Re: parens matching not matching all matching parens

[Arjan Bos]

Greg Hill wrote:

> At 9:19 PM +0200 9/16/04, Arjan Bos wrote:
>
> > Hi all,
> >
> > I'm currently developing yet another rich text format writer. And as 
> > you might know, RTF is using curly braces a lot. Alas, every now and 
> > then, a normal parentheses pops up between a set of matching {}. Both 
> > the parens matching colouring and the forward-sexp / backward-sexp 
> > can't handle this. How can I (help to) solve this?
> >
> > An rtf snippet is included here:
>
> > {\rtf1\mac\ansicpg10000\uc1
> > {\*\pnseclvl4\pnlcltr\pnstart1\pnindent720\pnhang{\pntxta )}}}
>
> > This is a complete piece of (non-sensical, but correct) rtf. The first 
> > `{' matches the last `}'. Only C-M-f jumps from the first `{' to the 
> > one-to-last `}'.
>
> > I'm wondering if this is a bug or not.
> >
> > TIA,
>
> > Arjan
>
>
> Arjan,
>
> Personally, I would call it a bug in the 'scan-sexps built-in function, 
> which is called by 'forward-sexp, which is normally bound to "C-M-f".  
> For some reason 'scan-sexps seems to treat a ")" as matching a "{".  You 
> might want to submit a bug report, but there is no guanentee the 
> maintainers of Emacs will not call that odd behavior a "feature."

Thanks,
I'll submit a bug.

> On the other hand, if you just want to get on with life, you can try 
> putting something like the following code in your .emacs file.  The 
> 'defun defines a function that scans forward for the first '(', '[', '<' 
> or '{' following point, whatever it see first, then scans for a matching 
> closing character, ignoring any other characters.  The '(setq 
> forward-sexp-function... effectively replaces the guts of 'forward-sexp 
> with the new function, so you will not have to rebind your keystroke.  
> It works in the backward direction as well ("C-M-b").
<snip gone="code"/>


> I should warn you, by the way, that I just hacked this code together in 
> a few minutes after work tonight, and have not tested it exhuastively.  
> Let me know if you have any questions or problems.

Greg,

I already had something similar. Looking at the current bracket under 
point, finding its opposite and start counting the brackets you 
encounter. Another of the same bracket ups the ante, the opposite pops 
one from the ante. When the ante is empty, all bets are off, and the 
bracket is found.

My code isn't perfect, so I will borrow heavily from yours.

Thanks!
> --Greg


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