{"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":".and_then(|pat|"}]}
                        .and_then(|pat| sema.type_of_pat(&pat))
                    let ty = it.pat()
                        .or_else(|| it.expr().and_then(|it| sema.type_of_expr(&it)))