unicode_normalize

Unicode Normalization—Returns a normalized form of str, using Unicode normalizations NFC, NFD, NFKC, or NFKD. The normalization form used is determined by form, which can be any of the four values :nfc, :nfd, :nfkc, or :nfkd. The default is :nfc.

If the string is not in a Unicode Encoding, then an Exception is raised. In this context, ‘Unicode Encoding’ means any of UTF-8, UTF-16BE/LE, and UTF-32BE/LE, as well as GB18030, UCS_2BE, and UCS_4BE. Anything other than UTF-8 is implemented by converting to UTF-8, which makes it slower than UTF-8.

"a\u0300".unicode_normalize        #=> "\u00E0"
"a\u0300".unicode_normalize(:nfc)  #=> "\u00E0"
"\u00E0".unicode_normalize(:nfd)   #=> "a\u0300"
"\xE0".force_encoding('ISO-8859-1').unicode_normalize(:nfd)
                                   #=> Encoding::CompatibilityError raised