Map.Make.3o man page

Map.Make — Functor building an implementation of the map structure given a totally ordered type.

Module

Module Map.Make

Documentation

Module Make
: functor (Ord : OrderedType) -> sig end

Functor building an implementation of the map structure given a totally ordered type.

Parameters:

"Ord"

Map.OrderedType

type key

The type of the map keys.

type +'a t

The type of maps from type key to type 'a .

val empty : 'a t

The empty map.

val is_empty : 'a t -> bool

Test whether a map is empty or not.

val mem : key -> 'a t -> bool

mem x m returns true if m contains a binding for x , and false otherwise.

val add : key -> 'a -> 'a t -> 'a t

add x y m returns a map containing the same bindings as m , plus a binding of x to y . If x was already bound in m to a value that is physically equal to y , m is returned unchanged (the result of the function is then physically equal to m ). Otherwise, the previous binding of x in m disappears.

Before4.03 Physical equality was not ensured.

val singleton : key -> 'a -> 'a t

singleton x y returns the one-element map that contains a binding y for x .

Since 3.12.0

val remove : key -> 'a t -> 'a t

remove x m returns a map containing the same bindings as m , except for x which is unbound in the returned map. If x was not in m , m is returned unchanged (the result of the function is then physically equal to m ).

Before4.03 Physical equality was not ensured.

val merge : (key -> 'a option -> 'b option -> 'c option) -> 'a t -> 'b t -> 'c t

merge f m1 m2 computes a map whose keys is a subset of keys of m1 and of m2 . The presence of each such binding, and the corresponding value, is determined with the function f .

Since 3.12.0

val union : (key -> 'a -> 'a -> 'a option) -> 'a t -> 'a t -> 'a t

union f m1 m2 computes a map whose keys is the union of keys of m1 and of m2 . When the same binding is defined in both arguments, the function f is used to combine them.

Since 4.03.0

val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int

Total ordering between maps. The first argument is a total ordering used to compare data associated with equal keys in the two maps.

val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool

equal cmp m1 m2 tests whether the maps m1 and m2 are equal, that is, contain equal keys and associate them with equal data. cmp is the equality predicate used to compare the data associated with the keys.

val iter : (key -> 'a -> unit) -> 'a t -> unit

iter f m applies f to all bindings in map m . f receives the key as first argument, and the associated value as second argument. The bindings are passed to f in increasing order with respect to the ordering over the type of the keys.

val fold : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b

fold f m a computes (f kN dN ... (f k1 d1 a)...) , where k1 ... kN are the keys of all bindings in m (in increasing order), and d1 ... dN are the associated data.

val for_all : (key -> 'a -> bool) -> 'a t -> bool

for_all p m checks if all the bindings of the map satisfy the predicate p .

Since 3.12.0

val exists : (key -> 'a -> bool) -> 'a t -> bool

exists p m checks if at least one binding of the map satisfy the predicate p .

Since 3.12.0

val filter : (key -> 'a -> bool) -> 'a t -> 'a t

filter p m returns the map with all the bindings in m that satisfy predicate p . If p satisfies every binding in m , m is returned unchanged (the result of the function is then physically equal to m )

Before4.03 Physical equality was not ensured.

Since 3.12.0

val partition : (key -> 'a -> bool) -> 'a t -> 'a t * 'a t

partition p m returns a pair of maps (m1, m2) , where m1 contains all the bindings of s that satisfy the predicate p , and m2 is the map with all the bindings of s that do not satisfy p .

Since 3.12.0

val cardinal : 'a t -> int

Return the number of bindings of a map.

Since 3.12.0

val bindings : 'a t -> (key * 'a) list

Return the list of all bindings of the given map. The returned list is sorted in increasing order with respect to the ordering Ord.compare , where Ord is the argument given to Map.Make .

Since 3.12.0

val min_binding : 'a t -> key * 'a

Return the smallest binding of the given map (with respect to the Ord.compare ordering), or raise Not_found if the map is empty.

Since 3.12.0

val max_binding : 'a t -> key * 'a

Same as Map.S.min_binding , but returns the largest binding of the given map.

Since 3.12.0

val choose : 'a t -> key * 'a

Return one binding of the given map, or raise Not_found if the map is empty. Which binding is chosen is unspecified, but equal bindings will be chosen for equal maps.

Since 3.12.0

val split : key -> 'a t -> 'a t * 'a option * 'a t

split x m returns a triple (l, data, r) , where l is the map with all the bindings of m whose key is strictly less than x ; r is the map with all the bindings of m whose key is strictly greater than x ; data is None if m contains no binding for x , or Some v if m binds v to x .

Since 3.12.0

val find : key -> 'a t -> 'a

find x m returns the current binding of x in m , or raises Not_found if no such binding exists.

val map : ('a -> 'b) -> 'a t -> 'b t

map f m returns a map with same domain as m , where the associated value a of all bindings of m has been replaced by the result of the application of f to a . The bindings are passed to f in increasing order with respect to the ordering over the type of the keys.

val mapi : (key -> 'a -> 'b) -> 'a t -> 'b t

Same as Map.S.map , but the function receives as arguments both the key and the associated value for each binding of the map.

Info

source: 2016-11-23 OCamldoc