Great to know this exists in package space!
Of course, using re2 validation for a regex to be executed with TRE
(via grep*) is just begging for trouble (e.g. [1] suggests re2 is
closer to PCRE, [2] says "mostly" PCRE compatible). And overhauling
everything to use re2 just for regex validation is h
Hi Michael, it sounds like you don't want to use a CRAN package for
this, but you may try re2, see below.
> grepl("(invalid","subject",perl=TRUE)
Error in grepl("(invalid", "subject", perl = TRUE) :
invalid regular expression '(invalid'
In addition: Warning message:
In grepl("(invalid", "subject
> Grepping an empty string might work in many cases...
That's precisely why a base R offering is important, as a surer way of
validating in all cases. To be clear I am trying to directly access the
results of tre_regcomp().
> it is probably more portable to simply be prepared to propagate such
er
On 10/10/23 01:57, Michael Chirico via R-devel wrote:
> It will be useful to package authors trying to validate input which is
> supposed to be a valid regular expression.
>
> As near as I can tell, the only way we can do so now is to run any
> regex function and check for the warning and/or cond
On 09/10/2023 7:57 p.m., Michael Chirico via R-devel wrote:
It will be useful to package authors trying to validate input which is
supposed to be a valid regular expression.
As near as I can tell, the only way we can do so now is to run any
regex function and check for the warning and/or conditi
It will be useful to package authors trying to validate input which is
supposed to be a valid regular expression.
As near as I can tell, the only way we can do so now is to run any
regex function and check for the warning and/or condition to bubble
up:
valid_regex <- function(str) {
stopifnot(i
