module Make:
Functor building an implementation of the map structure
given a totally ordered type.
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.
Before 4.03 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
).
Before 4.03 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
)
Before 4.03 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.