Json5Lexer._isIdentPartChar

private bool _isIdentPartChar(dchar dc) static @safe

ES5 IdentifierPart membership for a decoded code point.

Beyond alphanumerics, _, `$`, ZWNJ and ZWJ, ECMAScript also allows combining marks (Unicode categories Mn/Mc) and connector punctuation (Pc) inside identifiers — JSON5 inherits these rules (N048).