Merge pull request #21393 from folke/highlight_show

feat(lsp): add function to get semantic tokens at cursor
feat: `vim.inspect_pos()`, `vim.show_pos()` and `:Inspect[!]`

4 files changed, 287 insertions, 1 deletions

diff --git a/runtime/lua/vim/_init_packages.lua b/runtime/lua/vim/_init_packages.lua
index 19c8608732..0c4ee8636d 100644
--- a/runtime/lua/vim/_init_packages.lua
+++ b/runtime/lua/vim/_init_packages.lua
@@ -56,6 +56,9 @@ setmetatable(vim, {
     if vim._submodules[key] then
       t[key] = require('vim.' .. key)
       return t[key]
+    elseif key == 'inspect_pos' or key == 'show_pos' then
+      require('vim._inspector')
+      return t[key]
     elseif vim.startswith(key, 'uri_') then
       local val = require('vim.uri')[key]
       if val ~= nil then
diff --git a/runtime/lua/vim/_inspector.lua b/runtime/lua/vim/_inspector.lua
new file mode 100644
index 0000000000..f46a525910
--- /dev/null
+++ b/runtime/lua/vim/_inspector.lua
@@ -0,0 +1,238 @@
+---@class InspectorFilter
+---@field syntax boolean include syntax based highlight groups (defaults to true)
+---@field treesitter boolean include treesitter based highlight groups (defaults to true)
+---@field extmarks boolean|"all" include extmarks. When `all`, then extmarks without a `hl_group` will also be included (defaults to true)
+---@field semantic_tokens boolean include semantic tokens (defaults to true)
+local defaults = {
+  syntax = true,
+  treesitter = true,
+  extmarks = true,
+  semantic_tokens = true,
+}
+
+---Get all the items at a given buffer position.
+---
+---Can also be pretty-printed with `:Inspect!`. *:Inspect!*
+---
+---@param bufnr? number defaults to the current buffer
+---@param row? number row to inspect, 0-based. Defaults to the row of the current cursor
+---@param col? number col to inspect, 0-based. Defaults to the col of the current cursor
+---@param filter? InspectorFilter (table|nil) a table with key-value pairs to filter the items
+---               - syntax (boolean): include syntax based highlight groups (defaults to true)
+---               - treesitter (boolean): include treesitter based highlight groups (defaults to true)
+---               - extmarks (boolean|"all"): include extmarks. When `all`, then extmarks without a `hl_group` will also be included (defaults to true)
+---               - semantic_tokens (boolean): include semantic tokens (defaults to true)
+---@return {treesitter:table,syntax:table,extmarks:table,semantic_tokens:table,buffer:number,col:number,row:number} (table) a table with the following key-value pairs. Items are in "traversal order":
+---               - treesitter: a list of treesitter captures
+---               - syntax: a list of syntax groups
+---               - semantic_tokens: a list of semantic tokens
+---               - extmarks: a list of extmarks
+---               - buffer: the buffer used to get the items
+---               - row: the row used to get the items
+---               - col: the col used to get the items
+function vim.inspect_pos(bufnr, row, col, filter)
+  filter = vim.tbl_deep_extend('force', defaults, filter or {})
+
+  bufnr = bufnr or 0
+  if row == nil or col == nil then
+    -- get the row/col from the first window displaying the buffer
+    local win = bufnr == 0 and vim.api.nvim_get_current_win() or vim.fn.bufwinid(bufnr)
+    if win == -1 then
+      error('row/col is required for buffers not visible in a window')
+    end
+    local cursor = vim.api.nvim_win_get_cursor(win)
+    row, col = cursor[1] - 1, cursor[2]
+  end
+  bufnr = bufnr == 0 and vim.api.nvim_get_current_buf() or bufnr
+
+  local results = {
+    treesitter = {},
+    syntax = {},
+    extmarks = {},
+    semantic_tokens = {},
+    buffer = bufnr,
+    row = row,
+    col = col,
+  }
+
+  -- resolve hl links
