[plt-scheme] SXML vs. X-expressions

From: Gordon Weakliem (gordon.weakliem at gmail.com)
Date: Fri Oct 22 14:18:16 EDT 2004

Structurally, they're a pretty different. 

<span class="foo"><a href="http://plt-scheme.org">PLT</a> is wonderful</span>

becomes 

(*TOP*
 (span
  (@ (class "foo"))
  (a (@ (href "http://plt-scheme.org")) "PLT")
  " is wonderful"))

while xml->xexpr yields

(span
 ((class "foo"))
 (a ((href "http://plt-scheme.org")) "PLT")
 " is wonderful")

There's differences in how things like comments and PIs are handled as
well.  SSAX has a number of libraries for doing things like XPath
processing, and is implemented on a number of Schemes.  SSAX has a
highly customizable parser, and there are tools like HtmlPrag for
trying to make sense of badly formed XML.  I tend to use SSAX, but the
xml collection is a bit simpler and I've used it for things where I
didn't need XPath and didn't want to mess with SSAX.

BTW, I was pleasantly surprised that SSAX is now part of the PLT
distro.  Thank you, thank you, thank you!

On Fri, 22 Oct 2004 13:30:25 -0400, Doug Orleans <dougo at place.org> wrote:
>   For list-related administrative tasks:
>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> 
> Forgive me if this is a FAQ, but what exactly is the relationship
> between SXML and PLT's X-expressions?  Are they two competing ways of
> doing the same thing, or are there reasons to use both?  I've been
> doing XML programming with just (lib "xml.ss" "xml"), but I'm
> wondering if I should switch to SXML/SSAX.
> 
> --dougo at place.org
>


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