A debugging puzzle with XML

A debugging puzzle with XML

[Marcin Borkowski]

Hi there,

as we all know, everything is better with XML, so here's a puzzle for
all interested (I call it a puzzle and not a bug because I finally
solved it).

Download the xmlgen library (https://github.com/philjackson/xmlgen) and
execute this code:

(require 'xmlgen)
(with-temp-file "foo.xml"
  (insert (xmlgen '(hello (world (of (xml) "!")))))).

Visit file foo.xml, do this:

C-x h M-x sgml-pretty-print

and enjoy your beautifully formatted (and indented!) XML code.

Now rinse and repeat, but with one change:

(require 'xmlgen)
(with-temp-file "foo.xml"
  (insert (xmlgen '(hello (world (of (xml) "!")))))
  (sgml-pretty-print (point-min) (point-max)))

and answer this question: where have all the indents go?

;-D

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: A debugging puzzle with XML

[Nicolas Richard]

Marcin Borkowski <mbork@wmi.amu.edu.pl> writes:
> (require 'xmlgen)
> (with-temp-file "foo.xml"
>   (insert (xmlgen '(hello (world (of (xml) "!")))))
>   (sgml-pretty-print (point-min) (point-max)))
>
> and answer this question: where have all the indents go?

Ok let's play the game (i.e. I didn't try) : My guess is that since
`with-temp-file' doesn't set the major mode (i.e. it will be
fundamental-mode), there are local variables which are not set as
sgml-pretty-print would expect.

-- 
Nicolas Richard

Re: A debugging puzzle with XML

[Marcin Borkowski]

On 2015-01-29, at 11:46, Nicolas Richard <theonewiththeevillook@yahoo.fr> wrote:

> Marcin Borkowski <mbork@wmi.amu.edu.pl> writes:
>> (require 'xmlgen)
>> (with-temp-file "foo.xml"
>>   (insert (xmlgen '(hello (world (of (xml) "!")))))
>>   (sgml-pretty-print (point-min) (point-max)))
>>
>> and answer this question: where have all the indents go?
>
> Ok let's play the game (i.e. I didn't try) : My guess is that since
> `with-temp-file' doesn't set the major mode (i.e. it will be
> fundamental-mode), there are local variables which are not set as
> sgml-pretty-print would expect.

Good catch!  To be more precise: sgml-pretty-print calls
reindent-then-newline-and-indent, which depends on the mode.

It took me almost half an hour of frustration...  I guess this is just
another step on the path to real Emacs expertise, which I hope to finish
within a two-digit number of years...  (That assuming that "finishing"
it is at all possible.)

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University