[R] Split String in regex while Keeping Delimiter

Eric Berger
2023-04-12T17:32:53Z

This seems to do the job but there are probably more elegant solutions:

f <- function(s) { sub("^
","",unlist(strsplit(gsub("\\+ ","+@
",s),"@"))) }
g <- function(s) { sub("^
","",unlist(strsplit(gsub("- ","-@
",s),"@"))) }
h <- function(s) { g(f(s)) }

To try it out:
s <- ?leucocyten + gramnegatieve staven +++ grampositieve staven ++?
t <- ?leucocyten ? grampositieve coccen +?

h(s)
h(t)

HTH,
Eric


On Wed, Apr 12, 2023 at 7:56?PM Emily Bakker <emilybakker at outlook.com>
wrote:

> Hello List,
>
> I have a dataset consisting of strings that I want to split while saving
> the delimiter.
>
> Some example data:
> ?leucocyten + gramnegatieve staven +++ grampositieve staven ++?
> ?leucocyten ? grampositieve coccen +?
>
> I want to split the strings such that I get the following result:
> c(?leucocyten +?,  ?gramnegatieve staven +++?,  ?grampositieve staven ++?)
> c(?leucocyten ??, ?grampositieve coccen +?)
>
> I have tried strsplit with a regular expression with a positive lookahead,
> but I am not able to achieve the results that I want.
>
> I have tried:
> as.list(strsplit(x, split = ?(?=[\\+-]{1,3}\\s)+, perl=TRUE)
>
> Which results in:
> c(?leucocyten ?, ?+?,  ?gramnegatieve staven ?, ?+?, ?+?, ?+?,
>  ?grampositieve staven ++?)
> c(?leucocyten ?, ???, ?grampositieve coccen +?)
>
>
> Is there a function or regular expression that will make this possible?
>
> Kind regards,
> Emily
>
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