
>>> case = QuantumFloat(2)
>>> h(case)

Execute switch_case function

>>> qswitch(operand, case, case_function_list)

Simulate

>>> print(multi_measurement([case, operand]))
{(0, 2): 0.25, (1, 3): 0.25, (2, 1): 0.25, (3, 1): 0.125, (3, 3): 0.125}