Thanks. Yes, DTL's core textual syntax is described with PEG. I make use of the Peggy (https://peggyjs.org/) PEG processor to build up the AST that is used to actually process DTL.

There are C based PEG processors, which I've looked at once or twice also, but I haven't sat down to try to convert it. Mostly out of a desire to get the existing module to work well. A working module for one language is better than a partially working module for multiple. :P