syntax_data: {"ast_node_type":"variable","tokens":[{"end":30,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let len = s.len();
context_before:             let s = s.as_str().as_bytes();
context_after:             let allocation = tcx.allocate_bytes_dedup(s, CTFE_ALLOC_SALT);