That&#x27;s true, code is rarely linear. But the whole idea of encapsulation, separation of concerns and many, many other practices is to increase locality of a code. In that sense a well written and structured code has local, mostly linear systems that you can analyze in isolation to get insight into the larger system.<p>With this in mind it doesn&#x27;t matter that the overarching structure is much more complex. Translation unit you&#x27;re analyzing is (or should) be mostly human-parsable in a linear fashion.<p>What I found eye-opening in this article is that it challenged my concept of well structured code file. I was like &quot;what?! this is blasphemy!&quot; from the very beginning but at the end I was like &quot;huh, I finally understand why sometimes #define&#x27;s feel better in the center of a file than they feel at the top&quot;[1]. It&#x27;s rare for a blog entry to stir me like this. :)<p>[1] amongst other things that came though my head