Address #9: Add a telescope extension

README.md

@@ -228,6 +228,19 @@ Key       | Command
 `zR`      | Expand all nodes in the tree
 `zx`/`zX` | Sync code folding to the tree (useful if they get out of sync)
 
+## Fuzzy Finding
+
+There is a telescope extension for fuzzy finding and jumping to symbols. It
+functions similarly to the builtin `lsp_document_symbols` picker, the main
+difference being that the aerial only includes the types of symbols in the
+`filter_kind` configuration option. Load the extension with:
+
+```lua
+require('telescope').load_extension('aerial')
+```
+
+You can then begin fuzzy finding with `:Telescope aerial`
+
 ## Highlight
 
 There are highlight groups created for each `SymbolKind`. There will be one for

lua/telescope/_extensions/aerial.lua

@@ -0,0 +1,77 @@
+local backend = require("aerial.backend")
+local config = require("aerial.config")
+local data = require("aerial.data")
+
+local conf = require("telescope.config").values
+local entry_display = require("telescope.pickers.entry_display")
+local finders = require("telescope.finders")
+local pickers = require("telescope.pickers")
+local telescope = require("telescope")
+
+local function aerial_picker(opts)
+  opts = opts or {}
+  local bufnr = vim.api.nvim_get_current_buf()
+  local filename = vim.api.nvim_buf_get_name(0)
+
+  if not backend.is_supported() then
+    backend.log_support_err()
+    return
+  elseif not data:has_symbols(0) then
+    backend.fetch_symbols_sync(opts.timeout)
+  end
+
+  local displayer = entry_display.create({
+    separator = " ",
+    items = {
+      { width = 4 },
+      { width = 30 },
+      { remaining = true },
+    },
+  })
+
+  local function make_display(entry)
+    local item = entry.value
+    local icon = config.get_icon(item.kind)
+    local text = vim.api.nvim_buf_get_lines(bufnr, item.lnum - 1, item.lnum, false)[1] or ""
+    text = vim.trim(text)
+    local columns = {
+      { icon, "Aerial" .. item.kind .. "Icon" },
+      { item.name, "Aerial" .. item.kind },
+      text,
+    }
+    return displayer(columns)
+  end
+
+  local function make_entry(item)
+    return {
+      value = item,
+      display = make_display,
+      ordinal = item.name .. " " .. string.lower(item.kind),
+      lnum = item.lnum,
+      col = item.col + 1,
+      filename = filename,
+    }
+  end
+
+  local results = {}
+  if data:has_symbols(0) then
+    data[0]:visit(function(item)
+      table.insert(results, item)
+    end)
+  end
+  pickers.new(opts, {
+    prompt_title = "Document Symbols",
+    finder = finders.new_table({
+      results = results,
+      entry_maker = make_entry,
+    }),
+    sorter = conf.generic_sorter(opts),
+    previewer = conf.qflist_previewer(opts),
+  }):find()
+end
+
+return telescope.register_extension({
+  exports = {
+    aerial = aerial_picker,
+  },
+})