new unicode regex flags.js

// ## like \1 but named:
/(?<fruit>apple|fig)==\k<fruit>/u.test('fig==fig')
// true


// ## named group captures:
'we can'.replace(/(?<subject>\w+) (?<verb>\w+)/u, '$<subject>...$<verb>')
//"we...can"

'yes, we can'.replace(/(?<w>\w+)[,\s]+/gu, '$<w>...')
// "yes...we...can"

'2018-03-28'.match(/(?<y>\d{4})-(?<m>\d{2})-(?<d>\d{2})/u).groups
// {y: "2018", m: "03", d: "28"}