syntax_data: {"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // Compute Option<yield_ty>
context_before:             CoroutineKind::Desugared(CoroutineDesugaring::Gen, _) => {
context_after:                 let option_did = tcx.require_lang_item(LangItem::Option, body.span);