`module type S = ``sig`

.. `end`

`type ``'a `

t

of_sexp and bin_io functions aren't supplied for heaps due to the difficulties in
reconstructing the correct comparison function when de-serializing.

`include ``Container.S1`

with type t := 'a t

Mutation of the heap during iteration is not supported, but there is no check to
prevent it. The behavior of a heap that is mutated during iteration is
undefined.

`val create : ``?min_size:int -> cmp:('a -> 'a -> int) -> unit -> 'a t`

`create ?min_size ~cmp`

returns a new min-heap that can store `min_size`

elements
without reallocations, using ordering function `cmp`

.The top of the heap is the smallest element as determined by the provided comparison
function. In particular, if `cmp x y < 0`

then `x`

will be "on top of" `y`

in the
heap.

Memory use is surprising in two ways:

1. The underlying pool never shrinks, so current memory use will at least be proportional to the largest number of elements that the heap has ever held.

2. Not all the memory is freed upon `remove`

, but rather after some number of
subsequent `pop`

operations. Alternating `add`

and `remove`

operations can therefore
use unbounded memory.

`val of_array : ``'a array -> cmp:('a -> 'a -> int) -> 'a t`

`min_size`

(see `create`

) will be set to the size of the input array or list.`val of_list : ``'a list -> cmp:('a -> 'a -> int) -> 'a t`

`val top : ``'a t -> 'a option`

returns the top (i.e., smallest) element of the heap

`val top_exn : ``'a t -> 'a`

`val add : ``'a t -> 'a -> unit`

`val remove_top : ``'a t -> unit`

`remove_top t`

does nothing if `t`

is empty`val pop : ``'a t -> 'a option`

This removes and returns the top (i.e. least) element

`val pop_exn : ``'a t -> 'a`

`val pop_if : ``'a t -> ('a -> bool) -> 'a option`

`pop_if t cond`

returns `Some top_element`

of `t`

if it satisfies condition
`cond`

, removing it, or `None`

in any other case.`val copy : ``'a t -> 'a t`

`copy t`

returns a shallow copy`val sexp_of_t : ``('a -> Sexplib.Sexp.t) -> 'a t -> Sexplib.Sexp.t`