[Xpath-ng] List constructor syntax

[David Rosenborg]

David Carlisle wrote:

> 
>   foo="{validate{$bar}}"
> 
> The obvious solution there (over in xpath2 land)is to make validate a
> normal function, it is as far as I know the only use of {} in Xpath (as
> opposed to query) and just sticks out like a sore thumb.

Yes, but the validate expression and the expressions where I think braces
could be used, like in node constructors are unlikely to appear as the
direct child of an AVT in practice.  foo="{element bar {'baz'}}"
wouldn't make much sense. And for those insisting on doing this,
they could get away with an extra space as in foo="{element bar {'baz'} }"
or an extra pair of parenthesis foo="{(element bar {'baz'})}". Not
a perfect solution, but I think braces will prove too valuable to exclude
from the language in general in the long run. We just have to be
careful to where we introduce them.

Cheers,
David