Felix is built on an extensible parser which uses EBNF for the productions. The Felix "language" is defined in the library by such productions. The action codes

Felix is built on an extensible parser which uses EBNF for the productions. The Felix "language" is defined in the library by such productions. The action codes of the grammar are arbitrary Scheme functions returning non-arbitrary s-expressions which map to Felix AST nodes. The grammar is here: http://felix-lang.org/lib/grammar http://felix-lang.org/lib/grammar Close examination reveals even the regexps for literals are defined in the grammar. The parser is built on top of the excellent extensible GLR+ parsing tool Dypgen. In principle the Felix parsing system is independent of Felix. All you need to do is replace the s-expression to Felix AST translator with some kind of pretty printer for s-expressions, even XML, and you can target anything.