syntax_data: {"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// more convenient and has some nice properties. The basic idea is to
context_before:     /// various ways you can do this, but a De Bruijn index is one of the
context_after:     /// count the number of binders, inside out. Some examples should help