Re: Sort List of Maps By Key Value

Thanks--that's very helpful. I will cogitate on this more.

Cheers,

E.

--
Eliot Kimber
http://contrext.com


o;?On 9/29/18, 4:51 PM, "Michael Kay mike@xxxxxxxxxxxx"
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

    >
    > I'm still trying to get my head around how to use the "?" operator

    If you think of a map as being like an element with attributes but no name
and no children, then unary "?" behaves like unary "@", while binary "?"
behaves like "/@"

    Compare

    let $e := (<e x="1" y="2" z="3"/>, <e x="10" y="20" z="30"/>

    let $m := (map{"x":1, "y":2, "z":3}, map{"x":10, "y":20, "z":30})

    then $m?x corresponds to $s/@x (returning (1, 10))

    and $m[?x = 1]?y corresponds to $e[@x = 1]/@y (returning 2)

    The analogy starts to break down for dynamic references:

    $m?($key) corresponds to $e/@*[name()=$key] (But you can also write it as
$m($key) to save one keystroke)

    Michael Kay
    Saxonica