title: Spacing around parentheses in Ruby
body: <p>I've recently had some problems getting a path working properly.  The solution turned out to be simple but I had an unexpected problem that stopped me getting to it.  The following line, included in an erb template, works perfectly:</p>
  
  <pre><code>&lt;%= button_to "Confirm delivery", delivery_confirm_path( @delivery ) %&gt;
  </code></pre>
  
  <p>This one doesn't:</p>
  
  <pre><code>&lt;%= button_to "Confirm delivery", delivery_confirm_path ( @delivery ) %&gt;
  </code></pre>
  
  <p>It seems spacing before the opening parenthesis is not allowed in this case.  The error I get is this:</p>
  
  <pre><code>/app/views/deliveries/_delivery_buttons.html.erb:22: syntax error,
  unexpected tLPAREN_ARG, expecting keyword_do or '{' or '('
  ...ivery", delivery_confirm_path ( @delivery ) );@output_buffer...
  ...                               ^
  </code></pre>
  
  <p>Can anybody explain why this causes an error?</p>
  
  <p>EDIT: for info, this is Ruby 1.9.2 and Rails 3.0.9, on Windows 7 64-bit</p>