[ jEdit-devel ] [ jedit-Bugs-2332140 ] Colon causes unnecessary indent in python

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Bugs item #2332140, was opened at 2008-11-23 02:23
Message generated for change (Comment added) made by axis3x3
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100588&aid=2332140&group_id=588

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including the initial issue submission, for this request,
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Category: text area and syntax packages
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Altonator (altonator)
Assigned to: Jarek Czekalski (jarekczek)
Summary: Colon causes unnecessary indent in python

Initial Comment:
In python if you type

if whatever:
    print 'something'
print 'something with a colon:

It assumes that the second print statement should be indented as well, so when you type the : (electric key) it indents the line.  This is really annoying!!  I've had a look at the python.xml file in the 'modes' directory and played around with the regexes, but either I'm shit at regular expressions or the solution isn't that simple.  If you remove the 'electrickeys' tag then it removes the problem but it ruins all other indentation cleverness.  Nothing else seems to fix it.  There's no 'indentThisLine' tag, so why does it indent it?

Weak!


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Comment By: Andy Balaam (axis3x3)
Date: 2012-04-20 09:56

Message:
For what it's worth, I too find the current behaviour extremely annoying,
and would be very happy if electric keys were disabled in Python mode.

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Comment By: Rick R. (rick-r)
Date: 2012-04-18 17:07

Message:
Actually, I don't think the first option ("too sensitive" electric keys
with unindentThisLine) would solve anything in this case because I can't
figure out how construct a regular expression that could possibly prevent
changing the indentation in any of the cases I outlined. I don't believe
this issue can be resolved satisfactorily without more context than the
current line. Having said that, however, you made a proposal in ID #
3514076 (disable electric keys on a per-mode basis) that makes the most
sense to me. That's essentially what I've been doing by hacking the
python.xml file in the modes directory. Right now, that's the only thing
that makes any sense to me.

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Comment By: Jarek Czekalski (jarekczek)
Date: 2012-04-18 10:34

Message:
As fas as I know braces have no indenting meaning in python and should be
removed from the mode file.

Regarding the colon, here is a less drastic proposal:
https://sourceforge.net/tracker/index.php?func=detail&aid=1936678&group_id=588&atid=100588
("too sensitive" electricKeys with unindentThisLine)

Jedit's mode indenting rules do not allow for backwards analysis. They only
use regular expressions on current line and this probably won't change. So
only simple solutions are possible. What would be your suggestion for a
simple solution? Consider 2 tracker entry links I posted.

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

Comment By: Rick R. (rick-r)
Date: 2012-04-18 10:29

Message:
Arrg, that first example is wrong. Should have read

if c1:
....stmt
....if c2:
........stmt
........else:

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

Comment By: Rick R. (rick-r)
Date: 2012-04-18 10:25

Message:
Yeah, I didn't think about 'else'. Applies (or should apply) to 'elif',
'except' and 'finally', too.

Unfortunately, I don't see a way to make this function 100% without the
addition of, say, a mind-reading API. There's no way to determine the
programmer's intent just by examining the syntax. For example,

if c1:
....stmt
    if c2:
........stmt
........else:

Which 'if' should the else be associated with? Only the programmer knows
for certain, but jEdit keeps making assumptions that I personally find
annoying. Given the above situation, when I type the ':' after the else,
jEdit will undent to match the second if, and I end up with

if c1:
....stmt
....if c2:
........stmt
....else:

Which is certainly OK sometimes. But, when I know that the 'else' needs to
be associated with the outer if condition, I will almost always undent to
the correct level *before* typing the else statememt


if c1:
....stmt
....if c2:
........stmt
else|              (here's where I am just *before* typing the colon; this
is where I want the else)

but after typing the colon, I end up with

if c1:
....stmt
....if c2:
........stmt
....else:

which is not what I intended. I guess what I'm getting at here is that
jEdit needs to examine more of the context to find out if the current
location *could* be a syntactically correct location for the keyword
('else', 'elif', 'except', 'finally'). If so, leave it alone. If not, make
an adjustment if and only if an adjustment makes sense. 

Right now, jEdit appears to scan backwards until it finds the first
matching 'if' statement. I think it needs to go further than that, possibly
to the beginning of the current function, to see if the current position
could be acceptable. If it doesn't find a matching 'if' (or 'while' or
'try', ...) unobtrusively warn the user (i.e., no pop-ups) and do nothing.
If the position could be valid, do nothing. If it's obvious that the
position is wrong (e.g., only one matching construct found), then adjust
the indentation.

