syntax_data: {"ast_node_type":"variable","tokens":[{"end":93,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let fields: Vec<_> = variant_def.fields.iter().map(|f| f.name).collect();
context_before:                 .map(|(i, variant_def)| {
context_after:                     build_variant_info(Some(variant_def.name), &fields, layout.for_variant(cx, i))