There is no pseudo-code in the documentation. All of the documentation code executes as documented.

The library works with type names in two naming modes - default and compact. The default name scheme uses the full type names, such as 'positive_integer', while the compact name scheme uses compact names, such as 'int+' for 'positive_integer'.

You can only be in one mode or the other at any one time. You can switch between the two using the xtype.setOptions method:

    xtype(5);    // 'positive_integer'
    
    // Switch to compact name scheme:
    xtype.setOptions({nameScheme:'compact'});
    
    xtype(5);    // 'int+'
    

See this jsbin I've made for this specific piece of code - http://jsbin.com/kixuko/1/edit?html,js,console.

And the documentation for switching between the default and compact name schemes - https://github.com/lucono/xtypejs/blob/master/docs/Usage.md#....