Another other issue that I think needs to be addressed is that the colon
(and other electric keys) shouldn't have any effect inside a comment or
quoted string. Again, this is a context issue.

As far as the braces and brackets are concerned, I don't understand why
those are electric at all in python. Maybe it's just the way I format my
code, but I think those should be removed as electric keys.

I apologize for the length of this comment, but there's a lot going on
here. Thanks for listening. ;-)

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

Comment By: Jarek Czekalski (jarekczek)
Date: 2012-04-17 23:19

Message:
electricKeys are responsible for the unwanted behaviour. Sorry for the
mistake I made in previous tests, because I prefer to work on hacked jedit
with electricKeys off. See
https://sourceforge.net/tracker/?func=detail&atid=350588&aid=3514076&group_id=588

However there is a case in which you want them to work. It's for
unindentThisLine section in python.xml. Thanks to the electric keys you may
type:

if asdfas:
....something
else:
....uiwuerw

And this gets automatically indented. So it's not obvious in python's case
to remove electricKeys absolutely. What do you suggest, Rick?

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

Comment By: Rick R. (rick-r)
Date: 2012-04-17 18:03

Message:
I don't see that this is fixed at all. If I type

if cond1:
....stmt

and press Enter, my cursor ends up under the 's' in stmt, as expected. But
if I unindent so that my cursor is under the i in 'if', as in

if cond1:
....stmt
|                             (the '|' character represents the cursor)

then type

if cond2:

as soon as I type the colon, I end up with

if cond1:
....stmt
....if cond2:

which, in this case, is not what I intended. In fact, the exact same thing
happens with braces and brackets, which I mentioned earlier. I can't think
of a case where I'd ever want any character to change the indentation of
the line on which I'm currently typing. Subsequent lines, sure, but not the
current line. That's essentially the same thing that Alternator said below
on 2008-12-27 10:22:34 PST.

I tested on jEdit 4.5.1 with the distributed python mode file.

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

Comment By: Jarek Czekalski (jarekczek)
Date: 2012-04-11 04:51

Message:
Seems like the original issue is fixed. I'm testing on jedit 4.5. If you
wish to report a problem with braces indentation, please make it a new bug
entry.

To test this issue make sure you use the original python mode file.

If however this is not fixed please make a new example, but use dots or
underlines instead of spaces, because those are eaten by bug tracker
software.

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

Comment By: Rick R. (rick-r)
Date: 2012-01-07 15:09

Message:
Well, I found that if I comment out the following lines in <jEdit install
dir>/modes/python.xml

		<PROPERTY NAME="indentOpenBrackets" VALUE="{[" />
		<PROPERTY NAME="indentCloseBrackets" VALUE="}]" />

and

		<PROPERTY NAME="electricKeys" VALUE=":" />

that my indentation issues appear to go away. Of course, I haven't spent
much time with it, yet...

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

Comment By: Rick R. (rick-r)
Date: 2012-01-07 14:08

Message:
I can definitely reproduce it with jEdit 4.5pre1. In fact, it's not just a
colon that breaks the indentation. jEdit reindents the second line when I
type an open brace '{', a close brace '}', an open bracket '[', or a close
bracket ']', in addition to a colon.

I do a *lot* of python coding, and while I like jEdit for most things, I
avoid it for python because of the auto-indentation issues.

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

Comment By: Alan Ezust (ezust)
Date: 2011-12-03 11:25

Message:
I can not reproduce any of your issues with jEdit 5.0pre1.
Is this still an issue for you?



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

Comment By: Altonator (altonator)
Date: 2008-12-27 10:22

Message:
Thanks kpouer, that's really useful to know.  I do think there's a better
way though.  Whether the modes xml system will allow it to be implemented
I'm not sure, but I'll try to explain it...

Currently, when you type:
[code]
if something:
    print 'pie'
if bananas
[/code]
And then you type ":" on the end, it will become

[code]
if something:
    print 'pie'
    if bananas:
[/code]

So it's indenting the line when you type the colon(:).  Is there any
situation in python where you would want it to indent the current line when
you type a colon?  Ever?

And so (assuming you answer 'no' to the above question), why not just
remove the indentThisLine thing, or whatever it is that tells it to indent
the line when you type a colon?

When you type
[code]
if bananas:
[/code]
it doesn't indent the current line (that would be silly), no, it just
indents the next line (useful).  And if you type
[code]
if bananas:
    print 'pie'
    if cheese
[/code]
then it automatically indents those next two lines WHEN YOU HIT RETURN. 
There's no indenting of the current line going on.  It's all done as you
press return.  So if you UN-indent the 'if cheese' line, there's no reason
for it to re-indent it when you type a colon.  No need!  What use would
that ever be?  All the indenting should be done when you press return, once
return is pressed the indenting should be left alone (in the case of if:
type stuff), surely?

I had a play with the python.xml mode, but didn't get far with it.  Maybe
you would be able to sort the dog out?
Altonator

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

Comment By: SourceForge Robot (sf-robot)
Date: 2008-12-11 18:20

Message:
This Tracker item was closed automatically by the system. It was
previously set to a Pending status, and the original submitter
did not respond within 14 days (the time period specified by
the administrator of this Tracker).

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

Comment By: Alan Ezust (ezust)
Date: 2008-11-27 08:58

Message:
I can only reproduce this if the previous line ends with :,  *AND* I did a
shift indent left
on the line (outdenting) before I type :. In that case, I see it re-indents
my line in one level from the previous line.

Perhaps that rule kicks in under other circumstances, but I don't know
enough about mode files to say more about it at this time. I will play
around some more. But your test case is not sufficient to reproduce it. It
seems to depend on

1. what is on the previous line
2. whether you did a shift+indent on the line you are editing at the
moment.






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

Comment By: Matthieu Casanova (kpouer)
Date: 2008-11-27 05:24

Message:
Hi, automatic indentation in python is very difficult, we added a
convention for that : if you add an empty line after the "if" block the
next one will not be indented :

[code]
if something:
    print 'pie'
if bananas
[/code]

When you type ":" will become


[code]
if something:
    print 'pie'
    if bananas:
[/code]

but if you have this


[code]
if something:
    print 'pie'

if bananas
[/code]

typing the ":" will not indent your if bananas.
It is the best compromise we found, if you have better ideas, let us know

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

Comment By: Altonator (altonator)
Date: 2008-11-26 14:21

Message:
A much simpler, and more likely way to trigger this bug is this...
[code]
if something:
    print 'pie'
if bananas:
[/code]

When you type that last colon it indends the line.  But it doesn't do it
with...
[code]
if something:
    print 'pie'
else:
[/code]

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

Comment By: Altonator (altonator)
Date: 2008-11-25 11:20

Message:
Have tested using the generic Java-based installer as well.  Behaviour is
the same.

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

Comment By: Altonator (altonator)
Date: 2008-11-25 11:13

Message:
I've just tried your example code below... when I type out line 5, as soon
as I put that : on the end it indents the line, so you end up with:
[code]
if something:
    print 'something with a : in quotes'    
    next line:
        indented as expected;
        print 'something ending with a quoted colon:
[/code]


jEdit 4.3pre16 using Java 1.5.0_16 on Mac OS X 10.4.11.

ezust, what version of jEdit are you using?

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

Comment By: Alan Ezust (ezust)
Date: 2008-11-25 10:23

Message:
I am unable to reproduce your problem also.
It seems to work fine for me. it indents the NEXT line if the line ends on
an unquoted colon, which is the only time it is supposed to.
I think (let's hope it works) you can put a 
[code]
if something:
    print 'something with a : in quotes'    
    next line:
        indented as expected;
    print 'something ending with a quoted colon:
    next line is not indented
[/code]

let's see if it works.


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

Comment By: Altonator (altonator)
Date: 2008-11-23 12:07

Message:
Hi, sorry, should have put that in.  I was using 4.3pre15, but I've just
downloaded 4.3pre16 and the issue still occurs.  Ah, what I've written wont
make sense because Sourceforge has helpfully removed all of the spaces so
you can't see which bits are indented!
When you type out the example indent the second line (so it's part of the
if clause), but don't indent the last one.  When you type that last colon
jEdit indents that line as well.  Lame.  (This actually makes it part of
the if clause as python uses the indent rather than {} to determine the
bounds of if/else clauses, so it not only looks wrong, but it breaks your
code if you don't correct it!)


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Comment By: Matthieu Casanova (kpouer)
Date: 2008-11-23 05:27

Message:
Hi, what version of jEdit do you use ? I just tried with 4.3pre16 and I
cannot reproduce (or maybe I did not understand exactly what you mean ?)

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

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100588&aid=2332140&group_id=588