syntax_data: {"ast_node_type":"variable","tokens":[{"end":40,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let [a, b, c, d] = [0, 1, 2, 3];
context_before:     fn union() {
context_after:         let s = Dfa::from_edges(a, d, &[(a, 0, b), (b, 0, d), (a, 1, c), (c, 1, d)]);