`APOS_STRING_MODE` caused me trouble on [gherkin-syntax-highlighters](https://github.com/cucumber/gherkin-syntax-highlighters) when a step has an apostrophe, like:

    Given I've entered &lt;input_1&gt; into the calculator

Apostrophes are allows in steps, but it totally threw off highlight.js, and highlight.js didn't highlight anything in the `<code>`. I just removed `APOS_STRING_MODE` and haven't seen any negative consequences.