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

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Karl Williamson
January 30, 2012 11:33
Re: How we deprecate (was Re: Deprecating '\w {' in v5.16)
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On 01/30/2012 10:18 AM, Karl Williamson wrote:
> 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.

BTW, one advantage of doing either of these is that people have 
complained, and their may be tickets open on (don't have time just now 
to check) that if they make a typo in a {quantifier}, there's no 
message.  Now there would be, and we could close any of those tickets

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