7 - identifier.class: "fn [a-z0-9_]+"
8 - statement: "\\b(abstract|alignof|as|become|box|break|const|continue|crate|do|else|enum|extern|false|final|fn|for|if|impl|in|let|loop|macro|match|mod|move|mut|offsetof|override|priv|pub|pure|ref|return|sizeof|static|self|struct|super|true|trait|type|typeof|unsafe|unsized|use|virtual|where|while|yield)\\b"
9 - identifier.macro: "[a-z_]+!"
10 - constant: "[A-Z][A-Z_]+"
11 - constant.number: "\\b[0-9]+\\b"
13 - constant.string: "\\\".*\\\""
35 - todo: "(XXX|TODO|FIXME|\\?\\?\\?)"