Is it possible to view the source code of one of the Qiskit's algorithm? Actually, I am trying to find how Qiskit implements the HHL algorithm. I want to see the source code for this algorithm.
Qiskit is an open source. Specifically for HHL, see https://github.com/Qiskit/qiskit-aqua/blob/master/qiskit/aqua/algorithms/linear_solvers/hhl.py.
You can also use Qiskit documentation. There is a source code for any of implemented functions and algorithms. In particular for HHL it is available here: https://qiskit.org/documentation/_modules/qiskit/aqua/algorithms/linear_solvers/hhl.html#HHL
When you get to a function/algorithm description it the documentation, simply click on link Code and you will se the source code.