Address #9: Add fzf integration

README.md

@@ -230,7 +230,10 @@ Key       | Command
 
 ## Fuzzy Finding
 
-There is a telescope extension for fuzzy finding and jumping to symbols. It
+### Telescope
+
+If you have [telescope](https://github.com/nvim-telescope/telescope.nvim)
+installed, there is an 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:
@@ -241,6 +244,14 @@ require('telescope').load_extension('aerial')
 
 You can then begin fuzzy finding with `:Telescope aerial`
 
+### fzf
+
+If you have [fzf](https://github.com/junegunn/fzf.vim) installed you can trigger
+fuzzy finding with `:call aerial#fzf()`. To create a mapping:
+```vim
+nmap <silent> <leader>ds <cmd>call aerial#fzf()<cr>
+```
+
 ## Highlight
 
 There are highlight groups created for each `SymbolKind`. There will be one for

autoload/aerial.vim

@@ -1,4 +1,24 @@
-
 function! aerial#foldexpr() abort
 	return luaeval('require"aerial.fold".foldexpr(_A)', v:lnum)
 endfunction
+
+function! aerial#fzf() abort
+	let l:labels = luaeval("require('aerial.fzf').get_labels()")
+	if type(l:labels) == type(v:null) && l:labels == v:null
+		return
+	endif
+	call fzf#run({
+				\ 'source': l:labels,
+				\ 'sink': funcref('aerial#goto_symbol'),
+				\ 'options': '--prompt="Document symbols: "',
+				\ 'window': {'width': 0.5, 'height': 0.4},
+				\ })
+endfunction
+
+function! aerial#goto_symbol(symbol) abort
+	call luaeval("require('aerial.fzf').goto_symbol(_A)", a:symbol)
+endfunction
+
+function! s:mk_fzf_callback(callback)
+  return { item -> s:fzf_leave(a:callback, s:ChooserValueFromLabel(item)) }
+endfunction

lua/aerial/fzf.lua

@@ -0,0 +1,40 @@
+local backend = require("aerial.backend")
+local data = require("aerial.data")
+local navigation = require("aerial.navigation")
+local M = {}
+
+M.get_labels = function(opts)
+  opts = opts or {}
+  if not backend.is_supported() then
+    backend.log_support_err()
+    return nil
+  elseif not data:has_symbols(0) then
+    backend.fetch_symbols_sync(opts.timeout)
+  end
+  local results = {}
+  if data:has_symbols(0) then
+    data[0]:visit(function(item)
+      local label = string.format("%d:%s", item.lnum, item.name)
+      table.insert(results, label)
+    end)
+  end
+  return results
+end
+
+M.goto_symbol = function(symbol)
+  local colon = string.find(symbol, ":")
+  local lnum = tonumber(string.sub(symbol, 1, colon - 1))
+  local name = string.sub(symbol, colon + 1)
+  local idx = 1
+  data[0]:visit(function(item)
+    if lnum == item.lnum and name == item.name then
+      navigation.select({
+        index = idx,
+      })
+      return true
+    end
+    idx = idx + 1
+  end)
+end
+
+return M