Neovim-Context

context.lua

local function binary_search(tbl, line)
  local left = 1
  local right = #tbl
  local mid = 0

  while true do
    mid = bit.rshift(left + right, 1)
    if not tbl[mid] then
      return
    end

    local range = tbl[mid].range or tbl[mid].location.range
    if not range then
      return
    end

    if line >= range.start.line and line <= range["end"].line then
      return mid
    elseif line < range.start.line then
      right = mid - 1
    else
      left = mid + 1
    end
    if left > right then
      return
    end
  end
end

vim.keymap.set("n", "<C-g>", function()
  local params = { textDocument = vim.lsp.util.make_text_document_params() }

  vim.lsp.buf_request(0, "textDocument/documentSymbol", params, function(err, result, ctx)
    if err or not result or not vim.api.nvim_buf_is_loaded(ctx.bufnr) then
      return
    end

    local lnum = vim.api.nvim_win_get_cursor(0)[1] - 1
    local mid = binary_search(result, lnum)

    if not mid then
      return
    end

    local function filter(tbl)
      local filtered = {}
      if tbl.children == nil or vim.tbl_isempty(tbl.children) then
        return {}
      end
      for _, s in ipairs(tbl.children) do
        if
          (s.range["start"].line <= lnum and s.range["end"].line >= lnum)
          and (
            s.kind == vim.lsp.protocol.SymbolKind.Function
            or s.kind == vim.lsp.protocol.SymbolKind.Method
            or s.kind == vim.lsp.protocol.SymbolKind.Class
            or s.kind == vim.lsp.protocol.SymbolKind.Namespace
            or s.kind == vim.lsp.protocol.SymbolKind.Constructor
          )
        then
          table.insert(filtered, s)
        end

        if s.children and not vim.tbl_isempty(s.children) then
          s.children = filter(s)
        end
      end
      return filtered
    end

    result[mid].children = filter(result[mid])

    local symbols = vim.tbl_filter(function(t)
      return t.kind == "Function"
        or t.kind == "Method"
        or t.kind == "Class"
        or t.kind == "Namespace"
        or t.kind == "Constructor"
    end, vim.lsp.util.symbols_to_items({ result[mid] }, 0, vim.lsp.get_clients({ bufnr = 0 })[1].offset_encoding))

    local symbol_name = vim.tbl_map(function(t)
      local kind = t.text:match("%[(%w+)%]%s*")
      return t.text:gsub("%[" .. kind .. "%]%s*", "%%#@" .. kind:lower() .. "#")
    end, symbols)

    local sep_list = {
      cpp = "::",
      c = "::",
    }

    vim.o.statusline = (" %%=(%s%%##)%%= "):format(
      table.concat(symbol_name, "%#Conceal#" .. (sep_list[vim.o.ft] or "->"))
    )
  end)
end, { desc = "Show Context" })