+  ---@private
+  local function resolve_hl(data)
+    if data.hl_group then
+      local hlid = vim.api.nvim_get_hl_id_by_name(data.hl_group)
+      local name = vim.fn.synIDattr(vim.fn.synIDtrans(hlid), 'name')
+      data.hl_group_link = name
+    end
+    return data
+  end
+
+  -- treesitter
+  if filter.treesitter then
+    for _, capture in pairs(vim.treesitter.get_captures_at_pos(bufnr, row, col)) do
+      capture.hl_group = '@' .. capture.capture
+      table.insert(results.treesitter, resolve_hl(capture))
+    end
+  end
+
+  -- syntax
+  if filter.syntax then
+    for _, i1 in ipairs(vim.fn.synstack(row + 1, col + 1)) do
+      table.insert(results.syntax, resolve_hl({ hl_group = vim.fn.synIDattr(i1, 'name') }))
+    end
+  end
+
+  -- semantic tokens
+  if filter.semantic_tokens then
+    for _, token in ipairs(vim.lsp.semantic_tokens.get_at_pos(bufnr, row, col) or {}) do
+      token.hl_groups = {
+        type = resolve_hl({ hl_group = '@' .. token.type }),
+        modifiers = vim.tbl_map(function(modifier)
+          return resolve_hl({ hl_group = '@' .. modifier })
+        end, token.modifiers or {}),
+      }
+      table.insert(results.semantic_tokens, token)
+    end
+  end
+
+  -- extmarks
+  if filter.extmarks then
+    for ns, nsid in pairs(vim.api.nvim_get_namespaces()) do
+      if ns:find('vim_lsp_semantic_tokens') ~= 1 then
+        local extmarks = vim.api.nvim_buf_get_extmarks(bufnr, nsid, 0, -1, { details = true })
+        for _, extmark in ipairs(extmarks) do
+          extmark = {
+            ns_id = nsid,
+            ns = ns,
+            id = extmark[1],
+            row = extmark[2],
+            col = extmark[3],
+            opts = resolve_hl(extmark[4]),
+          }
+          local end_row = extmark.opts.end_row or extmark.row -- inclusive
+          local end_col = extmark.opts.end_col or (extmark.col + 1) -- exclusive
+          if
+            (filter.extmarks == 'all' or extmark.opts.hl_group) -- filter hl_group
+            and (row >= extmark.row and row <= end_row) -- within the rows of the extmark
+            and (row > extmark.row or col >= extmark.col) -- either not the first row, or in range of the col
+            and (row < end_row or col < end_col) -- either not in the last row or in range of the col
+          then
+            table.insert(results.extmarks, extmark)
+          end
+        end
+      end
+    end
+  end
+  return results
+end
+
+---Show all the items at a given buffer position.
+---
+---Can also be shown with `:Inspect`. *:Inspect*
+---
+---@param bufnr? number defaults to the current buffer
+---@param row? number row to inspect, 0-based. Defaults to the row of the current cursor
+---@param col? number col to inspect, 0-based. Defaults to the col of the current cursor
+---@param filter? InspectorFilter (table|nil) see |vim.inspect_pos()|
+function vim.show_pos(bufnr, row, col, filter)
+  local items = vim.inspect_pos(bufnr, row, col, filter)
+
+  local lines = { {} }
+
+  ---@private
+  local function append(str, hl)
+    table.insert(lines[#lines], { str, hl })
+  end
+
+  ---@private
+  local function nl()
+    table.insert(lines, {})
+  end
+
+  ---@private
+  local function item(data, comment)
+    append('  - ')
+    append(data.hl_group, data.hl_group)
+    append(' ')
+    if data.hl_group ~= data.hl_group_link then
+      append('links to ', 'MoreMsg')
+      append(data.hl_group_link, data.hl_group_link)
+      append(' ')
+    end
+    if comment then
+      append(comment, 'Comment')
+    end
+    nl()
+  end
+
+  -- treesitter
+  if #items.treesitter > 0 then
+    append('Treesitter', 'Title')
+    nl()
+    for _, capture in ipairs(items.treesitter) do
+      item(capture, capture.lang)
+    end
+    nl()
+  end
+
