what's intangibility in move-end-of-line?

what's intangibility in move-end-of-line?

[Xah Lee]

 aboutin the inline doc for move-end-of-line, it says:

«
move-end-of-line is an interactive compiled Lisp function in
`simple.el'.
It is bound to M-D.
(move-end-of-line arg)

Move point to end of current line as displayed.
(If there's an image in the line, this disregards newlines
which are part of the text that the image rests on.)

With argument arg not nil or 1, move forward arg - 1 lines first.
If point reaches the beginning or end of buffer, it stops there.
To ignore intangibility, bind `inhibit-point-motion-hooks' to t.
»

this seems unclear to me. What is this intangibility? looking up on
inhibit-point-motion-hooks does not seems to clear up. It seems about
some properties in lisp symbols.

I need to use this in elisp code. Not sure if it is proper to use in
elisp code.

Thanks.

  Xah
∑ http://xahlee.org/

☄

Re: what's intangibility in move-end-of-line?

[Kevin Rodgers]

Xah Lee wrote:
>  aboutin the inline doc for move-end-of-line, it says:
> 
> «
> move-end-of-line is an interactive compiled Lisp function in
> `simple.el'.
> It is bound to M-D.
> (move-end-of-line arg)
> 
> Move point to end of current line as displayed.
> (If there's an image in the line, this disregards newlines
> which are part of the text that the image rests on.)
> 
> With argument arg not nil or 1, move forward arg - 1 lines first.
> If point reaches the beginning or end of buffer, it stops there.
> To ignore intangibility, bind `inhibit-point-motion-hooks' to t.
> »
> 
> this seems unclear to me. What is this intangibility? looking up on
> inhibit-point-motion-hooks does not seems to clear up. It seems about
> some properties in lisp symbols.

No, text properties.  You can read about them in the Emacs Lisp manual.
The "Special Properties" says this about intangibility:

,----
| `intangible'
|      If a group of consecutive characters have equal and non-`nil'
|      `intangible' properties, then you cannot place point between them.
|      If you try to move point forward into the group, point actually
|      moves to the end of the group.  If you try to move point backward
|      into the group, point actually moves to the start of the group.
|
|      If consecutive characters have unequal non-`nil' `intangible'
|      properties, they belong to separate groups; each group is
|      separately treated as described above.
|
|      When the variable `inhibit-point-motion-hooks' is non-`nil', the
|      `intangible' property is ignored.
`----

> I need to use this in elisp code. Not sure if it is proper to use in
> elisp code.

Sure it is.  Or (goto-char (line-end-position))

-- 
Kevin Rodgers
Denver, Colorado, USA