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Re: How we deprecate (was Re: Deprecating '\w {' in v5.16)

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Karl Williamson
January 30, 2012 09:19
Re: How we deprecate (was Re: Deprecating '\w {' in v5.16)
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On 01/30/2012 01:06 AM, wrote:
> David Golden<>  wrote:
> :I expect that 99.9%+ of Perl users do not build dev releases (much
> :less test code on them), as much as we encourage them to.  Thus, I
> :don't expect anyone to react to a deprecation warning until the stable
> :release in which deprecation warnings start.  (Thankfully, we have
> :Andreas who regularly smokes blead because that's most of the "live
> :code" smoking we get.)
> :
> :So while I don't like "risky" code late in the dev cycle (by which I
> :mean things that are complex and might have surprising bugs revealed
> :in testing), I don't see any reason why deprecations can't be
> :introduced right up to the code freeze, since the only point it really
> :affects most users is when the stable release is done.
> I consider this deprecation risky: it may break things by being
> misimplemented, or it may break things by introducing new warnings deep
> in code that doesn't expect it. Further, I consider there is a non-zero
> probability that once we try it we may find that the practice we wish
> to deprecate is so widespread that we reconsider our approach.
> In particular, this isn't some practice that was previously dubious or
> "always broken" - as far as I know, the norm and received wisdom has
> always been "don't escape what doesn't require it".
> Attempting this at the start of a cycle would give us the space we need
> to discover whether it's a really bad idea.
> Hugo

It's not clear to me if you are referring to just the more general 
proposal to deprecate all unescaped left braces; or the more restricted 
one to deprecate those in a backslash-alpha-brace sequence.

The former has already been marked as contentious, so will not go into 
5.16.  If the latter, then it too can not be implemented in 5.16.

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