Thanks for the links. As the current de-facto maintainer of PPI, the answer is rather simple: P::T predates PPI by almost two years: https://metacpan.org/sour

Thanks for the links. As the current de-facto maintainer of PPI, the answer is rather simple: P::T predates PPI by almost two years: https://metacpan.org/source/SHANCOCK/Perl-Tidy-20021130/CHANGES#L1685 https://metacpan.org/source/SHANCOCK/Perl-Tidy-20021130/CHAN... https://metacpan.org/source/ADAMK/PPI-0.1/Changes https://metacpan.org/source/ADAMK/PPI-0.1/Changes and: For the longest time Perl was considered unparsable, primarily due to the two features of function parens being optional, and the argument-slurpiness of function calls being unknowable without introspecting the function reference that ends up being the final one, at runtime. In the most famous example this can lead to a / after a function call being considered either the division operator or the start of a regex; with both interpretations resulting in valid Perl code. It took a while for anyone to come up with a schema in which Perl could be parsed while also being round-trippable. It took PPI a while to get there and be stable, and meanwhile P::T had already become stable itself.