Several katas could have better error messaging:

• Superposition : the test harness could log the actual state of the system after prep vs the expected state before asserting that they are the same (the change would add state prep and logging using DumpMachine to AssertEqualOnZeroState)
• BasicGates : a similar improvement, but a bit more extra code to write a unified test wrapper

Here are some examples:

• Root README is missing machine learning category of samples
• README in algorithms is missing repeat-until-success and sudoku-grover
• [README in diagnostics](https://github.com/microsoft/Quantum/blob/main/samples/diagnostics/RE

It would be useful to have a method SummedOp.coeffs analogous to PauliSumOp.coeffs. This would allow the same code to extract coefficients from both via duck typing (eg in PhaseEstimation)

Is your feature request related to a use case or problem? Please describe.

We are noticing lots of cases where we are trying to pull out the gate used in a moment (for instance, if it is a two-qubit layer, to figure

Describe the solution you'd like

A function in cirq.Moment for get_single_gate_from_moment that returns the gate if there is only a single gate or if all gates are the

Did you find a doc bug or broken link that needs to be fixed?

English Qiskit Docs: https://qiskit.org/documentation/release_notes.html#id187
Korean Qiskit Docs: https://qiskit.org/documentation/locale/ko_KR/release_notes.html#id155

We probably might want to generate the version history table in all docs.

To get this codebase up to standard, we need to add type hints. At the very least, perhaps we should start insisting that all new code has type hints added, but moreover we need to add typing to the code that currently exists.

This is a pretty large project, but luckily it can be done incrementally - I believe at this point it's a stretch goal for v1, if anyone wants to help it would be much ap

Describe the bug
When applying resolve_gates() method to QubitCircuit containing the FREDKIN gate, the following error is produced:

ValueError: Gate RY requires one target

To Reproduce

from qutip.qip.circuit import QubitCircuit
A = QubitCircuit(3)
A.add_gate("FREDKIN", targets=[0, 1], controls=[2])
A.resolve_gates()

It might be a good idea to check this

For example, pylint would have caught ProjectQ-Framework/ProjectQ#19 via an undefined variable warning.

It would be nice to allow users to set a custom value for the tensorflow dtype if they are really pushing their simulations (and aware of the memory tradeoffs). This would be a very straightforward feature to add, most likely by adjusting backend_options to accept a dtype argument or something similar

See, e.g., the discussion below:

You could change this line https://github.com/XanaduAI

There seems to be confusion between 'schedule' and 'scheduler' throughout sources and doc. They seem to be used interchangeably, which seems confusing. Is a "schedule" the same as a "scheduleR"?

For example, consider the following code snippet in src/compressor/compressor.lisp:

  (let ((lschedule (make-lscheduler)))
    ;; load up the logical schedule

The variable lschedule and