syntax_data: {"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let dst_layout = into_layout(dst_alts.clone());
context_before:             for dst_alts in alts.clone().into_iter().powerset().filter(|alts| !alts.is_empty()) {
context_after:                 let dst_set = into_set(dst_alts.clone());