Scanning parenthesis in string/comment

Scanning parenthesis in string/comment

[Yuan Fu]

I’m writing an expand-region-like function, which expands region by logical entities, like word-at-point, list-at-point, etc. Say I have this string

"Filter out invalid regions in REGIONS regarding ORIG.
ORIG is the current position. Each region is (BEG . END).”

And point is at the opening parenthesis, how do I detect this balanced parenthesis pair and expand the region over it? syntax-pass and forward-list only works with lists outside of strings and comments, IIUC.

Yuan

Re: Scanning parenthesis in string/comment

[Ruijie Yu via Users list for the GNU Emacs text editor]

Yuan Fu <casouri@gmail.com> writes:

> I’m writing an expand-region-like function, which expands region by logical entities, like word-at-point, list-at-point, etc. Say I have this string
>
> "Filter out invalid regions in REGIONS regarding ORIG.
> ORIG is the current position. Each region is (BEG . END).”
>
> And point is at the opening parenthesis, how do I detect this balanced
> parenthesis pair and expand the region over it? syntax-pass and forward-list
> only works with lists outside of strings and comments, IIUC.
>
> Yuan

Based on what I remember reading from the relevant info pages and
docstrings, is it possible that you start a new syntax scan that starts
*at point* and ends *before the ending quotes*?  IIUC the function
`parse-partial-sexp' might be what you should look into next.

Best,


RY

Re: Scanning parenthesis in string/comment

[Yuan Fu]

> On Jan 22, 2023, at 5:49 PM, Ruijie Yu <ruijie@netyu.xyz> wrote:
> 
> 
> Yuan Fu <casouri@gmail.com> writes:
> 
>> I’m writing an expand-region-like function, which expands region by logical entities, like word-at-point, list-at-point, etc. Say I have this string
>> 
>> "Filter out invalid regions in REGIONS regarding ORIG.
>> ORIG is the current position. Each region is (BEG . END).”
>> 
>> And point is at the opening parenthesis, how do I detect this balanced
>> parenthesis pair and expand the region over it? syntax-pass and forward-list
>> only works with lists outside of strings and comments, IIUC.
>> 
>> Yuan
> 
> Based on what I remember reading from the relevant info pages and
> docstrings, is it possible that you start a new syntax scan that starts
> *at point* and ends *before the ending quotes*?  IIUC the function
> `parse-partial-sexp' might be what you should look into next.

Thanks, that seems to be the way to go.

> What I understand is that you use thing-at-point similar functions, so
> why not then define your own think at point in the sense as here below:
> 
> ;;; Thing at point 'thing-within-quotes
> 
> (defun rcd-tap-thing-within-quotes-start ()
>    "Move point to the beginning of thing within quotes."
>  (re-search-backward (rx (or "\"" "'")))
>  (forward-char 1))
> 
> (defun rcd-tap-thing-within-quotes-end ()
>    "Move point to the end of thing within quotes."
>  (re-search-forward (rx (or "\"" "'")))
>  (backward-char 1))
> 
> (put 'thing-within-quotes 'beginning-op 'rcd-tap-thing-within-quotes-start)
> (put 'thing-within-quotes 'end-op 'rcd-tap-thing-within-quotes-end)
> 
> Then the above will give you whatever is inside of quotes you define
> when you apply function:
> 
> (thing-at-point 'thing-within-quotes)
> 
> on it, and it will not work well outside of quotes.

Yeah I can find the range of the string and do a parse inside. Thanks!

Yuan

Re: Scanning parenthesis in string/comment

[Jean Louis]

* Yuan Fu <casouri@gmail.com> [2023-01-22 20:17]:
> I’m writing an expand-region-like function, which expands region by logical entities, like word-at-point, list-at-point, etc. Say I have this string
> 
> "Filter out invalid regions in REGIONS regarding ORIG.
> ORIG is the current position. Each region is (BEG . END).”
> 
> And point is at the opening parenthesis, how do I detect this
> balanced parenthesis pair and expand the region over it? syntax-pass
> and forward-list only works with lists outside of strings and
> comments, IIUC.

What I understand is that you use thing-at-point similar functions, so
why not then define your own think at point in the sense as here below:

;;; Thing at point 'thing-within-quotes

(defun rcd-tap-thing-within-quotes-start ()
    "Move point to the beginning of thing within quotes."
  (re-search-backward (rx (or "\"" "'")))
  (forward-char 1))

(defun rcd-tap-thing-within-quotes-end ()
    "Move point to the end of thing within quotes."
  (re-search-forward (rx (or "\"" "'")))
  (backward-char 1))

(put 'thing-within-quotes 'beginning-op 'rcd-tap-thing-within-quotes-start)
(put 'thing-within-quotes 'end-op 'rcd-tap-thing-within-quotes-end)

Then the above will give you whatever is inside of quotes you define
when you apply function:

(thing-at-point 'thing-within-quotes)

on it, and it will not work well outside of quotes.

-- 
Jean

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