Re: BUG #13310: Please update docs of regexp_replace()

On Mon, May 18, 2015 at 2:11 AM, <guettli(dot)postgres(at)thomas-guettler(dot)de>
wrote:

> The following bug has been logged on the website:
>
> Bug reference: 13310
> Logged by: Thomas Güttler
> Email address: guettli(dot)postgres(at)thomas-guettler(dot)de
> PostgreSQL version: 9.4.1
> Operating system: All
> Description:
>
> Please improve the example of regexp_replace():
>
> I am missing a "group insert" in the example.
>
> regexp_replace('fooooooobar', 'f(o*)bar', '\\1')
>
> http://www.postgresql.org/docs/9.4/static/functions-string.html

​This example assumes non-standard conforming strings. Standard conforming
strings, which are what should be documented, would give two possibilities:

regexp_replace('','', E'\\1')
or
regexp_replace('','','\1')

My personal preference is that if you do not intend to have the string
literal actually escape something the second form, without the 'E'scape
specifier, should be used.​ However, it seems that many people take the
option requiring less thought and always prepend the E''. The
documentation elsewhere, I think, tends to take that approach as
well...though I haven't gone a tried to figure out statistics.

David J.