/*!
* versions.js 0.2
*
* Copyright (c) 2009 Adaptavist.com
* Dual licensed under the MIT and GPL licenses.
*
* http://www.adaptavist.com/display/~mgibson/Versions
*/
/* Allow multiple versions of self-contained libraries to exist.
*
* Author: Mark Gibson (jollytoad at gmail dot com)
*/
(window.Versions || (function() {
 
var v;
v= window.Versions = {
 
library: {},
 
// Register an object under a given name and version numbers
add: function ( name, versions, object ) {
var vers = versions.split(/\s+/),
lib = v.library[name] || {};
 
while (vers.length) {
lib[vers.shift()] = object;
}
 
v.library[name] = lib;
 
// Should this return the registered object, or Versions (for chaining),
// or nothing at all?
},
 
// Retrieve a object by name and version
use: function ( name, version ) {
return v.library[name][version] ||
v.error("non-existent library version: "+name+"-"+version);
},
 
// Break a version number down in stages - down to a given level
// Suitable for passing into Versions.add.
//
// eg. Versions.cascade('1.3.4.2', 2, 'latest') returns "latest 1.3.4.2 1.3.4 1.3"
cascade: function ( version, level, extra ) {
var points = version.split('.'),
i = points.length,
ret = extra ? [extra] : [];
 
while ( i >= (level || 2) ) {
ret.push(points.slice(0, i).join('.'));
i++;
}
 
return ret.join(' ');
},
 
debug: false,
 
error: function(msg) {
if ( v.debug ) {
if ( window.console ) {
(console.error||console.log)(msg);
} else if ( window.opera && opera.postError ) {
opera.postError(msg);
} else {
alert(msg);
}
}
}
 
};
 
})());