getFirstInstance

Funtion to get the first instance of a familySymbol

(
$getFirstInstance := function($parentId) {
    (
        $first := $[type = "FamilyInstance" and parent.id = $parentId][0];
        $exists($first) ? 
        $map($filter($keys($first.values), function($key) {
            $substring($key, 0, 2) = "p_"
        }), function($key) {
            $substring($key, 2)  /* Remove the "p_" prefix */
        }) : []
    )
};
$filter(
    $[type = "FamilySymbol"].{
        "type": type,
        "id": id,
        "name": name,
        "mergedSharedParameters": $append(
            $getFirstInstance(id),
            $map($filter($keys($.values), function($key) {
                $substring($key, 0, 2) = "p_"
            }), function($key) {
                $substring($key, 2)  /* Remove the "p_" prefix */
            })
        )
    },
    function($symbol) {
        $exists($symbol.mergedSharedParameters)
    }
)