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Re: [O] [RFC] Alternative to sub/superscript regexp
From: |
Carsten Dominik |
Subject: |
Re: [O] [RFC] Alternative to sub/superscript regexp |
Date: |
Tue, 26 Nov 2013 10:20:20 +0100 |
Hi Nicolas,
I have tested this a bit, and it does pretty much what I want.
Just to be sure: We will also support expressions with braces, right?
- Carsten
On Nov 25, 2013, at 6:14 PM, Nicolas Goaziou <address@hidden> wrote:
> Hello,
>
> For the record `org-match-substring-regexp' is a variation on:
>
> "\\(\\S-\\)\\([_^]\\)\\(\\(?:\\*\\|address@hidden
> \t\r\n,:\"?<>~;./{}=()]+\\)\\)\\)"
>
> I think it is a bit convoluted and therefore difficult to predict. For
> example, as recent bug report showed, you may tend to interpret
> a_b[fn:1] as
>
> a_{b}[fn:1]
>
> but, in fact, it is equivalent to
>
> a_{b[fn}:1]
>
> Of course, we can prevent this by forbidding "[" and "]" in the last
> part of the regexp. But I wonder if there's something better to do.
>
> The idea behind this regexp is that we should be able to write simple
> sub/superscript, including numbers and entities, without requiring curly
> braces (see `org-use-sub-superscripts' docstring for details). Maybe
> something like the following could be an interesting alternative:
>
>
> "\\(\\S-\\)\\([_^]\\)\\(\\*\\|[+-]?\\(?:\\w\\|[0-9.,\\]\\)*\\(\\w\\|[0-9]\\)\\)"
>
> That is, without braces, either an asterisk or any combination of word,
> number, dot, comma and backslash characters, which may start with either
> a plus or a minus sign but cannot end with either a dot or a comma.
>
> I find it arguably more predictable (no inverted class). Also, we "gain"
> the following:
>
> a^3.14. <=> a^{3.14}.
>
> At the moment, a^3.14. <=> a^{3}.14.
>
> What do you think?
>
>
> Regards,
>
> --
> Nicolas Goaziou
>