qiskit_qec.linear.symplectic.def _symplectic_product_vv_boolean gives wrong results

[kaiott]

Steps to reproduce the problem

import numpy as np
from qiskit_qec.linear.symplectic import _symplectic_product_vv_boolean

a = np.array([1,0,0,0,1,1,1,0,1,0], dtype=np.bool_)
b = np.array([1,1,1,1,0,0,1,0,1,1], dtype=np.bool_)
_symplectic_product_vv_boolean(a, b, 5)

What is the current behavior?

Returns 1

What is the expected behavior?

The function should return 0, which is the actual symplectic product of the two vectors.
This example is actually the example in the docstring.

Note: Within qiskit_qec this function is never used, as in symplectic_product the input arrays are always converted to dtype numpy.int8.

[drewvandeth]

Thanks @kaiott This is definitely wrong and has a rather simple fix:

r += vec1[i] & vec2[n + i] ^ vec1[n + i] & vec2[i]

should be

r ^= vec1[i] & vec2[n + i] ^ vec1[n + i] & vec2[i]

[drewvandeth]

I will include this fix in a PR that I am pushing through now.
PR #437