[xquery-talk] operations on derived numeric type

[Michael Sokolov]

On 08/30/2013 07:11 AM, Benito van der Zander wrote:
> Hi,
> is it true that *all* operations on types derived from the numeric 
> types return a value of one of the four base numeric types?
> For example xs:byte(1) + xs:byte(1) or abs(xs:byte(1)).
>
> What's the point of even having these sub types then?

It's really a headache to use the subtypes since you are constantly 
fighting against the grain.  For example, if you write a function like:

declare function local:factorial($x as xs:int) as xs:int {
   if ($x < 2) then 1 else local:factorial($x - 1) * $x
}

You get various compilation errors

You have to do something like:

declare function local:factorial($x as xs:int) as xs:int {
   if ($x < 2) then xs:int(1) else xs:int(local:factorial(xs:int($x - 
1)) * $x)
};

local:factorial (xs:int(10))

This is using Saxon 9.4.  Somehow in MarkLogic there seems to be some 
kind of automatic casting going on, and the first function compiles and 
runs OK.

-Mike

PS how many times will I forget that $x-1 is parsed as a variable name.  
A token allowed in a symbol *and* as an operator makes no sense.  Old 
argument I'm sure.