Couple questions coming--sharing some experience and hoping to learn something.<p>Do you think the use of parser generators is practical also for performance-critical binary data? For example video streams? (I&#x27;ve never parsed one but I imagine they could be so optimized that it could be impractical to do it with a generic parser generator).<p>What formats are examples of complex structure where parser generators are practical?<p>For my personal needs, I&#x27;ve been getting along very well with plain text relational data. Like<p><pre><code>    numPersons 2
    numAncestors 1
    person john &quot;John Doe&quot;
    person jane &quot;Jane Dane&quot;
    ancestor john jane
</code></pre>
That&#x27;s so trivial that I would never want to depend on a parser generator. Instead I handroll a parser for this format in 10 minutes and 20 lines of C if I don&#x27;t mind bad error messages. And what parser generator would make it easy to check (relational) integrity of above data in a secure way?<p>If I leave away the num* fields above, the parser would need one token of lookahead. What type of grammars are these two versions?