Treesitter picker isn't showing markdown headers

[kocv59]

:lua Snacks.picker.treesitter() does not work it says No results found for treesitter but treesitter is enabled for markdown files and the highlighting is working. Do I have to set something? I want to use the treesitter picker to show all markdown headings.

[drowning-cat]

#1997 (reply in thread)

[drowning-cat]

As far as I can tell, Snacks.picker.treesitter is essentially a replacement for lsp_symbols, backed by a treesitter parser, and it's not intended to be used in that way.

[dpetka2001]

It's for Treesitter nodes, which is similar to LSP symbol kinds. You also have to take into account the filter that is taken into account by default.

So, for example with the current configuration of the picker if you invoke it in the file sources.lua above you will get no results. But if you invoke it with :lua Snacks.picker.treesitter({ filter = { lua = true }}) you will see all Treesitter nodes, even those which are filtered out by default.

[drowning-cat]

Sheesh, you're right. However, it does not support filtering of non-standard kinds.

[drowning-cat]

Snacks.picker.treesitter {
  title = 'Headings',
  filter = { markdown = true },
  transform = function(item)
    item.text = vim.split(item.text, '\n')[1]
    item.name = item.text
  end,
}

; after/queries/markdown/locals.scm
[
  (section
    (atx_heading)
    (section)
  )
] @local.scope

(atx_heading (atx_h1_marker)) @local.definition.h1
(atx_heading (atx_h2_marker)) @local.definition.h2
(atx_heading (atx_h3_marker)) @local.definition.h3
(atx_heading (atx_h4_marker)) @local.definition.h4
(atx_heading (atx_h5_marker)) @local.definition.h5
(atx_heading (atx_h6_marker)) @local.definition.h6

[drowning-cat]

Warning

Filtering is only possible using the transform function.

[kocv59]

I put that in a keymapping but it still says No results found for treesitter. Can you show an example of how to use it?

[drowning-cat]

[swarn]

I also wanted this. I think my approach is working all right:

Here's the code:

local get_headings = function(bufnr)
  local ts = vim.treesitter

  local lang = ts.language.get_lang(vim.bo[bufnr].filetype)
  if not lang then return {} end

  local parser = assert(ts.get_parser(bufnr, lang, { error = false }))

  local header_query = [[
    (setext_heading
      heading_content: (_) @h1
      (setext_h1_underline))
    (setext_heading
      heading_content: (_) @h2
      (setext_h2_underline))
    (atx_heading
      (atx_h1_marker)
      heading_content: (_) @h1)
    (atx_heading
      (atx_h2_marker)
      heading_content: (_) @h2)
    (atx_heading
      (atx_h3_marker)
      heading_content: (_) @h3)
    (atx_heading
      (atx_h4_marker)
      heading_content: (_) @h4)
    (atx_heading
      (atx_h5_marker)
      heading_content: (_) @h5)
    (atx_heading
      (atx_h6_marker)
      heading_content: (_) @h6)
  ]]

  local query = ts.query.parse(lang, header_query)
  local root = parser:parse()[1]:root()

  local headings = {}
  for id, node, _, _ in query:iter_captures(root, bufnr) do
    local text = ts.get_node_text(node, bufnr)
    local row, col = node:start()
    table.insert(headings, {
      file = vim.api.nvim_buf_get_name(bufnr),
      pos = { row + 1, col },
      text = text,
      name = text,
      depth = id,
    })
  end

  -- Mark parents and last sibling for snacks tree formatting.
  local parents = {}
  for _, heading in ipairs(headings) do
    local depth = heading.depth
    parents[depth] = heading

    for i = depth - 1, 1, -1 do
      if parents[i] then
        heading.parent = parents[i]
        break
      end
    end

    for i = depth + 1, 6 do
      if parents[i] then
        parents[i].last = true
        parents[i] = nil
      end
    end
  end

  for i = 1, 6 do
    if parents[i] then parents[i].last = true end
  end

  return headings
end

local function format_headings(item, picker)
  local result = {}
  vim.list_extend(result, Snacks.picker.format.tree(item, picker))
  Snacks.picker.highlight.format(item, item.text, result)
  return result
end

And the keymap that uses it

    {
    "gO",
    function()
      Snacks.picker {
        layout = { reverse = false },
        items = get_headings(0),
        format = format_headings,
      }
    end,
    ft = "markdown",
    desc = "Go to Header",
  }

Code borrowed from neovim's own markdown filetype plugin (which gives you the outline in the quickfix menu).

[kocv59]

It's working well, I have two ideas if you have an idea how to implement it: When pressing Enter, it currently goes to the first line of the section. Could you assign a different key to navigate to the last line of the section instead?

Similar to the default picker, if parts of the heading is surrounded by backticks it should be highlighted like in the markdown file.

[swarn]

I updated it; the tree formatting works correctly now, and it highlights the headings like you mentioned.

Navigating to the end of section seems doable. I'd think you might want to change the treesitter query to find sections, rather than headings, so that you have the end of section. My treesitter kung fu is fairly weak, so I'll leave that to someone else.

[dpetka2001]

I'm pretty sure #2124 is invalid. You need a custom local query for Treesitter to recognize the header nodes.

