XML alternatives [was Re: [Beowulf] What services do you run on your cluster nodes?]

Joe Landman landman at scalableinformatics.com
Fri Sep 26 15:31:35 PDT 2008

Ashley Pittman wrote:
> On Thu, 2008-09-25 at 19:11 -0400, Joe Landman wrote:
>> YAML is nice until you accidentally change indentation.  Then the game 
>> is over.  Having bolluxed up many fortran codes in my (distant past), I 
>> have to say "just say no" to things *requiring* indentation.  In YAML's 
>> case, it suffers from the same problem with Python (yeah, I am gonna get 
>> some nasty dirty emails now).  Structure by indentation is IMO *evil*. 
>> I have heard that GvR actually agrees with this, though that is 3rd 
>> order hearsay.
> I've actually come to like yaml for simple things, it's great for config
> files and other simple things like that.  Like you I'm amazed that
> Python made the same mistakes that Make did all those years ago, I

Heh... Its fun to debug Makefiles.  No... really ... :(

> thought people had realised that making whitespace significant was wrong
> long before I started in this industry!  Yaml however seems to work
> quite well, at least for simple things.

I had a case where I struggled with it for something like an hour for a 
very simple config file.  The concept is simple, the implementations are 
simple, and the emergent problems are ... well ... complex.

>> I guess, as a person who uses Perl quite a bit, I have to smile when I 
>> hear about some folks in some other language somewhere forming a team to 
>> write a parser or validator for some XML they are banging their heads 
>> on.  I am spoiled by Perl's (extraordinarily) powerful tools for stuff 
>> like this.
> Really?  I've been playing with some XML code for about two years now
> and never got it right, I've got some extensive XML I want to load into
> Perl and do things with, XML::Simple does exactly what I want and
> allowed me to write the tool I needed in a couple of days.
> Unfortunately it takes three or four minutes to load each file (there is
> one per rank) which means my tool is effectively un-usable at scale,
> I've been fiddling with XML::Parser which seems to do what I want in two
> or three seconds but is horribly complex and is incredibly difficult to
> get 100%.  Perhaps we could talk off-list and you can tell me what I've
> been doing wrong?

Can't make any guarantees, but sure.  If you would like to send me the 
XML (zip or tar.gz or bz2) I'll be happy to look at it.  Do you have a 
code that does the reading and writing?  Also, and sadly, very 
important, what platform are you running this on, and what is the output of

	perl -V

Lets take this off list.  Email me what you like (or if you don't want 
to do that, I can give you an scp account on scalableinformatics.com)


> Ashley.

Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics LLC,
email: landman at scalableinformatics.com
web  : http://www.scalableinformatics.com
phone: +1 734 786 8423 x121
fax  : +1 866 888 3112
cell : +1 734 612 4615

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