Re: [RFC] Default expression

> Special-casing the T_DEFAULT grammar would not only bloat the grammar rules but also increase > the chance that new expression grammars introduced in future, which could conveniently interoperate > with default, would be unintentionally excluded by omission. Forgot to add that I don't think the fact doing this properly requires a more complex grammar is a strong argument for doing it "the easy way" of allowing all expressions. It's a special case, and that should be reflected in the grammar.