[YANG] mandatory empty

Andy Bierman <ietf@andybierman.com> Mon, 04 February 2008 18:16 UTC

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Date: Mon, 04 Feb 2008 10:17:45 -0800
From: Andy Bierman <ietf@andybierman.com>
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Subject: [YANG] mandatory empty
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Hi,

What does this mean exactly?

   leaf foo {
     type empty;
     mandatory true;
   }

Does this translate to:

   <element name='foo' minOccurs='0'/>

The empty data type can be modeled in XSD as an empty complexType:

   <complexType name='empty'/>

Can it be modeled as a simpleType?

   <simpleType name='empty'>
     <restriction base='xs:string'>
       <maxLength value='0'/>
     </restriction>
   </simpleType>


If mandatory means that the manager must supply a value,
then the leaf 'foo' can never be missing.

Even if it means the agent must supply a value,
it still seems strange.  Perhaps more text is needed
about the empty data type.

IMO, 'mandatory' and 'units' are not applicable to built-in type 'empty'.


Andy
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