syntax_data: {"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:         for param in params.iter() {
context_before:     pub(crate) fn parse_args(&mut self, params: &IndexSlice<ParamId, Param<'tcx>>) -> PResult<()> {
context_after:             let (var, span) = {