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RE: Fast text output from SAX?

• To: "Michael Kay" <michael.h.kay@n...>
• Subject: RE: Fast text output from SAX?
• From: Elliotte Rusty Harold <elharo@m...>
• Date: Thu, 15 Apr 2004 12:54:30 -0400
• Cc: "'XML DEV'" <xml-dev@l...>
• In-reply-to: <20040415154759.QNWQ1202.mta04-svc.ntlworld.com@Turtle>
• References: <20040415154759.QNWQ1202.mta04-svc.ntlworld.com@Turtle>

At 4:48 PM +0100 4/15/04, Michael Kay wrote:

>I personally don't think that XML parsing is that time-critical to most
>applications, but I can imagine that there are applications where avoiding
>the cost of repeatedly checking (for example) that every name is made up of
>valid characters would be beneficial.

A lot of parser use naive algorithms for this task that are far from 
the most efficient possible. For one thing, the cost of checking a 
single character can be made O(1) with a very low coefficient, at the 
cost of about 32K of memory. Furthermore, you can cache previously 
verified names and not recheck them when they're encountered 1000s of 
times apiece.

I'm not convinced even the best parsers have hit fundamental limits 
yet. It's way too early in the game to say we a binary format for 
speed purposes. Time would more productively be spent by exploring 
better algorithms for standard parsers.
-- 

   Elliotte Rusty Harold
   elharo@m...
   Effective XML (Addison-Wesley, 2003)
   http://www.cafeconleche.org/books/effectivexml
   http://www.amazon.com/exec/obidos/ISBN%3D0321150406/ref%3Dnosim/cafeaulaitA

• References:
  • RE: Fast text output from SAX?
    • From: "Michael Kay" <michael.h.kay@n...>

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