[Rd] grep problem in R-devel 2.14 r57004

[Simon Urbanek]

Mark, quick googling gives the answer - [.] is not what you think it is, you probably meant [\.]. Bracket expressions starting with [. are collating symbols which is unsupported by PCRE (only [:xxx:] is supported, neither [=xxx=] nor [.xxx.] is) but that's probably not what you intended. See POSIX:

9.3.5 RE Bracket Expression
[...]
1. [..] The character sequences "[.", "[=", and "[:" (left-bracket followed by a period, equals-sign, or colon) shall be special inside a bracket expression and are used to delimit collating symbols, equivalence class expressions, and character class expressions.

Cheers,
Simon



On Sep 16, 2011, at 12:45 AM, <Mark.Bravington at csiro.au> <Mark.Bravington at csiro.au> wrote:

> Problem below with PCRE grep in R-devel; works fine in R-patched. (Unless there's been an absolutely massive change in rules for updated PCRE version 8.13; jeez I hope not)
> 
>> grep( '[.][.]', '', perl=TRUE)
> Error in grep("[.][.]", "", perl = TRUE) :
>  invalid regular expression '[.][.]'
> In addition: Warning message:
> In grep("[.][.]", "", perl = TRUE) : PCRE pattern compilation error
>        'POSIX collating elements are not supported'
>        at '[.][.]'
> 
>> sessionInfo()
> R Under development (unstable) (2011-09-13 r57004)
> Platform: i386-pc-mingw32/i386 (32-bit)
> 
> locale:
> [1] LC_COLLATE=English_Australia.1252  LC_CTYPE=English_Australia.1252
> [3] LC_MONETARY=English_Australia.1252 LC_NUMERIC=C
> [5] LC_TIME=English_Australia.1252
> 
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
> 
> NB I'm sending to R-devel rather than posting a bug report because (i) I have a dim recollection that's what we're supposed to do for bugs in R-devel, and (ii) Bugzilla doesn't include an R-devel version and (iii) couldn't find any guidance on these matters.
> 
> Mark
> 
> -- 
> Mark Bravington
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