Declarative complex attribute values

[borela]

Sorry if this has been sugested before; Other markup languages like XAML allows attribute values to be expanded:

<Complex 
  someAttribute={
    <SubComponent>Some text value...</SubComponent>
  }
>
  Some children...
</Complex>

Would turn into something like this:

<Complex>
  <Complex@someAttribute>
    <SubComponent>Some text value...</SubComponent>
  <Complex@someAttribute>
  Some children...
</Complex>

The <Complex@someAttribute> would just affect the attribute's value; The symbol @ was chosen for demonstration purposes only but it could be anything else.