module Variable_queue:Priorities queues of variables.Index.PriorityQueue
with type elt = Variable.t
type
elt
type
t
val create : elt -> t
val length : t -> int
length q
is the number of elements in the queue.
length q >= 0
val is_empty : t -> bool
is_empty q
is true
iff there are no elements enqueued in q
.
is_empty q = (length q = 0)
val mem : t -> elt -> bool
mem q e
is true
iff e
is enqueued in q
.val head : t -> elt
head q
is the highest priority element of q
.
not (is_empty q)
val enqueue : t -> elt -> unit
enqueue q e
enqueues the element e
. The position of e
in q
is
determined by its priority.
Note: The default priority of elements is 0.0
.
val dequeue : t -> elt
dequeue q
removes the highest priority element from q
.
not (is_empty q)
val drop : t -> unit
drop q
removes the highest priority element from q
.
not (is_empty q)
val priority : t -> elt -> float
Note: The default priority of elements is 0.0
.
val inc_priority : t -> elt -> float -> unit
inc_priority q e x
adds x
to the priority of element e
.
If e
is enqueued, it will move up the queue as necessary.
0.0 < x
priority q e <= max_float -. x
val scale : t -> float -> unit
scale q x
multiplies the priority of every element by the constant
factor x
. The ordering of elements in the queue is unchanged.
x > 0.0
.