bug#15245: Search and replace, but based on text properties (inclulding face properties)

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Jambunathan K]

The underlying use-case on how such a feature could be put to good use
is explained in the following bug (which is filed against eww)

        http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15244

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Drew Adams]

> The underlying use-case on how such a feature could be put to good use
> is explained in the following bug (which is filed against eww)
> http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15244

FWIW, this feature is available in isearch+.el since 2011.
It could be incorporated into vanilla Emacs.
From the Commentary:

;;  * Ability to search within character-property zones.  Example:
;;    search within zones having a `face' text property with a value
;;    of `font-lock-comment-face' or `font-lock-string-face'.  Search
;;    overlays or text properties.  From within Isearch: `C-t' (or
;;    `C-M-t' for regexp search).  First time, or with a prefix
;;    argument, you are prompted for the property and its values.  See
;;    the doc string of command `isearchp-char-prop-forward'.
;;
;;  * Besides relying on other code to set `face' and other text
;;    properties for use with `C-t', you can use command
;;    `isearchp-put-prop-on-region' (outside of Isearch) to add a text
;;    property to a zone of text.  By default, it applies the last
;;    property and value whose zones you searched using `C-t', but a
;;    prefix arg lets you specify the property and value to apply.
;;    This gives you an interactive way to set up zones for
;;    text-property search (`C-t').  For property `face', empty input
;;    removes all faces from the region.

Code: http://www.emacswiki.org/emacs/download/isearch%2b.el
More description: http://www.emacswiki.org/IsearchPlus

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Jambunathan K]

Drew Adams <drew.adams@oracle.com> writes:

> It could be incorporated into vanilla Emacs.

Does this mean you are offering it up as a patch to Emacs?  If *yes*, I
am willing to give it a test run.

----------------------------------------------------------------

Btw, can it convert the HTML rendered by eww in to let's say Oddmuse,
Creole or Markdown formats?

By text properties, it need not necessarily be faces it can be any other
text property (that stores some data)

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Drew Adams]

> > It could be incorporated into vanilla Emacs.
> 
> Does this mean you are offering it up as a patch to Emacs?  If *yes*, I
> am willing to give it a test run.

Yes, of course.  I have offered my code generally.

> Btw, can it convert the HTML rendered by eww in to let's say Oddmuse,
> Creole or Markdown formats?

No idea, and I know almost nothing about eww, Oddmuse, and Creole.

Also, when you say "convert" it makes me realize that you asked about
search and *replace*, not just search.  Not sure what you have in mind
there.

To be clear, this feature does only search.  It just limits the
contexts to be searched to buffer zones that have given text or overlay
properties.  For example, you can search for `en' within zones that
have either face `font-lock-keyword-face' or face
`font-lock-comment-face' (or whatever).

> By text properties, it need not necessarily be faces it can be any
> other text property (that stores some data)

Correct; it is not limited to property `face'.  From the description:

  Besides relying on other code to set 'face' and other text properties
  for use with 'C-t', you can use command 'isearchp-put-prop-on-region'
  (outside of Isearch) to add a text property to a zone of text.

  By default, it applies the last property and value whose zones you
  searched using 'C-t', but a prefix argument lets you specify the
  property and value to apply. This gives you an interactive way to set
  up zones for text-property search ('C-t'). For property 'face', empty
  input removes all faces from the region.

And for properties `face' and `font-lock-face', you can pick multiple
faces, as in the example I mentioned above.  Text is searched that has
a face text (or perhaps overlay) property that includes any of the
faces you choose.

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Jambunathan K]

Drew Adams <drew.adams@oracle.com> writes:

> Also, when you say "convert" it makes me realize that you asked about
> search and *replace*, not just search.  Not sure what you have in mind
> there.

The idea is a quick and dirty to convert a text rendered by eww in to
Org format.

----------------------------------------------------------------

For example, if eww read 

    <b> bold text </b>

and converted it to

       bold text   (Imagine a bold face)

I can do a search and replace on bold text property and get 

      *bold*

which is the Org equivalent for a bold markup.

----------------------------------------------------------------

For example, if eww read 

    <h2> level 2 headline </h2>

and converted it to

       level 2 headline   (Imagine a bold face, but with text property :tag h2)

I can do a search and replace on h2 property and end up with

      ** level 2 headline

which is the Org equivalent for a headline.  If it was Creole or Oddmuse
it will be (I think) 
     
     == level 2 headline

----------------------------------------------------------------
 
This is a quick and dirty way of "importing" an HTML document in to
plain markup text.  I have a feeling that it can be useful.

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Drew Adams]

> > Also, when you say "convert" it makes me realize that you asked about
> > search and *replace*, not just search.  Not sure what you have in mind
> > there.

[snip - explanation of what was meant]

> This is a quick and dirty way of "importing" an HTML document in to
> plain markup text.  I have a feeling that it can be useful.

I see.  Well the Isearch feature I suggested won't really help with that.
You can of course use `M-%' in Isearch to kick into a query-replace.  But
`query-replace' just picks up the last search string.  It has no notion
of search contexts, AFAIK.

Now maybe things could also be tweaked to make `query-replace' respect
such contexts.  In the case of character-property searching, that would
mean making `query-replace' sensitive somehow to `isearch-filter-predicate'.

Perhaps Juri has a suggestion in this regard.  He's pretty much the
resident expert on Isearch.  Or perhaps you see a solution wrt this.

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Juri Linkov]

> Now maybe things could also be tweaked to make `query-replace' respect
> such contexts.  In the case of character-property searching, that would

It should be easy now to respect such contexts with text
properties in `query-replace' using `isearch-filter-predicate'.
I'll post an example shortly.

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Drew Adams]

> > Now maybe things could also be tweaked to make `query-replace' respect
> > such contexts.  In the case of character-property searching, that would
> 
> It should be easy now to respect such contexts with text
> properties in `query-replace' using `isearch-filter-predicate'.
> I'll post an example shortly.

Excellent.  I was hoping you might say something like that.  Haven't
been following all the changes you've made to Isearch etc. recently, but
I was wondering if something like this wasn't possible now.

bug#15245: Search and replace, but based on text properties (inclulding face properties)

[Jambunathan K]

OP here.  Closed.