ACTION-2020: Propose what to do if serialization in serialize()

All,

I had this action [1] for the serialize() function [2]. This was discussed
in a couple of emails [3] and [4]. There was a question of whether going
with a lax or strict serialization (a lax one being one that never fails).
Alain thought that lax was not a great idea, and pointed to the fact that
XPath 3's `serialize()` function does raise dynamic errors. [5]

So I think the natural way to go is to stay with the solution of raising a
dynamic error if a problem occurs. The text currently says:

    " the xforms:json or xforms:csv method is specified and serialization
fails, a dynamic error is raised."

We could leave the current text in, but I took the liberty of changing the
text to match XPath 3 more closely:

    "If any serialization error occurs, including the detection of an
invalid value for a serialization parameter, this results in the
xf:serialize() call failing with a dynamic error."

Diff:


https://www.w3.org/community/xformsusers/wiki/index.php?title=XPath_Expressions_Module&diff=226&oldid=225

-Erik

[1] https://www.w3.org/2015/09/09-forms-minutes.html#item09
[2]
https://www.w3.org/community/xformsusers/wiki/XPath_Expressions_Module#The_serialize.28.29_Function
[3] https://lists.w3.org/Archives/Public/public-forms/2015Apr/0008
[4]
https://lists.w3.org/Archives/Public/public-xformsusers/2015Apr/0006.html
[5] https://www.w3.org/TR/xpath-functions-30/#func-serialize