stri_extract_all('XaaaaX', regex=c('\\p{Ll}', '\\p{Ll}+', '\\p{Ll}{2,3}', '\\p{Ll}{2,3}?'))
stri_extract_all('Bartolini', fixed='i')
stri_extract_all('stringi are so good!', charclass='Zs') # all whitespaces
Run the code above in your browser using DataLab