With the addition of higher order functions and the discussion around adding map values, SequenceTypes are becoming more and more complex - especially when building complex data structures from these types of values.
We should add a type alias (or type definition) facility to allow complex SequenceType to be referred to with simple QNames, and to allow the definition of recursive types:
declare type-alias my:transform-function as
function($nodes as node()*, $params as map(*)) as item()*;
We discussed this in meeting #523 and decided this is a "may" requirement.
Q2.9.17 Bugzilla Bug 17602, [XQ31ReqUC] Type alias / define
may (for maps)
This bug has been redirected to the XQuery 3.1 document, as it has been accepted as a MAY requirement.
In their teleconference of 2014-04-22, the Working Group decided that this MAY requirement would not be satisfied in the XQuery 3.1 timeframe. As a consequence, I am marking the bug RESOLVED/LATER.
In their teleconference of 2014-04-22, the Working Group decided that this MAY requirement would be reconsidered for any future version of XQuery, should such future version materialize. As a consequence, I am recategorizing this bug as Requirements for Future Versions.