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Postings from July 2016
* Father Chrysostomos via RT <perlbug-followup@perl.org> [2016-07-11 17:36]: > On Mon Jul 11 07:39:18 2016, demerphq wrote: > > On 11 Jul 2016 10:13, "Dave Mitchell" <davem@iabyn.com> wrote: > > > 1) leave literal // with its 'last regex' behaviour for now > > > > I would like to deprecate it in m// but keep it in s/// where it at > > least has some utility. > > I would prefer to keep it in both, since it makes it simpler to > explain. I went back and forth over this a bit. My initial inclination was the same as yours: the less special a special case is, the better. But when I imagined making that claim, I realised it doesn’t really help in his situation: we already have a special case, and you just have to memorize what works where. There already isn’t much systematic about it. And in a way it could even be easier to understand and explain if the reuse-last-pattern thing was a feature of s/// and didn’t clog the rest of the documentation. There would be just one kind of operation where you ever saw this in code, and it would look suitably odd to signal that something unusual is going on (“how could a substitution of nothing have an effect?”) and the documentation for that operation is the place that would explain it. Simple and coherent and discoverable. It almost makes the feature sound like a good idea! But my next realisation was that we’re not in a vacuum: code may have to work across Perl versions. And documentation has to explain the issues relating to that. Both tasks are easier if divergences are kept small. So ultimately I think adding reuse-last-pattern as a special feature of s/// (and s///) alone would make sense if we were starting from scratch, but keeping it in m// is preferable given that we do have a historical context and that the context is what it is. Regards, -- Aristotle Pagaltzis // <http://plasmasturm.org/>Thread Previous