include Map.Sval empty : 'a tThe empty map.
val is_empty : 'a t -> boolTest whether a map is empty or not.
mem x m returns true if m contains a binding for x, and false otherwise.
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.
singleton x y returns the one-element map that contains a binding y for x.
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).
merge f m1 m2 computes a map whose keys are a subset of the keys of m1 and of m2. The presence of each such binding, and the corresponding value, is determined with the function f. In terms of the find_opt operation, we have find_opt x (merge f m1 m2) = f x (find_opt x m1) (find_opt x m2) for any key x, provided that f x None None = None.
union f m1 m2 computes a map whose keys are a subset of the keys of m1 and of m2. When the same binding is defined in both arguments, the function f is used to combine them. This is a special case of merge: union f m1 m2 is equivalent to merge f' m1 m2, where
f' _key None None = Nonef' _key (Some v) None = Some vf' _key None (Some v) = Some vf' key (Some v1) (Some v2) = f key v1 v2Total ordering between maps. The first argument is a total ordering used to compare data associated with equal keys in the two maps.
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.
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.
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.
for_all p m checks if all the bindings of the map satisfy the predicate p.
exists p m checks if at least one binding of the map satisfies the predicate p.
filter p m returns the map with all the bindings in m that satisfy predicate p. If every binding in m satisfies p, m is returned unchanged (the result of the function is then physically equal to m)
filter_map f m applies the function f to every binding of m, and builds a map from the results. For each binding (k, v) in the input map:
f k v is None then k is not in the result,f k v is Some v' then the binding (k, v') is in the output map.For example, the following function on maps whose values are lists
filter_map
(fun _k li -> match li with [] -> None | _::tl -> Some tl)
mdrops all bindings of m whose value is an empty list, and pops the first element of each value that is non-empty.
partition p m returns a pair of maps (m1, m2), where m1 contains all the bindings of m that satisfy the predicate p, and m2 is the map with all the bindings of m that do not satisfy p.
val cardinal : 'a t -> intReturn the number of bindings of a map.
Return the list of all bindings of the given map. The returned list is sorted in increasing order of keys with respect to the ordering Ord.compare, where Ord is the argument given to Map.Make.
Return the binding with the smallest key in a given map (with respect to the Ord.compare ordering), or raise Not_found if the map is empty.
Same as Map.S.min_binding, but returns the binding with the largest key in the given map.
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.
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.
find x m returns the current value of x in m, or raises Not_found if no binding for x exists.
find_last f m, where f is a monotonically decreasing function, returns the binding of m with the highest key k such that f k, or raises Not_found if no such key exists.
find_last_opt f m, where f is a monotonically decreasing function, returns an option containing the binding of m with the highest key k such that f k, or None if no such key exists.
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.
Same as Map.S.map, but the function receives as arguments both the key and the associated value for each binding of the map.
get k m returns Some v if the current binding of k in m is v, or None if the key k is not present. Safe version of find.
get_or k m ~default returns the value associated to k if present, and returns default otherwise (if k doesn't belong in m).
update k f m calls f (Some v) if find k m = v, otherwise it calls f None. In any case, if the result is None k is removed from m, and if the result is Some v' then add k v' m is returned.
choose_opt m returns one binding of the given map m, or None if m is empty. Safe version of choose.
min_binding_opt m returns the smallest binding of the given map m, or None if m is empty. Safe version of min_binding.
max_binding_opt m returns the largest binding of the given map m, or None if m is empty. Safe version of max_binding.
find_opt k m returns Some v if the current binding of k in m is v, or None if the key k is not present. Safe version of find.
find_first f m where f is a monotonically increasing function, returns the binding of m with the lowest key k such that f k, or raises Not_found if no such key exists. See Map.S.find_first.
find_first_opt f m where f is a monotonically increasing function, returns an option containing the binding of m with the lowest key k such that f k, or None if no such key exists. Safe version of find_first.
val merge_safe :
f:(key -> [ `Left of 'a | `Right of 'b | `Both of 'a * 'b ] -> 'c option) ->
'a t ->
'b t ->
'c tmerge_safe ~f a b merges the maps a and b together.
add_seq m seq adds the given Seq.t of bindings to the map m. Like add_list. Renamed from add_std_seq since 3.0.
add_seq ~f m l adds the given seq l of bindings to the map m, using f to combine values that have the same key. If a key occurs several times, all its bindings are combined using the function f, with f key v1 v2 being called with v1 occurring later in the seq than v2.
of_seq seq builds a map from the given Seq.t of bindings. Like of_list. Renamed from of_std_seq since 3.0.
of_seq_with ~f l builds a map from the given seq l of bindings k_i -> v_i, added in order using add. If a key occurs several times, all its bindings are combined using the function f, with f key v1 v2 being called with v1 occurring later in the seq than v2.
add_iter m iter adds the given iter of bindings to the map m. Like add_list.
add_iter ~f m l adds the given iter l of bindings to the map m, using f to combine values that have the same key. If a key occurs several times, all its bindings are combined using the function f, with f key v1 v2 being called with v1 occurring later in the seq than v2.
of_iter iter builds a map from the given iter of bindings. Like of_list.
of_iter_with ~f l builds a map from the given iter l of bindings k_i -> v_i, added in order using add. If a key occurs several times, all its bindings are combined using the function f, with f key v1 v2 being called with v1 occurring later in the iter than v2.
to_iter m iterates on the whole map m, creating an iter of bindings. Like to_list.
of_list l builds a map from the given list l of bindings k_i -> v_i, added in order using add. If a key occurs several times, only its last binding will be present in the result.
of_list_with ~f l builds a map from the given list l of bindings k_i -> v_i, added in order using add. If a key occurs several times, all its bindings are combined using the function f, with f key v1 v2 being called with v1 occurring later in the list than v2.
add_list m l adds the given list l of bindings to the map m.
add_list ~f m l adds the given list l of bindings to the map m, using f to combine values that have the same key. If a key occurs several times, all its bindings are combined using the function f, with f key v1 v2 being called with v1 occurring later in the seq than v2.
to_list m builds a list of the bindings of the given map m. The order is unspecified.