Re: [PLUG] XML, text, and the development of unix

[Alex Birch <kes@lifesabirch.org>]

gabriel rosenkoetter wrote:

> On Tue, Nov 25, 2003 at 09:20:47AM -0500, Alex Birch wrote:
>
> > Please show me an example where seeing in XML where there is a 
> > difference between a tab or a space?
>
>
> I was generalizing the mistake. You made a syntax error, make(1)
> barfed on it. There is *more* syntax to know in XML and, thus, more
> potential for mistakes.

What's the more syntax to know with XML? I'd say there are more 
semantics but the syntax seems pretty straight forward to me.

> I don't see the "copying from a book" case as particularly relevant.
> First, the book's author, if he's teaching Makefile syntax, is
> responsible for pointing out that rule definitions need to be
> prefaced with a tab. 

I was in a hurry to create a makefile. That was my first nontrivial 
linux program. I just wanted to create a makefile that worked quickly 
and I learn best by initially copying and changing. After more 
experience I can build from scratch, but usually not the first couple of 
times.

> Second, I find it hard to believe that you
> consult a book on every XML tag that you type.

Is this a fair analogy? Wouldn't it be more appropriate to ask if I 
consulted a book or online documentation the first time I created an Ant 
file? The answer is yes, I did. Prescient and omniscient are not two of 
my attributes.

> I trust you have the same complaint against Python?

No because Python as long as you're consistent it's all good. When I was 
in Berkeley we just used two spaces, but you could use two tabs.


> > With XML at least I can SEE the difference.
>
>
> That is true, in this specific case.

That was my entire point, regarding the readability of ant versus makefile.


> > What I was thinking is just a thin wrapper and know when you're inside a 
> > tag. Then just return the tag.
>
>
> I'm not sure I understand what you mean here. Could you give an
> example of input and output?

file.xml
...
<foo att1="val1" att2="val2">
grepValue
</foo>
<foo att1="val1" att2="val2">
another value
</foo>

Then if I did xgrep -i "grepvalue" file.xml

It would produce:
<foo att1="val1" att2="val2">
grepValue
</foo>

the wrapper would realize that grepValue was inside of the <foo></foo> tags.


> > What other traditional tools would be nice? xsed? xgrep?
>
>
> Weren't we discussing xgrep? (Did you mean xawk?)

I was thinking of all the possible friends of xgrep and other line 
oriented text manipulation files.

> I think sed and awk's functionality doesn't necessarily map cleanly
> onto XML. When I use xawk, do I want the whole tag, do I want the
> contents of the tag, what? 

Why not have both? have special fields map to the values? $v1, $v2 while 
the $0 maps to the entire tag. This could allow people to quickly get 
the tag and value that they want.


> When I use xsed, do I want only to
> replace tag names? Do I want to replace tag values? There're some
> serious interface questions that would need to be considered to
> adhere to the principle of least surprise.

That's why I'm trying to get feedback before I start a project like 
this. If I hope to see as far as others, I must stand on the backs of 
giants.

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