Re: Patterns: Why are anchors not character classes?
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- Subject: Re: Patterns: Why are anchors not character classes?
- From: Sean Conner <sean@...>
- Date: 2015年7月18日 21:38:11 -0400
It was thus said that the Great Soni L. once stated:
> On 18/07/15 07:43 PM, Rena wrote:
> >
> >Alternation would be great, but I think it's been discussed before and
> >it would add too much complexity to the implementation.
> >
> Why not add the whole patterns to... everything?
Why not? You have Lua. You have the source code. You probably even have
LPeg if you want.
> 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. You could argue that Lua should work if you specify a reverse
range, but that's a separate argument.
> Way more powerful than Lua patterns and not that hard to write if you
> have access to tail calls. I'd take it over Lua patterns anytime, even
> if it is clunkier. We also wouldn't need "0-or-more" modifiers as you
> would be able to just x?<mod>!
I can't wait to see your code!
-spc (No one's stopping you ... )