I don't believe it's Snacks' responsibility to provide that. It's the responsibility of the corresponding Treesitter parser.

And if you think the local query should be included, then that sets a precedent for other situations where some user would like to do something that requires a local query as well. Snacks is not supposed to provide local queries. The treesitter picker only requests information from Treesitter itself, which does the parsing according to the queries of each language and returns the results to Snacks and then Snacks just transforms the results into items data structure that is compatible with Snacks pickers.

That is just my personal opinion.

[kocv59]

What is the treesitter picker supposed to do? It can't work without a query?

[dpetka2001]

It works fine for Lua and Python with the predetermined queries that the parsers provide. It's just that the markdown parser does not provide what you want. So, you should be asking for feature to pass custom query to the picker like you said.

[kocv59]

I can make a feature request for nvim-treesitter to provide it in the parser. What does the picker expect the queries to provide?

[dpetka2001]

I'm afraid I'm not qualified to answer this as my treesitter knowledge is very basic. Better wait for Folke's reply in your issue to see what he will say. It will take a while for his reply, since he's away July-September, so he will probably see your issue after October.

Here's the diff of how I incorporated the above solution into my personal config

diff

diff --git a/lua/dpetka2001/util/snacks.lua b/lua/dpetka2001/util/snacks.lua
index 7f9c7bc..f12b45a 100644
--- a/lua/dpetka2001/util/snacks.lua
+++ b/lua/dpetka2001/util/snacks.lua
@@ -198,4 +198,94 @@ function M.snacks_picker()
   }
 end
 
+function M.markdown_treesitter(bufnr)
+  local ts = vim.treesitter
+
+  local lang = ts.language.get_lang(vim.bo[bufnr].filetype)
+  if not lang then
+    return {}
+  end
+
+  local parser = assert(ts.get_parser(bufnr, lang, { error = false }))
+
+  local header_query = [[
+    (setext_heading
+      heading_content: (_) @h1
+      (setext_h1_underline))
+    (setext_heading
+      heading_content: (_) @h2
+      (setext_h2_underline))
+    (atx_heading
+      (atx_h1_marker)
+      heading_content: (_) @h1)
+    (atx_heading
+      (atx_h2_marker)
+      heading_content: (_) @h2)
+    (atx_heading
+      (atx_h3_marker)
+      heading_content: (_) @h3)
+    (atx_heading
+      (atx_h4_marker)
+      heading_content: (_) @h4)
+    (atx_heading
+      (atx_h5_marker)
+      heading_content: (_) @h5)
+    (atx_heading
+      (atx_h6_marker)
+      heading_content: (_) @h6)
+  ]]
+
+  local query = ts.query.parse(lang, header_query)
+  local root = parser:parse()[1]:root()
+
+  local headings = {}
+  for id, node, _, _ in query:iter_captures(root, bufnr) do
+    local text = ts.get_node_text(node, bufnr)
+    local row, col = node:start()
+    table.insert(headings, {
+      file = vim.api.nvim_buf_get_name(bufnr),
+      pos = { row + 1, col },
+      text = text,
+      name = text,
+      depth = id,
+    })
+  end
+
+  -- Mark parents and last sibling for snacks tree formatting.
+  local parents = {}
+  for _, heading in ipairs(headings) do
+    local depth = heading.depth
+    parents[depth] = heading
+
+    for i = depth - 1, 1, -1 do
+      if parents[i] then
+        heading.parent = parents[i]
+        break
+      end
+    end
+
+    for i = depth + 1, 6 do
+      if parents[i] then
+        parents[i].last = true
+        parents[i] = nil
+      end
+    end
+  end
+
+  for i = 1, 6 do
+    if parents[i] then
+      parents[i].last = true
+    end
+  end
+
+  return headings
+end
+
+function M.format_markdown(item, picker)
+  local result = {}
+  vim.list_extend(result, Snacks.picker.format.tree(item, picker))
+  Snacks.picker.highlight.format(item, item.text, result)
+  return result
+end
+
 return M
diff --git a/lua/plugins/snacks.lua b/lua/plugins/snacks.lua
index c78f14a..e0f9d22 100644
--- a/lua/plugins/snacks.lua
+++ b/lua/plugins/snacks.lua
@@ -120,6 +120,20 @@ return {
             end,
           },
           scratch_picker = Util.snacks.scratch_picker(),
+          treesitter = {
+            finder = function(opts, ctx)
+              if vim.bo[ctx.filter.current_buf].filetype == "markdown" then
+                return Util.snacks.markdown_treesitter(ctx.filter.current_buf)
+              end
+              return require("snacks.picker.source.treesitter").symbols(opts, ctx)
+            end,
+            format = function(item, picker)
+              if vim.bo[picker.input.filter.current_buf].filetype == "markdown" then
+                return Util.snacks.format_markdown(item, picker)
+              end
+              return require("snacks.picker.format").lsp_symbol(item, picker)
+            end,
+          },

so that it feels more in the spirit of Snacks configuration and it still retains the original behavior for other filetypes.

[dpetka2001]

Also apologies for my previous reply if it sounded a bit abrupt. I was in a peculiar mood yesterday because of personal reasons and I might have not responded in the most appropriate way towards you.