This is a binding of expat to MOO providing two functions for parsing XML.

It was written by Ken Fox <fox@mars.org>.

This patch's "home page" (for now) is
   http://www.xythian.com/moo/expat-binding/

expat is an XML Parser Toolkit available at 
   http://www.jclark.com/xml/expat.html

The binding is covered under the following license:

--- 

Copyright 2000 by Ken Fox.   All rights reserved.

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation.

KEN FOX DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
KEN FOX BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.

---

See the expat home page for the expat license.

To use this modification:
1)  Get expat.zip from the site above.  Unzip it.  Compile it.  Remember
    where this directory is.

2)  Get the latest LambdaMOO server (1.8.1) from 
    http://download.sourceforge.net/lambdamoo/LambdaMOO-1.8.1.tar.gz
    and unpack it into its own directory.

3)  Get the expat-binding distribution from
    http://www.xythian.com/moo/expat-binding/dist/ext-xml-1.0.tar.gz
    and unpack it into its own directory.

4)  Copy the following files from the ext-xml directory to the MOO-1.8.1
    directory: ext-xml.c
               ext-xml.patch

5)  cd to where you unpacked the MOO server and copied ext-xml.c and 
    ext-xml.patch

6)  Apply the patch: patch < ext-xml.patch
    Included in the distribution are my copies of the modified 1.8.1 files
    for reference.   
    The modified files are:
         storage.h   - added xml data storage type 
         Makefile.in - added ext-xml.c to CSRCS and added refs to expat code
         extensions.c - added lines to call register_xml
    The rest of the binding lives in ext-xml.c.

7)  Edit Makefile.in: find where it says 
    EXPAT = /home/fox/src/dist/expat
    And modify it to point to where you unpacked expat.zip.

8)  ./configure and make as usual.

There are two new functions once this is installed:
  LIST xml_parse_tree(STR string)
  LIST xml_parse_document(STR string)
  
Both return a list of the form:
   {tag, attributes alist, text, children}
where:
   STR tag            - tag name
   LIST attributes    - alist of attributes {{STR key, STR value}, ...}
   STR text           - text between the tags
   LIST children      - children of this node

The difference between xml_parse_tree and xml_parse_document lies in
where text between tags ends up.  xml_parse_tree puts it all in the
"text" element of the node.  xml_parse_document puts it in the
children element.  This may be clearer with examples.  The indendation
of the return values is for illustrative purposes only.

;xml_parse_tree("<XML>abc</XML>") 
=> {{"XML",        -- tag name
     {},           -- attribute alist 
     "abc",        -- text
     {}}}          -- children

;xml_parse_tree("<list><item>foo</item><item>bar</item></list>") 
=> {{"list",       -- tag name of root
     {},           -- attributes
     "",           -- text
     {{"item",     -- tag name of first child
       {},         -- attributes of first child 
       "foo",      -- text of first child
       {}          -- children of first child 
      },         
      {"item",     -- tag name of second child
       {},         -- attributes of second child
       "bar",      -- text of second child
       {}          -- children of second child
      }           
     }             -- end of children of root
    }
   }

;xml_parse_document("<document coolness=\"yes\">The <EM>brown cow</EM> " +
                    "lept over " +
                    "the <EM>blue moon</EM></document>") 
=> {"document",
    {{"coolness", "yes"}},
    "",
    {"The ",
     {"EM", {}, "", {"brown cow"}}
     "lept over ",
     {"EM", {}, "", {"blue moon"}}
    }}