Module `BatMap`

module type S = sig ... end

Association tables over ordered types.

module Make (Ord : BatInterfaces.OrderedType) : S with type key = Ord.t

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

Common instantiations

module Int : S with type key = int

module Int32 : S with type key = int32

module Int64 : S with type key = int64

module Nativeint : S with type key = nativeint

module Float : S with type key = float

module Char : S with type key = char

module String : S with type key = string

Polymorphic maps

The functions below present the manipulation of polymorphic maps, as were provided by the Extlib PMap module.

They are similar in functionality to the functorized Make module, but only uses the Pervasives.compare function to compare elements. If you need to compare using a custom comparison function, it is recommended to use the functorized maps provided by Make.

type ('a, 'b) t

val empty : ('a, 'b) t

The empty map, using compare as key comparison function.

val is_empty : ('a, 'b) t -> bool

Returns true if the map is empty.

val singleton : 'a -> 'b -> ('a, 'b) t

Creates a new map with a single binding.

val cardinal : ('a, 'b) t -> int

Return the number of bindings of a map.

val add : 'a -> 'b -> ('a, 'b) t -> ('a, 'b) 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, its previous binding disappears.

val update : 'a -> 'a -> 'b -> ('a, 'b) t -> ('a, 'b) t

update k1 k2 v2 m replace the previous binding of k1 in m by k2 associated to v2. This is equivalent to add k2 v2 (remove k1) m, but more efficient in the case where k1 and k2 have the same key ordering.

raises Not_found
if k1 is not bound in m.

since 2.4.0

val find : 'a -> ('a, 'b) t -> 'b

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

val find_default : 'b -> 'a -> ('a, 'b) t -> 'b

find_default d x m returns the current binding of x in m, or the default value d if no such binding exists.

val remove : 'a -> ('a, 'b) t -> ('a, 'b) t

remove x m returns a map containing the same bindings as m, except for x which is unbound in the returned map.

val mem : 'a -> ('a, 'b) t -> bool

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

val iter : ('a -> 'b -> unit) -> ('a, 'b) 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 order in which the bindings are passed to f is unspecified. Only current bindings are presented to f: bindings hidden by more recent bindings are not passed to f.

val map : ('b -> 'c) -> ('a, 'b) t -> ('a, 'c) 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 order in which the associated values are passed to f is unspecified.

val mapi : ('a -> 'b -> 'c) -> ('a, 'b) t -> ('a, 'c) t

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

val fold : ('b -> 'c -> 'c) -> ('a, 'b) t -> 'c -> 'c

fold f m a computes (f kN dN ... (f k1 d1 (f k0 d0 a))...), where k0,k1..kN are the keys of all bindings in m, and d0,d1..dN are the associated data. The order in which the bindings are presented to f is unspecified.

val foldi : ('a -> 'b -> 'c -> 'c) -> ('a, 'b) t -> 'c -> 'c

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

val at_rank_exn : int -> ('key, 'a) t -> 'key * 'a

at_rank_exn i m returns the (key,value) pair whose key is at rank i in m, that is the i-th element in increasing order of the keys (the 0-th element being the smallest key in m with its associated value).

raises Not_found
if m = empty.

raises Invalid_argument
error_message if i < 0 || i >= cardinal m

since 2.4

val filterv : ('a -> bool) -> ('key, 'a) t -> ('key, 'a) t

filterv f m returns a map where only the values a of m such that f a = true remain. The bindings are passed to f in increasing order with respect to the ordering over the type of the keys.

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

filter f m returns a map where only the (key, value) pairs key, a of m such that f key a = true remain. The bindings are passed to f in increasing order with respect to the ordering over the type of the keys.

val filter_map : ('key -> 'a -> 'b option) -> ('key, 'a) t -> ('key, 'b) t

filter_map f m combines the features of filter and map. It calls calls f key0 a0, f key1 a1, f keyn an where a0..an are the elements of m and key0..keyn the respective corresponding keys. It returns the map of (keyi, bi) pairs such as f keyi ai = Some bi (when f returns None, the corresponding element of m is discarded).

val choose : ('key, 'a) t -> 'key * 'a

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

raises Not_found
if the map is empty

val any : ('key, 'a) t -> 'key * 'a

Return one binding of the given map. The difference with choose is that there is no guarantee that equals elements will be picked for equal sets. This merely returns the quickest binding to get (O(1)).

raises Not_found
if the map is empty.

val split : 'key -> ('key, 'a) t -> ('key, 'a) t * 'a option * ('key, '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.

val min_binding : ('key, 'a) t -> 'key * 'a

Returns the binding with the smallest key.

val pop_min_binding : ('key, 'a) t -> ('key * 'a) * ('key, 'a) t

Returns the binding with the smallest key along with the rest of the map.

val max_binding : ('key, 'a) t -> 'key * 'a

Returns the binding with the largest key.

