The following code: res <- gsub("(*UCP)\\b(i)\\b", "", "nhgrimelanomaclass", perl = TRUE)
results in: Error in gsub(sprintf("(*UCP)\\b(%s)\\b", "i"), "", "nhgrimelanomaclass", : invalid regular expression '(*UCP)\b(i)\b' In addition: Warning message: In gsub(sprintf("(*UCP)\\b(%s)\\b", "i"), "", "nhgrimelanomaclass", : PCRE pattern compilation error 'this version of PCRE is not compiled with Unicode property support' at '(*UCP)\b(i)\b' on R Under development (unstable) (2015-01-01 r67290) Platform: x86_64-apple-darwin13.4.0 (64-bit) Running under: OS X 10.9.5 (Mavericks) locale: [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base And also on the same version of R-devel on Snow Leopard, Windows, and Linux. But it does not produce an error on R version 3.1.2 (2014-10-31) Platform: x86_64-apple-darwin13.4.0 (64-bit) locale: [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base Dan ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel