bug#6860: allow user to see harbored smuggled fugitive LEFT-TO-RIGHT MARK hiding in his files

bug#6860: allow user to see harbored smuggled fugitive LEFT-TO-RIGHT MARK hiding in his files

[jidanni]

Another half day delay to my project due to some stupid

             character: ‎ (8206, #o20016, #x200e)
     preferred charset: unicode (Unicode (ISO10646))
            code point: 0x200E
       name: LEFT-TO-RIGHT MARK

And &%$#@ emacs cooperating with it to keep it hidden.

So how do I get it to show up?

Use the whitespace.el stuff.

Yeah well I read the whitespace.el stuff.

And it is way over my head and confusing.

All I want to do is make that D*MN LEFT-TO-RIGHT MARK character show up,

without making a whole lot of other **** show up.

As you can see in http://jidanni.org/comp/configuration/.emacs I already
tried a whole lot of times before.

As you see I already use show-trailing-whitespace t, which I'm quite
happy with.

Now all that is needed is to make LEFT-TO-RIGHT MARK show up.

I suppose for the rest of my life I will need to stare at a "WS" in the
modeline, just to catch this character.

OK, so be it. So how to make LEFT-TO-RIGHT MARK visible, without a whole
lot of other side effects?

Why can't I just assign some font symbol to it, a funny arrow or
something, so I can be aware of it lurking in my files?

Yes that is what I want. I don't want to use that whitespace jazz. I
want to be able to assign something I can see to it.

So I will send this to the enhancements request department.

I mean there can even be a symbol assigned to line wraps etc. which are
zero bytes big. Well there is this three byte big piece of s*it hiding
in my files with emacs in cahoots with the ethno-backwards writing
conspiracy to keep it hidden, with middle-east funding surely!

bug#6860: allow user to see harbored smuggled fugitive LEFT-TO-RIGHT MARK hiding in his files

[Eli Zaretskii]

> From: jidanni@jidanni.org
> Date: Sun, 15 Aug 2010 17:05:36 +0800
> Cc: 
> 
> Another half day delay to my project due to some stupid
> 
>              character: ‎ (8206, #o20016, #x200e)
>      preferred charset: unicode (Unicode (ISO10646))
>             code point: 0x200E
>        name: LEFT-TO-RIGHT MARK
> 
> And &%$#@ emacs cooperating with it to keep it hidden.
> 
> So how do I get it to show up?

Why do you care about this character more than you do about any
others?  What is so special about it that's worth half a day of your
time, and give birth to such emotions?

Anyway, characters such as LRM should be automatically composed with
the character that follows them, and then they will be invisible.  But
the necessary infrastructure in Emacs is not yet ready, so for now
they look like blanks.  This should be solved before Emacs 24 is
released.

> Use the whitespace.el stuff.

whitespace.el does not yet support this and other similar characters
(such as ZWJ).  Plan is to add them to whitespace.el, so you should be
able to use it to reveal these formatting codes, even when they are
auto-composed as described above.

> All I want to do is make that D*MN LEFT-TO-RIGHT MARK character show up,
> without making a whole lot of other **** show up.

To make it show up, or just to find it?  For the latter, you could
just search for it.

> OK, so be it. So how to make LEFT-TO-RIGHT MARK visible, without a whole
> lot of other side effects?

You could use the display tables for that.  For example:

 (aset standard-display-table ?‎ (vconcat ">"))

This will show the LRM as '>'.  You can use fancier characters in the
same manner, of course.

> Well there is this three byte big piece of s*it hiding
> in my files with emacs in cahoots with the ethno-backwards writing
> conspiracy to keep it hidden, with middle-east funding surely!

These characters are there for a reason.  Without them, display of
bidirectional text will be incorrect, sometimes entirely illegible.

bug#6860: allow user to see harbored smuggled fugitive LEFT-TO-RIGHT MARK hiding in his files

[jidanni]

OK thank you. It appears what I need to do is
(aset standard-display-table ?‎ (vconcat "♥"))
However just sticking that into one's .emacs file will cause
an error and when one uses --debug-init all one will find out is
Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
with no hint of what line that error is on (thus --debug-init has a bug:
it should say what line number in one's .emacs file it is at.)

Apparently I need to initialize standard-display-table first, perhaps
with make-char-table but of course this is all a minefield for me.

P.S., I will make this into (aset standard-display-table 8206 [9829])
as I would like to keep my .emacs file pure ASCII. I am old fashioned.

>>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
EZ> Why do you care about this character more than you do about any
EZ> others?  What is so special about it that's worth half a day of your
EZ> time, and give birth to such emotions?

Let's just say that here I am at the bakery, and I'm serving pies with
steel bolts and screws that have fallen into the dough that I cannot see
until the customer hits me with a lawsuit for a broken tooth.

And anyways, I want to be aware of every character in my files. No
hidden jazz. Currently I *can* see everything (with
show-trailing-whitespace t). There is not one single character that I am
not aware of. The worst thing currently is maybe there is a z-variant
that looks like a different character. But the rest I can all see.
Therefore it is a big boundary that emacs crosses when it is the first
time I cannot see a character. OK, I don't live in a Right to Left
country, true.

EZ> Anyway, characters such as LRM should be automatically composed with
EZ> the character that follows them, and then they will be invisible.  But
EZ> the necessary infrastructure in Emacs is not yet ready, so for now
EZ> they look like blanks.
They look like zero width nothings.
EZ> This should be solved before Emacs 24 is released.

P.S.,
(info "(emacs) Undisplayable Characters") should mention Unicode, and
perhaps this character.

(info "(emacs) Bidirectional Editing")
Says "the LRM and RLM characters display as blanks."
Zero width as of emacs-version "24.0.50.1".

(info "(elisp) Key Sequences") could perhaps mention how one can
translate the raw characters, if one wishes to keep ones .emacs file
ASCII. (I spotted the values in the debugger's output.)

OK, thanks. I know you live in .il with the BIDI stuff all day. I'm in
fact doing iconv -f utf8 -t big5 --> plucker-build to put on an old Palm
with only big5 charset. Anyway, I am aghast at the idea of "wetback"
characters hiding in my files.