UNI_MAX_LEGAL_UTF32   26 ext/json/ext/generator/unicode.h #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF
UNI_MAX_LEGAL_UTF32   15 ext/json/ext/parser/unicode.h #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF