Pressing the tab key twice strangeness.

[Glenn Travis <travplays@...>]

I was messing around with this:

> f = function (op, a, b)
>>  if op == 'add' then
>>   return a + b
>>  elseif op == 'sub' then
>>   return a - b
>>  end

And it looked like I needed to press tab in order to follow the ‘formatting”. The first time I pressed tab I got an alert beep and the second time I got a directory listing:

Lua 5.3.4  Copyright (C) 1994-2017 Lua.org, PUC-Rio

> 

.bash_history                               .DS_Store                                   Desktop                                     krbook                                      Pictures                                   

.bash_sessions                              .idm                                        Documents                                   Library                                     Public   

<snip>

If I were on the unix shell in terminal pressing tab ‘asks’ if I want to all eleventy million commands. But why Lua wants to evidently call ls is beyond me. 

Have I missed something or is this something that I will discover as I continue through the book?

Thank you,

Trav