title: vim functions with script scope
body: <p>I had installed <a href="https://github.com/carlhuda/janus" rel="noreferrer">Janus</a> with my MacVim setup. In order to learn about how vim scripts work, I've been reading through the vimrc file that Janus uses, and I don't understand how the author of this is using functions. For example, here's one of the functions in the vimrc:</p>
  
  <pre><code>function s:setupWrapping()
    set wrap
    set wrapmargin=2
    set textwidth=72
  endfunction
  </code></pre>
  
  <p>Now, according to the <a href="http://vimdoc.sourceforge.net/htmldoc/usr_41.html#41.7" rel="noreferrer">Defining a function</a> section of the vim manual, 'Function names must begin with a capital letter.' According to the <a href="http://vimdoc.sourceforge.net/htmldoc/map.html#script-local" rel="noreferrer">Local mappings and functions</a> section of the manual, 'When defining a function in a script, "s:" can be prepended to the name to make it local to the script.' However, there's no mention of being able to begin a function name with a lower case letter when specifying its scope as local to the script.</p>
  
  <p>So, is the function as written syntactically incorrect but works anyway, or is it syntactically correct but I can't find the documentation that says so?</p>