[R] : regular expressions: escaping a dot

[Peter Dalgaard]

Prof Brian Ripley wrote:
>
>
> 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 ....
>
>   
Hmm, that's not actually correct, is it? Perhaps this is better

"...entering R character string literals (i.e., between quote symbols.)"

The counterexample would be

> readLines()
\\abc
[1] "\\\\abc"

(of course it is more important to get people to read the documentation
at all...)

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