val pop_max_binding : ('key, 'a) t -> ('key * 'a) * ('key, 'a) t

Returns the binding with the largest key along with the rest of the map.

val enum : ('a, 'b) t -> ('a * 'b) BatEnum.t

Creates an enumeration for this map, enumerating (key, value) pairs with the keys in increasing order.

val backwards : ('a, 'b) t -> ('a * 'b) BatEnum.t

Creates an enumeration for this map, enumerating (key, value) pairs with the keys in decreasing order.

val keys : ('a, 'b) t -> 'a BatEnum.t

Return an enumeration of all the keys of a map.

val values : ('a, 'b) t -> 'b BatEnum.t

Return an enumeration of all the values of a map.

val of_enum : ('a * 'b) BatEnum.t -> ('a, 'b) t

Creates a map from an enumeration.

val for_all : ('a -> 'b -> bool) -> ('a, 'b) t -> bool

Tests whether all (key, value) pairs satisfy a predicate function.

val exists : ('a -> 'b -> bool) -> ('a, 'b) t -> bool

Tests whether some (key, value) pair satisfies a predicate function.

val partition : ('a -> 'b -> bool) -> ('a, 'b) t -> ('a, 'b) t * ('a, 'b) 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.

val add_carry : 'a -> 'b -> ('a, 'b) t -> ('a, 'b) t * 'b option

add_carry k v m adds the binding (k, v) to m, returning the new map and optionally the previous value bound to k.

val modify : 'a -> ('b -> 'b) -> ('a, 'b) t -> ('a, 'b) t

modify k f m replaces the previous binding for k with f applied to that value. If k is unbound in m or Not_found is raised during the search, Not_found is raised.

since 1.2.0

raises Not_found
if k is unbound in m (or f raises Not_found)

val modify_def : 'b -> 'a -> ('b -> 'b) -> ('a, 'b) t -> ('a, 'b) t

modify_def v0 k f m replaces the previous binding for k with f applied to that value. If k is unbound in m or Not_found is raised during the search, f v0 is inserted (as if the value found were v0).

since 1.3.0

val modify_opt : 'a -> ('b option -> 'b option) -> ('a, 'b) t -> ('a, 'b) t

modify_opt k f m allow to modify the binding for k in m or absence thereof.

since 2.1

val extract : 'a -> ('a, 'b) t -> 'b * ('a, 'b) t

extract k m removes the current binding of k from m, returning the value k was bound to and the updated m.

val pop : ('a, 'b) t -> ('a * 'b) * ('a, 'b) t

pop m returns a binding from m and m without that binding.

val union : ('a, 'b) t -> ('a, 'b) t -> ('a, 'b) t

union m1 m2 merges two maps, using the comparison function of m1. In case of conflicted bindings, m2's bindings override m1's. Equivalent to foldi add m2 m1. The resulting map uses the comparison function of m1.

val diff : ('a, 'b) t -> ('a, 'b) t -> ('a, 'b) t

diff m1 m2 removes all bindings of keys found in m2 from m1, using the comparison function of m1. Equivalent to foldi (fun k _v m -> remove k m) m2 m1. The resulting map uses the comparison function of m1.

val intersect : ('b -> 'c -> 'd) -> ('a, 'b) t -> ('a, 'c) t -> ('a, 'd) t

intersect merge_f m1 m2 returns a map with bindings only for keys bound in both m1 and m2, and with k bound to merge_f v1 v2, where v1 and v2 are k's bindings in m1 and m2. The resulting map uses the comparison function of m1.

val merge : 
  ('key -> 'a option -> 'b option -> 'c option) ->
  ('key, 'a) t ->
  ('key, 'b) t ->
  ('key, '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. The resulting map uses the comparison function of m1.

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

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

Construct a comparison or equality function for maps based on a value comparison or equality function. Uses the key comparison function to compare keys

module Exceptionless : sig ... end

Exceptionless versions of functions

module Infix : sig ... end

Infix operators over a BatPMap

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

Map find and insert from Infix

val (<--) : ('a, 'b) t -> ('a * 'b) -> ('a, 'b) t

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

Return the list of all bindings of the given map. The returned list is sorted in increasing key order.

Added for compatibility with stdlib 3.12

Boilerplate code

Printing

val print : 
  ?first:string ->
  ?last:string ->
  ?sep:string ->
  ?kvsep:string ->
  ('a BatInnerIO.output -> 'b -> unit) ->
  ('a BatInnerIO.output -> 'c -> unit) ->
  'a BatInnerIO.output ->
  ('b, 'c) t ->
  unit

module PMap : sig ... end

Install

Dune Dependency

Authors

Maintainers

Sources

doc/batteries/BatMap/index.html

Module `BatMap`

Common instantiations

Polymorphic maps

Boilerplate code

Printing

package batteries

Install

Dune Dependency

Authors

Maintainers

Sources

doc/batteries/BatMap/index.html

Module BatMap

Common instantiations

Polymorphic maps

Boilerplate code

Printing

Module `BatMap`