External: https://core.tcl-lang.org/akupries/marpa/home
See also
Marpa is a Tcl binding to libmarpa, in the spirit of the Marpa::R2 perl binding.
libmarpa is an Earley parser engine, with both Leo and Aycock-Horspool fixes.
Official example parsers/languages (in the languages/ directory of the sources):
Examples in work branches