feat(lsp): preserve cursor position for move_item command

[MunifTanjim]

Port simrat39/rust-tools.nvim#386

pub struct Allergies(u32);

macro_rules! enum_iter {
    ($name: ident { $($variant: ident),* } ) => {
        #[derive(Debug, PartialEq, Eq, Clone)]
        pub enum $name {
            $( $variant, )*
        }

        impl $name {
            fn variants() -> Vec<$name> {
                vec![$( $name::$variant, )*]
            }
        }
    };
}

enum_iter!(Allergen {
    Eggs,
    Peanuts,
    Shellfish,
    Strawberries,
    Tomatoes,
    Chocolate,
    Pollen,
    Cats
});

impl Allergies {
    pub fn new(score: u32) -> Self {
        Allergies(score)
    }

    pub fn is_allergic_to(&self, allergen: &Allergen) -> bool {
        (self.0 & 1_u32 << allergen.clone() as u32) != 0
    }

    pub fn allergies(&self) -> Vec<Allergen> {
        Allergen::variants()
            .iter()
            .filter_map(|allergen| self.is_allergic_to(allergen).then_some(allergen.clone()))
            .collect()
    }
}

[github-actions]

Review Checklist

Does this PR follow the Contribution Guidelines? Following is a partial checklist:

Proper conventional commit scoping:

• For example, fix(lsp): some lsp-related bugfix

• Pull request title has the appropriate conventional commit prefix.

If applicable:

• Tested
  • Tests have been added.
  • Tested manually (Steps to reproduce in PR description).
• Updated documentation.

[mrcjkb]

Thanks 🙏

[mrcjkb]

question: This function does more than just extracting the cursor position, as it also implements the snippet_text_edits_to_text_edits logic.
Can it be reduced to just the single functionality of extracting the cursor position?

Correct me if I'm wrong; I don't think we'll see any meaningful performance gains by looping over the text edits once.

On a related note: I'm wondering if we even need to apply snippet_text_edits_to_text_edits here.
It seems unlikely to me that moving an item would result in a snippet text edit. What do you think?

[MunifTanjim]

question: This function does more than just extracting the cursor position, as it also implements the snippet_text_edits_to_text_edits logic.
Can it be reduced to just the single functionality of extracting the cursor position?

Yes, sorry about that. I just copy-pasted my old PR. Updated now.

On a related note: I'm wondering if we even need to apply snippet_text_edits_to_text_edits here.
It seems unlikely to me that moving an item would result in a snippet text edit. What do you think?

rust-analyzer sends that snippet text edit, nothing we can do here but to patch it for vim.lsp.util.apply_text_edits.