syntax_data: {"ast_node_type":"variable","tokens":[{"end":67,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let (lhs_ty, rhs_ty, lhs, rhs) = self.binop_args();
context_before:             ty::ExprKind::Binop(op) => {
context_after:                 write!(f, "({op:?}: ({:?}: {:?}), ({:?}: {:?}))", lhs, lhs_ty, rhs, rhs_ty,)