Function decode_unquoted_key 

pub(crate) fn decode_unquoted_key<'i>(
    raw: Raw<'i>,
    output: &mut dyn StringBuilder<'i>,
    error: &mut dyn ErrorSink,
)

Parse unquoted key

unquoted-key = 1*( ALPHA / DIGIT / %x2D / %x5F ) ; A-Z / a-z / 0-9 / - / _