Is your feature request related to a use case or problem?
A number of other projects are switching from mypy to Pyrefly for type checking Python code. We should do the same for Quantumlib projects if possible. Pyrefly is much faster than mypy and has better IDE support.
What solution or approach do you envision?
- Use Pyrefly's facility for creating a configuration based on an existing mypy configuration (using Cirq's current mypy configuration).
- (Added 2026-07-22): make it ignore Jupyter notebook files
- Run Pyrefly to find and fix whatever problems it flags (or adjust the config to ignore certain ones deemed low-priority for now)
- Add a
check/typecheck script (initially a copy of check/mypy) to replace check/mypy. Deprecate check/mypy so developers have an opportunity to switch.
- Replace the type check in CI with a Pyrefly-based one
How urgent is this for you?
P2 – needed within two quarters
Is your feature request related to a use case or problem?
A number of other projects are switching from mypy to Pyrefly for type checking Python code. We should do the same for Quantumlib projects if possible. Pyrefly is much faster than mypy and has better IDE support.
What solution or approach do you envision?
check/typecheckscript (initially a copy ofcheck/mypy) to replacecheck/mypy. Deprecatecheck/mypyso developers have an opportunity to switch.How urgent is this for you?
P2 – needed within two quarters