Retrie: implement high-level refactorings including renaming

[pepeiborra]

High-level refactorings should be doable by combining minimal code generation with retrie commands.

Rename

To rename foo to bar, proceed as follows:

1. Rename foo to bar in place

2. Generate a new declaration:

foo = bar

3. Tell retrie to unfold foo

Move

Similar to rename, but in step 1 we move bar to the target module, while in step 2 we generate foo in the source module.

Extract definition

1. Ask the user for the desired name
2. Generate a new declaration with the desired name, using the selected subexpression as the function body, and the unbound variables as formal parameters
3. Tell retrie to fold the new name

[sureyeaah]

Does LSP support "asking user for a name"?

[Ailrun]

@sureyeaah I think that depends on LSP client, and LSP itself does not specify how to get a name for renaming.

[sureyeaah]

@Ailrun right but does lsp support getting a string from a user, besides via a selection in the text buffer?

Edit: This is in context of extract refactoring (via codeaction)

[Ailrun]

At least LSP-mode (Emacs) supports that. IDK other clients though.

[sureyeaah]

Is there something like that in the LSP spec?

[pepeiborra]

The LSP showMessageRequest supports some interaction with the user. If this is not enough, extract could assign a dummy name and let the user fix it later with a rename refactoring

[wz1000]

IIRC, show message only accepting input from labeled buttons, and doesn't allow accepting arbitrary text.

[Ailrun]

textDocument/rename request accepts arbitrary text, and I think we should support this if we want to add the renaming feature.

[pepeiborra]

For rename I think the editor asks the user

[alanz]

The only way to get a name is the rename command.

So the general workflow required is to say extract a function and give it some assigned name (newFunc3 or something) and then rename it.