rudiments | A drum machine written in Rust | Audio Utils library

Appears that the grammar is a direct implementation of an EBNF representation of the desired DSL. A bit more work is required to get it to work well in ANTLR. As is:

1) there is a mutual left recursion problem with the rules function_expr, paramList, and param;

2) sentence can match nothing;

3) WS is hidden in the lexer, so sentence could never match, anyway ;);

4) the ID rule shadows WORD, so WORD tokens will never be emitted.

(You should have received a Tool warning on 1 and 2; never ignore, since warnings indicate that run-time behavior can be affected.)

The basic form for an expression rule is to list, in a single rule, all of the alternate forms of the expression.