There are simpler and less intrusive ways to solve outside-AST issues (like an automatic reformatting pass before each build or each diff)<p>What you&#x27;re suggesting raises a bunch of new (non-trivial) issues:<p>- What would you do with code comments? Things like &quot;f(&#x2F;+old_value+&#x2F;new_value)&quot;.<p>- How to store code before preprocessing (C and C++) ?<p>- How to store files mixing several languages (PHP, HTML, Javascript) ?<p>- How do you store code for a DSL?