add a cool lua repl

lib/lua-repl/repl/plugins/filename_completion.lua

@@ -0,0 +1,63 @@
+local utils = require 'repl.utils'
+local lfs = require 'lfs'
+
+repl:requirefeature 'completion'
+
+local function guess_directory_separator(file_name)
+  return file_name:match('/') or
+         file_name:match('\\') or
+         '/'
+end
+
+local function split_parent_directory(file_name)
+  local parent_directory, directory_entry =
+    file_name:match('^(.+)[\\/](.+)$')
+  if not parent_directory then
+    parent_directory = '.'
+    directory_entry = file_name
+  end
+  return parent_directory, directory_entry
+end
+
+local function is_ignored_directory_entry(entry)
+  return entry == '.' or
+         entry == '..'
+end
+
+local function replace_end_of_string(str, suffix, replacement)
+  assert(str:sub(-#suffix) == suffix)
+  return str:sub(1, -(#suffix+1)) .. replacement
+end
+
+local function complete_file_name(file_name, expr, callback)
+  local directory, partial_entry = split_parent_directory(file_name)
+  for entry in lfs.dir(directory) do
+    if not is_ignored_directory_entry(entry) and
+       entry:find(partial_entry, 1, true) == 1 then
+      callback(replace_end_of_string(expr, partial_entry, entry))
+    end
+  end
+end
+
+local function complete_directory(directory, expr, callback)
+  for entry in lfs.dir(directory) do
+    if not is_ignored_directory_entry(entry) then
+      callback(expr..entry)
+    end
+  end
+end
+
+function after:complete(expr, callback)
+  if utils.ends_in_unfinished_string(expr) then
+    local file_name = expr:match('[%w@/\\.-_+#$%%{}[%]!~ ]+$')
+    if file_name then
+      if file_name:find('[/\\]$') then
+        complete_directory(file_name, expr, callback)
+      else
+        complete_file_name(file_name, expr, callback)
+      end
+    else
+      complete_directory('.', expr, callback)
+    end
+  end
+end