refactor: rewrite to use mappings (for most modes)

[Sam-programs]

Operator-pending mode still doesn't work, because i am not sure how it's supposed to work.
I added comments starting with WIP: for things that still need discussion.
Fix: #58
Fix: #46
Fix: #49

[max397574]

I'm also currently rewriting this on a branch here in the repo
I don't currently have time to work on it nor to review this pr properly
so for now I wouldn't spend too much time working on this because perhaps I'll rather use my implementation

[max397574]

@Sam-programs I added some changes to this pr
would it be okay to merge this from your side?

[Sam-programs]

@Sam-programs I added some changes to this pr
would it be okay to merge this from your side?

Your changes LGTM.

In the commit above, I swapped expr-mappings to feedkeys calls to allow functions to change the buffer because functions needed to vim.schedule code that modifies the buffer. e.g:

        vim.schedule(function()
            vim.api.nvim_set_current_line("")
        end

EDIT:
This might also remove the need for the defer here. I can't check because I don't use luasnip

            -- Defer execution to avoid side-effects
            vim.defer_fn(function()
                -- set undo point
                vim.o.ul = vim.o.ul
                require("luasnip").expand_or_jump()
            end, 1)

[max397574]

the defer is still needed
didn't test the other case but sounds good 👍
thank you very much for the contribution

I'll merge this in the next few days

[max397574]

closes #23