Frequently asked questions (FAQs)

This section answers some questions that might come to your mind.

Where can I learn more about railway-oriented programming?

Scott Wlaschin's blog post Railway oriented programming comes with lots of examples and illustrations as well as videos and slides from his talks.

Should I replace all raised exceptions with trcks.Result?

No, you should not. Scott Wlaschin's blog post Against Railway-Oriented Programming lists eight scenarios where raising or not catching an exception is the better choice.

Which static type checkers does trcks support?

trcks is compatible with current versions of mypy and pyright. Other type checkers may work as well.

Which alternatives to trcks are there?

returns supports object-oriented style and functional style (like trcks). It provides the returns.result.Result container (and multiple other containers) for synchronous code and the returns.future.Future and the returns.future.FutureResult container for asynchronous code. Whereas the returns.result.Result container is pretty similar to trcks.Result, the returns.future.Future container and the returns.future.FutureResult container deviate from collections.abc.Awaitable and trcks.AwaitableResult. Other major differences are:

• returns provides do notation and dependency injection.
• The authors of returns recommend using mypy along with their suggested mypy configuration and their custom mypy plugin.

Expression supports object-oriented style ("fluent syntax") and functional style (like trcks). It provides the expression.core.result.Result class (and multiple other container classes) for synchronous code. The expression.core.result.Result class is pretty similar to trcks.Result and trcks.oop.ResultWrapper. An AsyncResult type based on collections.abc.AsyncGenerator will be added in a future version.

Which libraries have inspired trcks?

trcks is mostly inspired by the Python libraries mentioned in the previous section and by the TypeScript library fp-ts.

Where can I find examples for using trcks?

The repository trcks-example-cyclopts contains an example CLI application that uses trcks along with cyclopts.

The repository trcks-example-fastapi contains an example backend application that uses trcks along with FastAPI.