+  if #items.semantic_tokens > 0 then
+    append('Semantic Tokens', 'Title')
+    nl()
+    for _, token in ipairs(items.semantic_tokens) do
+      local client = vim.lsp.get_client_by_id(token.client_id)
+      client = client and (' (' .. client.name .. ')') or ''
+      item(token.hl_groups.type, 'type' .. client)
+      for _, modifier in ipairs(token.hl_groups.modifiers) do
+        item(modifier, 'modifier' .. client)
+      end
+    end
+    nl()
+  end
+
+  -- syntax
+  if #items.syntax > 0 then
+    append('Syntax', 'Title')
+    nl()
+    for _, syn in ipairs(items.syntax) do
+      item(syn)
+    end
+    nl()
+  end
+  -- extmarks
+  if #items.extmarks > 0 then
+    append('Extmarks', 'Title')
+    nl()
+    for _, extmark in ipairs(items.extmarks) do
+      if extmark.opts.hl_group then
+        item(extmark.opts, extmark.ns)
+      else
+        append('  - ')
+        append(extmark.ns, 'Comment')
+        nl()
+      end
+    end
+    nl()
+  end
+
+  if #lines[#lines] == 0 then
+    table.remove(lines)
+  end
+
+  local chunks = {}
+  for _, line in ipairs(lines) do
+    vim.list_extend(chunks, line)
+    table.insert(chunks, { '\n' })
+  end
+  if #chunks == 0 then
+    chunks = {
+      {
+        'No items found at position '
+          .. items.row
+          .. ','
+          .. items.col
+          .. ' in buffer '
+          .. items.buffer,
+      },
+    }
+  end
+  vim.api.nvim_echo(chunks, false, {})
+end
diff --git a/runtime/lua/vim/lsp/semantic_tokens.lua b/runtime/lua/vim/lsp/semantic_tokens.lua
index b7ffedab2b..e14d3e51cd 100644
--- a/runtime/lua/vim/lsp/semantic_tokens.lua
+++ b/runtime/lua/vim/lsp/semantic_tokens.lua
@@ -585,6 +585,51 @@ function M.stop(bufnr, client_id)
   end
 end
 
+--- Return the semantic token(s) at the given position.
+--- If called without arguments, returns the token under the cursor.
+---
+---@param bufnr number|nil Buffer number (0 for current buffer, default)
+---@param row number|nil Position row (default cursor position)
+---@param col number|nil Position column (default cursor position)
+---
+---@return table|nil (table|nil) List of tokens at position
+function M.get_at_pos(bufnr, row, col)
+  if bufnr == nil or bufnr == 0 then
+    bufnr = api.nvim_get_current_buf()
+  end
+
+  local highlighter = STHighlighter.active[bufnr]
+  if not highlighter then
+    return
+  end
+
+  if row == nil or col == nil then
+    local cursor = api.nvim_win_get_cursor(0)
+    row, col = cursor[1] - 1, cursor[2]
+  end
+
+  local tokens = {}
+  for client_id, client in pairs(highlighter.client_state) do
+    local highlights = client.current_result.highlights
+    if highlights then
+      local idx = binary_search(highlights, row)
+      for i = idx, #highlights do
+        local token = highlights[i]
+
+        if token.line > row then
+          break
+        end
+
+        if token.start_col <= col and token.end_col > col then
+          token.client_id = client_id
+          tokens[#tokens + 1] = token
+        end
+      end
+    end
+  end
+  return tokens
+end
+
 --- Force a refresh of all semantic tokens
 ---
 --- Only has an effect if the buffer is currently active for semantic token
diff --git a/runtime/lua/vim/treesitter.lua b/runtime/lua/vim/treesitter.lua
index 25f0e7dc5e..582922ecb6 100644
--- a/runtime/lua/vim/treesitter.lua
+++ b/runtime/lua/vim/treesitter.lua
@@ -240,7 +240,7 @@ function M.get_captures_at_pos(bufnr, row, col)
       if M.is_in_node_range(node, row, col) then
         local c = q._query.captures[capture] -- name of the capture in the query
         if c ~= nil then
-          table.insert(matches, { capture = c, metadata = metadata })
+          table.insert(matches, { capture = c, metadata = metadata, lang = tree:lang() })
         end
       end
     end