@main[]

$h[ $.key[value] ]
^h.foreach[k;v]{ ^test[$h] }

@test[h]
non-blocking hash operations:

^h._count[]
$k[^h._keys[]]
$h2[^hash::create[$h]]
$b[^h.contains[key]]
^h.foreach[k;v]{$k=>$v}
^h._at(0)

blocking hash operations:

$h2[ $.k[v] ]
^try_catch{ ^h2.sub[$h] }
^try_catch{ $h.k[v] }
^try_catch{ ^h.delete[k] }

@try_catch[code]
^try{
	$code
}{
	$exception.handled(true)
	$result[Exception: $exception.source - $exception.comment]
}