syntax_data: {"ast_node_type":"variable","tokens":[{"end":40,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:     if let Some(decl) = node.fn_decl() {
context_before:     let node = tcx.hir_node_by_def_id(def_id);
context_after:         decl.inputs.iter().map(|ty| ty.span).chain(iter::once(decl.output.span()))