The Token production in lex.token.syntax is missing an entry for lone _ (which isn't included in IDENTIFIER_OR_KEYWORD).
Similarly the lists in macro.proc.token.macro_rules and macro.proc.token.tree are missing lone underscore, because the Reference doesn't consider "identifier" to include lone uderscore.
The
Tokenproduction inlex.token.syntaxis missing an entry for lone_(which isn't included inIDENTIFIER_OR_KEYWORD).Similarly the lists in
macro.proc.token.macro_rulesandmacro.proc.token.treeare missing lone underscore, because the Reference doesn't consider "identifier" to include lone uderscore.