302faba5972/compiler/rustc_ast">the <code>rustc_ast</code> crate</a> for example.</p><p>When all of the supporting tools for a programming language are built together on the same foundation, it leads to a programming <em>environment</em> that feels much more coherent and integrated together. There's one right tool for any given task, which is designed exactly for that task, and every tool ships with the programming language itself (in this case, the <code>oak</code> executable). I think this coherence makes