Randal L. Schwartz wrote
Casey> OMeta is ridiculously cool. You can do source to source
Casey> translation in some cases, for example, without a pretty printer
Casey> by running your grammar transformations through backward. I'm not
Casey> aware of any other system that let's you do that.
Except maybe XTreams PEG. :)
Are there any examples of that, by chance?
If you look in the docs  you’ll start to look for subclasses of XTActor/PEG.Actor such as PEG.WikiGenerator. They are not present in Squeak or Pharo because Nicolas Cellier did not port them over. I think it was because they were plugged into other packages such as XML.Element, So the answer to your question is no. The way to find classes like WikiGenerator is to install Cincom’s VisualWorks (on a Mac for example) and include the Streams-Parsing-Tests package. Then adapt to Squeak/Pharo.
Chapter 3, p. 100, footnote 9 of “Squeak Personal Computing and Multimedia” mentions a “Squeak demo for blowing students minds.” That’s a label Mark used for presenting the contents of a lecture he gave to students. It’s reasonable to assume that whatever was the balance of that presentation is material you’ve already been exposed to by reading Mark’s book. However, if you order the book from amazon.coom, it comes with a rich CD-ROM assembled by Stephen T. Pope with content I would expect would blow your mind.