There probably is a package with such a function, but you can do with one call to sub() if you parenthesize all the subexpressions in the regular expression and use \\1, etc., in the replacement for those parts you want to keep. E.g.,
> s <- "<div data-pos=\"Untitled.knit.md@12:1-13:1\">" > want <- "<div data-pos=\"newname@newnumber:1-13:1\">" > new_regexp <- "(.*<[^>]+ data-pos=\")([^\"]*)(@)([[:digit:]]+)(:.*)" > all.equal( sub(new_regexp, "\\1newname\\3newnumber\\5", s), want) [1] TRUE -Bill On Tue, Oct 25, 2022 at 10:12 AM Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > An R regular expression pattern can contain parenthesized > subexpressions, and those can be used later in the same pattern, or in > the replacement in sub() and gsub(). What I'd like to do is match > several subexpressions and replace all of them. > > For example, I might have a string like > > s <- "<div data-pos=\"Untitled.knit.md@12:1-13:1\">" > > and I can use the regular expression > > regexp <- ".*<[^>]+ data-pos=\"([^\"]*)@([[:digit:]]+):.*" > > to match the whole thing, with \\1 matching "Untitled.knit.md" and \\2 > matching "12". I'd like to replace the first with "newname" and the > second with "newnumber", so the string ends up looking like > > s <- "<div data-pos=\"newname@newnumber:1-13:1\">" > > I could write a function to do this using regexec() and two calls to > `substring<-`(), but I'm hoping someone has already done that. Any > suggestions? > > Duncan Murdoch > > P.S. I'm going to be travelling for a couple of weeks, and so may not > respond right away. > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.
