This macro is not implemented in Asciidoctor core because it's a significant attack vector (i.e., security hole). It's one of the key reasons AsciiDoc Python got thrown out of GitHub, so, understandably, it was left out of the original requirements for Asciidoctor.
Of course, there are ways to use it responsibly and it can be useful. I see this as a perfect use case for an extension. In fact, it's a very straightforward block extension to implement. The implementation would look reasonably similar to the textql block macro extension:
or the tree block macro extension:
If you're willing to take a shot at it, I would be glad to merge it into the asciidoctor-extensions-lab. We'll eventually pull some of those extensions out into gems, either as a dedicated gem or a gem containing a group of related extensions.
Locked
