title: Lua string.match uses irregular regular expressions?
body: <p>I'm curious why this doesn't work, and need to know why/how to work around it; I'm trying to detect whether some input is a question, I'm pretty sure string.match is what I need, but:</p>
  
  <p><code>print(string.match("how much wood?", "(how|who|what|where|why|when).*\\?"))</code></p>
  
  <p>returns nil. I'm <a href="http://lua-users.org/wiki/StringLibraryTutorial" rel="noreferrer">pretty sure Lua's string.match uses regular expressions</a> to find matches in a string, as I've used wildcards (.) before with success, but maybe I don't understand all the mechanics? Does Lua require special delimiters in its string functions? I've tested my regular expression <a href="http://gskinner.com/RegExr/" rel="noreferrer">here</a>, so if Lua used regular regular expressions, it seems like the above code would return <code>"how much wood?"</code>.</p>
  
  <p>Can any of you tell me what I'm doing wrong, what I mean to do, or point me to a good reference where I can get comprehensive information about how Lua's string manipulation functions utilize regular expressions?</p>