[mini.pick] pick "buffer lines" in current buffer and include treesitter syntax highlighting

[abeldekat]

For the current buffer, I modified the buf_lines picker to show the lines with treesitter syntax highlighting.

The code:

Pick.registry.buffer_lines_current = function()
  local show = function(buf_id, items, query, opts)
    if items and #items > 0 then -- one buffer, one ft: Enable highlighting
      local ft = vim.bo[items[1].bufnr].filetype
      -- vim.bo.filetype = ft -- Safer:
      vim.bo[buf_id].filetype = ft
    end
    Pick.default_show(buf_id, items, query, opts)
  end
  MiniExtra.pickers.buf_lines({ scope = "current" }, { source = { show = show } })
end

I use this quite often to fuzzy search a function while the lsp is starting up.

[echasnovski]

Oh, that's a nice one!

Couple of remarks:

• I think vim.bo.filetype = ft is safer to be vim.bo[buf_id].filetype = ft.
• Unfortunately, this is not universal, as shown lines start with digits and :. I have doubts that every tree-sitter parser handles this well.

[abeldekat]

Thanks! I am having a really good time with mini.pick....)

I think vim.bo.filetype = ft is safer to be vim.bo[buf_id].filetype = ft

I need to use the filetype of the buffer being displayed, so I just use the filetype of the first item's bufnr to activate the highlighting in the picker list. Is there another way? I think vim.bo.filetype refers to the filetype of the buffer of the picker....

Unfortunately, this is not universal, as shown lines start with digits and :. I have doubts that every tree-sitter parser handles this well.

Fingers crossed... I am already quite happy it works for lua. This behavior is the standard in Telescope's current_buffer_fuzzy_find. I also looked at Fzf-Lua: No syntax highlighting in lines and blines.

[echasnovski]

I think vim.bo.filetype = ft is safer to be vim.bo[buf_id].filetype = ft

I need to use the filetype of the buffer being displayed, so I just use the filetype of the first item's bufnr to activate the highlighting in the picker list. Is there another way? I think vim.bo.filetype refers to the filetype of the buffer of the picker....

vim.bo.filetype without index operates on the current buffer. The fact that this works is mostly a coincidence.
The first argument with which source.show() is called is [identifier of target buffer](https://github.com/echasnovski/mini.nvim/blob/334a2d9cfbd86ea08c4d870e39b5ba8bb354d938/doc/mini-pick.txt#L3540 (i.e. the buffer in which items are expected to be shown). So setting filetype in that buffer is done with vim.bo[buf_id].filetype = ft.

However, setting filetype usually has some non-trivial side effects. I'd suggest digging a little bit deeper and set highlighting directly. Take a look at how default preview deals with this.

[abeldekat]

Thanks!

I hope this is more correct:

Pick.registry.buffer_lines_current = function()
  local show = function(buf_id, items, query, opts)
    local buf_target = buf_id
    if items and #items > 0 then
      local buf_src = items[1].bufnr -- all items from the same buffer
      local ft = vim.filetype.match({ buf = buf_src })

      local has_lang, lang = pcall(vim.treesitter.language.get_lang, ft)
      local has_ts, _ = pcall(vim.treesitter.start, buf_target, has_lang and lang or ft)
      if not has_ts and ft then vim.bo[buf_target].syntax = ft end
    end
    Pick.default_show(buf_target, items, query, opts)
  end
  MiniExtra.pickers.buf_lines({ scope = "current" }, { source = { show = show } })
end

[echasnovski]

I mean... The initial iteration was already correct, just less robust and efficient :)
And I still think that local ft = vim.bo[items[1].bufnr].filetype approach should be enough.

[abeldekat]

And I still think that local ft = vim.bo[items[1].bufnr].filetype approach should be enough.

Thanks for the feedback! I also updated my initial code fragment, using the safer approach you suggested.

[pkazmier]

I’m very excited to try this later as it was something that I was going to look into for myself at some point!

[abeldekat]

I think I now have a version where the highlighting is complete.
The idea: Override vim.api.nvim_buf_set_lines, to remove the linenumbers added to the buffer of mini.pick. Then, add the linenumbers as extmarks.

