xmlformat is distributed under a BSD-style license.  This license
applies to the entire xmlformat distribution, with the exception of
the REX parser (described below).

Copyright (c) 2004, 2005, Kitebird, LLC.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

3. Neither the name of Kitebird nor the names of its contributors may
   be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
The REX parser

xmlformat contains code based on the REX parser, which is Copyright (c) 1998,
Robert D. Cameron.  REX is described in this document:

	http://www.cs.sfu.ca/~cameron/REX.html

The document contains a Perl implementation of REX:

--- begin REX code ---
# REX/Perl 1.0 
# Robert D. Cameron "REX: XML Shallow Parsing with Regular Expressions",
# Technical Report TR 1998-17, School of Computing Science, Simon Fraser 
# University, November, 1998.
# Copyright (c) 1998, Robert D. Cameron. 
# The following code may be freely used and distributed provided that
# this copyright and citation notice remains intact and that modifications
# or additions are clearly identified.

$TextSE = "[^<]+";
$UntilHyphen = "[^-]*-";
$Until2Hyphens = "$UntilHyphen(?:[^-]$UntilHyphen)*-";
$CommentCE = "$Until2Hyphens>?";
$UntilRSBs = "[^\\]]*](?:[^\\]]+])*]+";
$CDATA_CE = "$UntilRSBs(?:[^\\]>]$UntilRSBs)*>";
$S = "[ \\n\\t\\r]+";
$NameStrt = "[A-Za-z_:]|[^\\x00-\\x7F]";
$NameChar = "[A-Za-z0-9_:.-]|[^\\x00-\\x7F]";
$Name = "(?:$NameStrt)(?:$NameChar)*";
$QuoteSE = "\"[^\"]*\"|'[^']*'";
$DT_IdentSE = "$S$Name(?:$S(?:$Name|$QuoteSE))*";
$MarkupDeclCE = "(?:[^\\]\"'><]+|$QuoteSE)*>";
$S1 = "[\\n\\r\\t ]";
$UntilQMs = "[^?]*\\?+";
$PI_Tail = "\\?>|$S1$UntilQMs(?:[^>?]$UntilQMs)*>";
$DT_ItemSE =
"<(?:!(?:--$Until2Hyphens>|[^-]$MarkupDeclCE)|\\?$Name(?:$PI_Tail))|%$Name;|$S";
$DocTypeCE = "$DT_IdentSE(?:$S)?(?:\\[(?:$DT_ItemSE)*](?:$S)?)?>?";
$DeclCE =
"--(?:$CommentCE)?|\\[CDATA\\[(?:$CDATA_CE)?|DOCTYPE(?:$DocTypeCE)?";
$PI_CE = "$Name(?:$PI_Tail)?";
$EndTagCE = "$Name(?:$S)?>?";
$AttValSE = "\"[^<\"]*\"|'[^<']*'";
$ElemTagCE = "$Name(?:$S$Name(?:$S)?=(?:$S)?(?:$AttValSE))*(?:$S)?/?>?";
$MarkupSPE =
"<(?:!(?:$DeclCE)?|\\?(?:$PI_CE)?|/(?:$EndTagCE)?|(?:$ElemTagCE)?)";
$XML_SPE = "$TextSE|$MarkupSPE";


sub ShallowParse { 
  my($XML_document) = @_;
  return $XML_document =~ /$XML_SPE/g;
}
--- end REX code ---

The Perl and Ruby implementations of xmlformat contain parsers that
are based on the preceding code and are essentially the same, with the
exception of changes to variable and function names.

