plucky (3) Misc.Stdlib.String.Map.3o.gz
NAME
Misc.Stdlib.String.Map - no description
Module
Module Misc.Stdlib.String.Map
Documentation
Module Map
: sig end
Maps
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 add : key -> 'a -> 'a t -> 'a t
add key data m returns a map containing the same bindings as m , plus a binding of key to data . If key
was already bound in m to a value that is physically equal to data , m is returned unchanged (the result
of the function is then physically equal to m ). Otherwise, the previous binding of key in m disappears.
Before4.03 Physical equality was not ensured.
val add_to_list : key -> 'a -> 'a list t -> 'a list t
add_to_list key data m is m with key mapped to l such that l is data :: Map.find key m if key was bound
in m and [v] otherwise.
Since 5.1
val update : key -> ('a option -> 'a option) -> 'a t -> 'a t
update key f m returns a map containing the same bindings as m , except for the binding of key .
Depending on the value of y where y is f (find_opt key m) , the binding of key is added, removed or
updated. If y is None , the binding is removed if it exists; otherwise, if y is Some z then key is
associated to z in the resulting map. If key was already bound in m to a value that is physically equal
to z , m is returned unchanged (the result of the function is then physically equal to m ).
Since 4.06
val singleton : key -> 'a -> 'a t
singleton x y returns the one-element map that contains a binding y for x .
Since 3.12
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 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 .
Since 3.12
val union : (key -> 'a -> 'a -> 'a option) -> 'a t -> 'a t -> 'a t
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 = None
- f' _key (Some v) None = Some v
- f' _key None (Some v) = Some v
- f' key (Some v1) (Some v2) = f key v1 v2
Since 4.03
val cardinal : 'a t -> int
Return the number of bindings of a map.
Since 3.12
Bindings
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 of
keys with respect to the ordering Ord.compare , where Ord is the argument given to Map.Make .
Since 3.12
val min_binding : 'a t -> key * 'a
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.
Since 3.12
val min_binding_opt : 'a t -> (key * 'a) option
Return the binding with the smallest key in the given map (with respect to the Ord.compare ordering), or
None if the map is empty.
Since 4.05
val max_binding : 'a t -> key * 'a
Same as Map.S.min_binding , but returns the binding with the largest key in the given map.
Since 3.12
val max_binding_opt : 'a t -> (key * 'a) option
Same as Map.S.min_binding_opt , but returns the binding with the largest key in the given map.
Since 4.05
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
val choose_opt : 'a t -> (key * 'a) option
Return one binding of the given map, or None if the map is empty. Which binding is chosen is unspecified,
but equal bindings will be chosen for equal maps.
Since 4.05
Searching
val find : key -> 'a t -> 'a
find x m returns the current value of x in m , or raises Not_found if no binding for x exists.
val find_opt : key -> 'a t -> 'a option
find_opt x m returns Some v if the current value of x in m is v , or None if no binding for x exists.
Since 4.05
val find_first : (key -> bool) -> 'a t -> key * 'a
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.
For example, find_first (fun k -> Ord.compare k x >= 0) m will return the first binding k, v of m where
Ord.compare k x >= 0 (intuitively: k >= x ), or raise Not_found if x is greater than any element of m .
Since 4.05
val find_first_opt : (key -> bool) -> 'a t -> (key * 'a) option
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.
Since 4.05
val find_last : (key -> bool) -> 'a t -> key * 'a
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.
Since 4.05
val find_last_opt : (key -> bool) -> 'a t -> (key * 'a) option
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.
Since 4.05
Traversing
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 -> 'acc -> 'acc) -> 'a t -> 'acc -> 'acc
fold f m init computes (f kN dN ... (f k1 d1 init)...) , where k1 ... kN are the keys of all bindings in
m (in increasing order), and d1 ... dN are the associated data.
Transforming
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.
val filter : (key -> 'a -> bool) -> 'a t -> 'a t
filter f m returns the map with all the bindings in m that satisfy predicate p . If every binding in m
satisfies f , 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
val filter_map : (key -> 'a -> 'b option) -> 'a t -> 'b t
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:
-if f k v is None then k is not in the result,
-if 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)
m
drops all bindings of m whose value is an empty list, and pops the first element of each value that is
non-empty.
Since 4.11
val partition : (key -> 'a -> bool) -> 'a t -> 'a t * 'a t
partition f m returns a pair of maps (m1, m2) , where m1 contains all the bindings of m that satisfy the
predicate f , and m2 is the map with all the bindings of m that do not satisfy f .
Since 3.12
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
Predicates and comparisons
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 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 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 for_all : (key -> 'a -> bool) -> 'a t -> bool
for_all f m checks if all the bindings of the map satisfy the predicate f .
Since 3.12
val exists : (key -> 'a -> bool) -> 'a t -> bool
exists f m checks if at least one binding of the map satisfies the predicate f .
Since 3.12
Converting
val to_list : 'a t -> (key * 'a) list
to_list m is Map.S.bindings m .
Since 5.1
val of_list : (key * 'a) list -> 'a t
of_list bs adds the bindings of bs to the empty map, in list order (if a key is bound twice in bs the
last one takes over).
Since 5.1
val to_seq : 'a t -> (key * 'a) Seq.t
Iterate on the whole map, in ascending order of keys
Since 4.07
val to_rev_seq : 'a t -> (key * 'a) Seq.t
Iterate on the whole map, in descending order of keys
Since 4.12
val to_seq_from : key -> 'a t -> (key * 'a) Seq.t
to_seq_from k m iterates on a subset of the bindings of m , in ascending order of keys, from key k or
above.
Since 4.07
val add_seq : (key * 'a) Seq.t -> 'a t -> 'a t
Add the given bindings to the map, in order.
Since 4.07
val of_seq : (key * 'a) Seq.t -> 'a t
Build a map from the given bindings
Since 4.07