The code:

local Pick = require("mini.pick")
local H = {} -- Helper functions for custom pickers

---@type table<string,function>  event MiniPickStart
H.start_hooks = {}
---@type table<string,function> event MiniPickStop
H.stop_hooks = {}

H.setup_autocommands = function()
  local group = vim.api.nvim_create_augroup("minipick-hooks", { clear = true })
  local function au(pattern, desc, hooks)
    vim.api.nvim_create_autocmd({ "User" }, {
      pattern = pattern,
      group = group,
      desc = desc,
      callback = function(...)
        local opts = MiniPick.get_picker_opts() or {}
        if opts and opts.source then
          local hook = hooks[opts.source.name] or function(...) end
          hook(...)
        end
      end,
    })
  end
  au("MiniPickStart", "Picker start hook for source.name", H.start_hooks)
  au("MiniPickStop", "Picker stop hook for source.name", H.stop_hooks)
end

Pick.registry.buffer_lines_current = function()
  local ns = vim.api.nvim_create_namespace("ak")
  local show = function(buf_id, items, query, opts)
    local find_linenr = function(text)
      local _, _, linenr, _ = string.find(text, "(%d+):(.*)")
      return linenr
    end
    local remove_linenrs = function(replacement)
      return vim.tbl_map(function(item)
        local linenr = find_linenr(item)
        if linenr then item = string.sub(item, #linenr + 2) end
        return item
      end, replacement)
    end
    local add_extmark = function(buffer, idx, text)
      vim.api.nvim_buf_set_extmark(buffer, ns, idx - 1, 0, {
        virt_text = { { text } },
        virt_text_pos = "inline",
        priority = 1000, -- higher than treesitter's
      })
    end
    if not items or #items == 0 then Pick.default_show(buf_id, items, query, opts) end

    local set_lines_orig = vim.api.nvim_buf_set_lines
    ---@diagnostic disable-next-line: duplicate-set-field
    vim.api.nvim_buf_set_lines = function(buffer, start, end_, strict_indexing, replacement)
      set_lines_orig(buffer, start, end_, strict_indexing, remove_linenrs(replacement))
      for idx, _ in ipairs(replacement) do
        local linenr = find_linenr(replacement[idx])
        if linenr then add_extmark(buffer, idx, linenr .. ": ") end
      end
    end
    Pick.default_show(buf_id, items, query, opts)
    vim.api.nvim_buf_set_lines = set_lines_orig -- restore original function
  end

  local name = "Buffer lines (current)"
  local src_buffer_filetype = vim.bo.filetype -- remember ft of buffer to search in
  H.start_hooks[name] = function() vim.bo.filetype = src_buffer_filetype end -- set same ft in picker buffer
  H.stop_hooks[name] = function() vim.api.nvim_buf_clear_namespace(0, ns, 0, -1) end -- clean up
  MiniExtra.pickers.buf_lines({ scope = "current" }, { source = { show = show } })
end

H.setup_autocommands()

[echasnovski]

ps: I watched the mini.git demo yesterday and enjoyed seeing Neo McVim in action.

Link?

https://github.com/echasnovski/mini.nvim/blob/main/readmes/mini-git.md#demo

[pkazmier]

Doh! You can tell I had just woke up as I thought someone had done a demo on YouTube that I hadn’t seen, so I was googling “Neo McVim” and was coming up empty handed! 😀

[abeldekat]

It's somewhat reassuring that google still does not know everything...)

[abeldekat]

I now have doubts about the "extmarks" approach. The results are not correct(too many) when adding a modifier like ' before the query. I compared with the original Pick buf_lines scope='current'.

I assumed that extmarks are not taken into account by the search algorithm. Perhaps it's better to use the first version without extmarks.

[abeldekat]

Somehow, the problem above can be fixed by positioning the linenumbers in the extmark on the right:

    -- ...
    for i, pref in pairs(digit_prefixes) do
      pref = string.sub(pref, 1, -2)
      local extmark_opts = { virt_text = { { pref } }, virt_text_pos = "right_align" }
      vim.api.nvim_buf_set_extmark(buf_id, ns_digit_prefix, i - 1, 0, extmark_opts)
    end
    -- ...