purrr::map(paste0(letters, collapse=""), ~purrr::map2_chr(., 1:nchar(.), ~substr(.x, 1, .y)))[[1]]
seems to crank really fast at least on my system what did you try that was slow? On Wed, Oct 19, 2016 at 11:01 AM, Witold E Wolski <wewol...@gmail.com> wrote: > Is there a build in function, which creates n suffixes of length 1:n > from string of length n? > e.g given abcd > > produces > "a" > "ab" > "abc" > > > FAST. > > equally nice to have would be: > > e.g. > given c("a", "b", "c") > produces > "a" > "a","b" > "a","b","c" > > Thank you > Witold > > > -- > Witold Eryk Wolski > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.