Jonathan Worthing has submitted the following report on his RakuAST grant. Delays in publishing are purely my fault, not Jonathan's.
Jonathan also gave a talk during the first Raku conference [on the topic of RakuAST.](https://conf.raku.org/talk/147) It is a highly recommended watch.
My work on RakuAST and the new RakuAST-based compiler frontend in June
saw a further 40 test files from the Raku test suite start to pass in full.
I added RakuAST nodes and compilation to them for the following language
* Regex back-references
* Named regex captures of the form `$=[bar]`
* Regex sigspace
* Substitutions (both for `s/x/y/` and `s[x] = 'y'` forms)
* Postfix, prefix, and infix hyper ops
I also did a number of other improvements:
* Added support for all regex adverbs to the `m//` and `rx//` AST nodes
(this came before substitutions, which were made to support the applicable
adverbs right away)
* Added compilation of `@$foo` contextualizers (without parentheses)
to the existing RakuAST contextualizer nodes
* Ensured that `//` assertions in regexes find a lexical rule of
that name if it exists before looking for a method
* Added support for default parameter values, both with the runtime
semantics and for introspection
* Fixed various minor bugs in regex compilation
* Reinstated more typed compilation error reporting