# File lib/active_support/json/backends/okjson.rb, line 387 def nibble(c) case true when ?0 <= c && c <= ?9 then c.ord - ?0.ord when ?a <= c && c <= ?z then c.ord - ?a.ord + 10 when ?A <= c && c <= ?Z then c.ord - ?A.ord + 10 else raise Error, "invalid hex code #{c}" end end