define :item [priority, value][
    print: [
        ~"(|this\priority|, |this\value|)"
    ]
]
define :queue [items][
    init: [
        this\items: arrange this\items 'it -> it\priority
    ]
]

empty?: function [this :queue][
    zero? this\items
]

push: function [this :queue, item][
    this\items: this\items ++ item
    this\items: arrange this\items 'it -> it\priority
]

pop: function [this :queue][
    ensure -> not? empty? this

    result: this\items\0
    this\items: remove.index this\items 0
    return result
]

Q: to :queue @[to [:item] [
    [3 "Clear drains"]
    [4 "Feed cat"]
    [5 "Make tea"]
    [1 "Solve RC tasks"]
]]

push Q to :item [2 "Tax return"]

print ["queue is empty?" empty? Q]
print ""

while [not? empty? Q]->
    print ["task:" pop Q]

print ""
print ["queue is empty?" empty? Q]