documents or examples on defining / adding a new syntax?

[Zhang Weiwu <zhangweiwu@realss.com>]

Here is what I can find about defining / adding a new syntax.

Peter Marschall wrote on Sat, 5 Jul 2003
> Defining a new syntax means defining a new form of data structure that the 
> server must know about. This is not possible using only configration 
> options. You need to code it into the server.  Of course the same holds 
> for matching rules.

Howard Chu wrote on 2002-10-25
> if you had originally configured with --enable-modules, You need to create 
> a dynamic module that calls register_syntax() with your new syntax 
> definition, and then use moduleload in slapd.conf to load your module.

My question is:

1. is there a module that introduces a new syntax, from which I could 
observe how that is done?

2. Is there any document on what-to-be-aware-of if you design a new syntax?

3. Do I need to design a new syntax at all? My requirement is the following:

	I need a new syntax for ranged-values. Examples are:

	- netWeight: 12~13kg
	- ISOSensitivity: 800~1600
	- heightAdjustableRange: 1.2m~1.5m

	The spec of ranged-value is a numeric, optionally followed by a
	measurement unit, followed by a tild as seperatorâ, followed by
	another measurement.

	The syntax needs its own comparison rules, so that you can filter a
	range, and get entries who offer values ranging in that range.


â quote from http://en.wikipedia.org/wiki/~
	In some languages (though not English), a tilde-like wavy dash may
	be used as punctuation (instead of an unspaced hyphen or en-dash)
	between two numbers, to indicate a range rather than subtraction or
	a hyphenated number (such as a part number or model number).