On Thu, 28 Jun 2007, Wolfram Fischer wrote:
> What's really the problem with:
>
>> regexpr( '\.odt$', "xxxxYodt", perl=TRUE )
> Warning: '\.' is an unrecognized escape in a character string
> Warning: unrecognized escape removed from "\.odt$"
> [1] 5
> attr(,"match.length")
> [1] 4
>
> I know that I could use:
>> regexpr( '[.]odt$', "xxxxYodt", perl=TRUE )
>
> But it seems to me that the first expression is also
> an accepted regular expression in accordance with perl.
This is explained in ?regexp (in the See Also of ?regexpr):
Patterns are described here as they would be printed by 'cat': _do
remember that backslashes need to be doubled when entering R
character strings from the keyboard_.
and in the R FAQ and ....
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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