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- Subject: Re: Patterns: Why are anchors not character classes?
- From: Sean Conner <sean@...>
- Date: Sun, 19 Jul 2015 05:35:29 -0400
It was thus said that the Great Soni L. once stated:
> On 18/07/15 10:38 PM, Sean Conner wrote:
> >It was thus said that the Great Soni L. once stated:
> > >
> > >Guess
> > >what [a-%%] would do? It would match anything from 'a' to the '%' sign!
> > >(which you can't currently do, because %% is a character class!)
> > It can't do that now because 'a' to '%' isn't a range. '%' is 37, 'a'
> > is 97, so of course:
> > x = '%'
> > print(x:match"[a-%%]"))
> >fails. But if you do:
> > x = '%'
> > print(x:match"[%%-a]"))
> >it works.
> Actually the manual says it's undefined.
The actual text is:
The interaction between ranges and classes is not defined.
Therefore, patterns like [%a-z] or [a-%%] have no meaning.
But! There is this:
%x: (where x is any non-alphanumeric character) represents the
character x. This is the standard way to escape the magic
characters. Any non-alphanumeric character (including all
punctuations, even the non-magical) can be preceded by a '%' when
used to represent itself in a pattern.
So to me, that says that '%%' is NOT a class and can therefore be used as
mentioned. I wonder what Roberto meant by the example of "[a-%%]". Perhaps