KXF: The Koala XML Form

2026-08-30T00:00:00+00:00

Legacy

A blast from the past... In the last century, when we wrote XML by hand, I designed a format to get rid of one of XML multiple annoyances: as it used ordinary characters as deleimters, such as <, >, &, it means often quoting hell.

The idea: Use non-ascii-7bits characters as markup!

Use «foo» to delimit tags, instead of <foo></foo>
Use these regular elements as escape sequences instead of entities. Escape « by «-». Not really readable — but more than entities — but natural and consistent to parse.

I wrote the KXF <-> XML converter in Klone, my lisp scripting language, that I definitely need to publish here as part of these legacy series.

Here is the doc of the format:

KXF: The Koala XML Form

Purpose

The Koala XML Form XML avatar has been defined with the following design goals:

Ease writing by hand
Ease human readability
Solve only syntaxic problems
- no entities
- no DTD
- no CDATA
- straightforward whitespace handling
- get rid of most quoting hell: use less special chars, and use non ascii ones

Design

Here are some examples:

KXF	XML
«tag»	<tag/>
«tag foo <> bar»	<tag>foo < > bar</tag>
«tag(x=y z="1 2" t='gp') gee»	<tag x='y' y='1 2' t='gp'>gee</tag>
«! comments»	<!-- comments -->
«? PIs»	<?PIs?>

Quoting special chars:

Char	Quoted form	Where
«	«-»	character data contents
»	«+»	character data contents
'	«!»	attribute values
'	«/»	attribute values
"	«#»	attribute values
"	«*»	attribute values

»«/tag» optional ending forms can be used to check nesting as in
«foo a very big contents... »«/foo»
- ending contents is ignored and can be used for comments, as in:
  «foo a very big contents... »«/foo the main loop»
- attributes if present must match the starting tag attributes:
  «foo(x=1) a very big contents... »«/foo(x=1)» matches, but
  «foo a very big contents... »«/foo(x=2)» raises an error
Whitespace around sub-elements are discarded, but not around character data.
You can keep them by postfixing element name with = (it sets the xml:space attribute to "preserve"), such as
«pre=(a=b) «b x» «i y»» or by enclosing them in the pseudo node «= »
«x «= » «y» «z»» keeps space before y, but not between y and z
For comfortable use, it is recommended to assign «» to shift-keypad-minus and shift-keypad-plus respectively
Encodings are raw: either ISO-Latin-1, or UCS2, which can be autodetected as fields must begin with «<letter> (ISO-Latin-1), \0« (UCS2), «\0 (MS UCS2)

Benefits

More readable
Most text editors know how to balance « and » better than <foo> and </foo>
It is self sufficient: whitespace handling is explicit
No need to quote the common chars <, >, &

Drawbacks

You cannot use XML Tools on this format. Not really a problem, as you can convert to and from XML

Tools

For now, there exists only a parser/writer in Klone (xml-ksf.kl, used to implement Klone scripts (xml2kxf, kxf2xml) that converts back and forth to XML.

A java SAX parser is planned

Author

Colas Nahaboo

Back to XML Avatars

Colas.Nahaboo.net - xml

KXF: The Koala XML Form

KXF: The Koala XML Form

Purpose

Design

Benefits

Drawbacks

Tools

Author