&gt; How would you represent a tree or graph data structure in text to a human and let them manipulate it?<p>Tree:<p><pre><code>    &#x27;(root (left (left-left left-right)) (right (right-left right-right)))
</code></pre>
Graph:<p><pre><code>    &#x27;(graph (#1=node1 #2=node2) (#2# #3=node3) (#3# #1#))
</code></pre>
Solved problems since at least the early 90s.<p>&gt; Yet using it to paint is a lot harder.<p>Sure, but drawing is only one activity among many possible activities.<p>&gt; As a software developer you&#x27;re often manipulating only text.<p>I think that&#x27;s true for most users: they are reading articles (text); writing comments (text); sending social updates (rich text); watching videos (<i>not</i> text); playing games (<i>not</i> text, but may have textual content, e.g. in-game chat).