package core_kernel

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Industrial strength alternative to OCaml's standard library

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core_kernel-v0.16.0.tar.gz
sha256=e37370bad978cfb71fdaf2b1a25ab1506b98ef0b91e0dbd189ffd9d853245ce2

doc/core_kernel.pairing_heap/Pairing_heap/index.html

Module Pairing_heapSource

Heap implementation based on a pairing-heap.

This heap implementations supports an arbitrary element type via a comparison function.

Sourcetype '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.

Sourceval sexp_of_t : ('a -> Sexplib0.Sexp.t) -> 'a t -> Sexplib0.Sexp.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.

include Core.Container.S1 with type 'a t := 'a t
Sourceval mem : 'a t -> 'a -> equal:('a -> 'a -> bool) -> bool
Sourceval length : 'a t -> int
Sourceval is_empty : 'a t -> bool
Sourceval iter : 'a t -> f:('a -> unit) -> unit
Sourceval fold : 'a t -> init:'acc -> f:('acc -> 'a -> 'acc) -> 'acc
Sourceval fold_result : 'a t -> init:'acc -> f:('acc -> 'a -> ('acc, 'e) Base__.Result.t) -> ('acc, 'e) Base__.Result.t
Sourceval fold_until : 'a t -> init:'acc -> f:('acc -> 'a -> ('acc, 'final) Base__Container_intf.Continue_or_stop.t) -> finish:('acc -> 'final) -> 'final
Sourceval exists : 'a t -> f:('a -> bool) -> bool
Sourceval for_all : 'a t -> f:('a -> bool) -> bool
Sourceval count : 'a t -> f:('a -> bool) -> int
Sourceval sum : (module Base__Container_intf.Summable with type t = 'sum) -> 'a t -> f:('a -> 'sum) -> 'sum
Sourceval find : 'a t -> f:('a -> bool) -> 'a option
Sourceval find_map : 'a t -> f:('a -> 'b option) -> 'b option
Sourceval to_list : 'a t -> 'a list
Sourceval to_array : 'a t -> 'a array
include Core.Invariant.S1 with type 'a t := 'a t
Sourceval invariant : 'a Base__Invariant_intf.inv -> 'a t Base__Invariant_intf.inv

Even though these two functions min_elt and max_elt are part of Container.S1, they are documented separately to make sure there is no confusion. They are independent of the comparison function used to order the heap. Instead, a traversal of the entire structure is done using the provided compare function to find a min or max.

If you want to access the smallest element of the heap according to the heap's comparison function in constant time, you should use top.

Sourceval min_elt : 'a t -> compare:('a -> 'a -> int) -> 'a option
Sourceval max_elt : 'a t -> compare:('a -> 'a -> int) -> 'a option
Sourceval 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 can be surprising in that 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.

Sourceval 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.

Sourceval of_list : 'a list -> cmp:('a -> 'a -> int) -> 'a t
Sourceval top : 'a t -> 'a option

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

Sourceval top_exn : 'a t -> 'a
Sourceval add : 'a t -> 'a -> unit
Sourceval remove_top : _ t -> unit

remove_top t does nothing if t is empty.

Sourceval clear : _ t -> unit

Removes all elements, leaving an empty heap. This operation is O(n) where n is the size of the heap.

Sourceval pop : 'a t -> 'a option

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

Sourceval pop_exn : 'a t -> 'a
Sourceval 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.

Sourceval copy : 'a t -> 'a t

copy t returns a shallow copy.

Sourcemodule Elt : sig ... end
Sourceval add_removable : 'a t -> 'a -> 'a Elt.t

add_removable t v adds v to t, returning a token that can be used to delete v from t in lg(n) amortized time.

Note that while add doesn't allocate unless the underlying pool needs to be resized, add_removable always allocates. The Unsafe module has a non-allocating alternative.

Sourceval remove : 'a t -> 'a Elt.t -> unit

If t and token are mismatched then behavior is undefined. Trying to remove an already removed token (by an earlier call to remove or pop for instance) is a no-op, but keeping token around after it has been removed may lead to memory leaks since it has a reference to the heap.

Sourceval update : 'a t -> 'a Elt.t -> 'a -> 'a Elt.t

update t token v is shorthand for remove t token; add_removable t v.

Sourceval find_elt : 'a t -> f:('a -> bool) -> 'a Elt.t option

find_elt t ~f. If f is true for some element in t, return an Elt.t for that element. This operation is O(n).

Sourcemodule Unsafe : sig ... end

Unsafe functions provide faster alternatives to regular functions with the same name. They don't allocate but the behavior is unspecified and could be memory unsafe in certain cases where regular functions would fail with informative exceptions.

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