> The more I look at this, the less I like using NameArgExpr for > namespaces. It looks all wrong to me, and it causes ugly code all over. > Maybe I just need to look at it a bit longer.
I think it'd be cleaner to use ResTarget for the namespaces, like xml_attribute_el does, and split the names from actual exprs in the same way. So things like ExecInitExpr become simpler because you just recurse to initialize the list, without having to examine each element individually. tabexprInitialize can just do forboth().
The main reason I don't like abusing NamedArgExpr is that the whole comment that explains it becomes a lie.