You take Claude, you create a new Project, in your Project you explain the context of what you are doing and what you are programming (you have to explain it only once!).
If you have specific technical documentation (e.g. rare programming language, your own framework, etc), you can put it there in the project.
Then you create a conversation, and copy-paste the source-code for your file, and ask for your refactoring or improvement.
You take Claude, you create a new Project, in your Project you explain the context of what you are doing and what you are programming (you have to explain it only once!).
If you have specific technical documentation (e.g. rare programming language, your own framework, etc), you can put it there in the project.
Then you create a conversation, and copy-paste the source-code for your file, and ask for your refactoring or improvement.
If you are lazy just say: "give me the full code"
and then
"continue the code" few times in a row
and you're done :)