syntax_data: {"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let inverse_memory_index = memory_index.invert_bijective_mapping();
context_before:             // Append the fields, in memory order, to the layout.
context_after:             for &field_idx in inverse_memory_index.iter() {