syntax_data: {"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: ///   for `ctxt_or_parent_or_marker`, but larger crates might need more than 16
context_before: ///   the form of the code. No crates in `rustc-perf` need more than 15 bits
context_after: ///   bits. The number of bits needed for `parent` hasn't been measured,