Module CCArrayLabelsSource

Fast internal iterator.

• since 2.8

empty is the empty array, physically equal to [||].

equal eq a1 a2 is true if the lengths of a1 and a2 are the same and if their corresponding elements test equal, using eq.

compare cmp a1 a2 compares arrays a1 and a2 using the function comparison cmp.

swap a i j swaps elements at indices i and j.

• since 1.4

get_safe a i returns Some a.(i) if i is a valid index.

• since 0.18

map_inplace ~f a replace all elements of a by its image by f.

• since 3.8

mapi_inplace ~f a replace all elements of a by its image by f.

• since 3.10

fold ~f ~init a computes f (… (f (f init a.(0)) a.(1)) …) a.(n-1), where n is the length of the array a. Same as ArrayLabels.fold_left

foldi ~f ~init a is just like fold, but it also passes in the index of each element as the second argument to the folded function f.

fold_while ~f ~init a folds left on array a until a stop condition via ('a, `Stop) is indicated by the accumulator.

• since 0.8

fold_map ~f ~init a is a fold_left-like function, but it also maps the array to another array.

• since 1.2, but only

• since 2.1 with labels

scan_left ~f ~init a returns the array [|init; f init x0; f (f init a.(0)) a.(1); …|] .

• since 1.2, but only

• since 2.1 with labels

reverse_in_place a reverses the array a in place.

sorted ~f a makes a copy of a and sorts it with f.

• since 1.0

sort_indices ~f a returns a new array b, with the same length as a, such that b.(i) is the index at which the i-th element of sorted f a appears in a. a is not modified.

In other words, map (fun i -> a.(i)) (sort_indices f a) = sorted f a. sort_indices yields the inverse permutation of sort_ranking.

• since 1.0

sort_ranking ~f a returns a new array b, with the same length as a, such that b.(i) is the index at which the i-th element of a appears in sorted f a. a is not modified.

In other words, map (fun i -> (sorted f a).(i)) (sort_ranking f a) = a. sort_ranking yields the inverse permutation of sort_indices.

In the absence of duplicate elements in a, we also have lookup_exn a.(i) (sorted a) = (sorted_ranking a).(i).

• since 1.0

mem ~eq x a return true if x is present in a. Linear time.

• since 3.0

find_map ~f a returns Some y if there is an element x such that f x = Some y. Otherwise returns None.

• since 1.3, but only

• since 2.1 with labels

find_map_i ~f a is like find_map, but the index of the element is also passed to the predicate function f.

• since 1.3, but only

• since 2.1 with labels

find_idx ~f a returns Some (i,x) where x is the i-th element of a, and f x holds. Otherwise returns None.

• since 0.3.4

max ~cmp a returns None if a is empty, otherwise, returns Some e where e is a maximum element in a with respect to cmp.

• since 3.12

max_exn ~cmp a is like max, but

• raises Invalid_argument

  if a is empty.

• since 3.12

argmax ~cmp a returns None if a is empty, otherwise, returns Some i where i is the index of a maximum element in a with respect to cmp.

• since 3.12

argmax_exn ~cmp a is like argmax, but

• raises Invalid_argument

  if a is empty.

• since 3.12

min ~cmp a returns None if a is empty, otherwise, returns Some e where e is a minimum element in a with respect to cmp.

• since 3.12

min_exn ~cmp a is like min, but

• raises Invalid_argument

  if a is empty.

• since 3.12

argmin ~cmp a returns None if a is empty, otherwise, returns Some i where i is the index of a minimum element in a with respect to cmp.

• since 3.12

argmin_exn ~cmp a is like argmin, but

• raises Invalid_argument

  if a is empty.

• since 3.12

lookup ~cmp ~key a lookups the index of some key key in a sorted array a. Undefined behavior if the array a is not sorted wrt cmp. Complexity: O(log (n)) (dichotomic search).

• returns

  None if the key key is not present, or Some i (i the index of the key) otherwise.

lookup_exn ~cmp ~key a is like lookup, but

• raises Not_found

  if the key key is not present.

bsearch ~cmp ~key a finds the index of the object key in the array a, provided a is sorted using cmp. If the array is not sorted, the result is not specified (may raise Invalid_argument).

Complexity: O(log n) where n is the length of the array a (dichotomic search).

• returns
  • `At i if cmp a.(i) key = 0 (for some i).
  • `All_lower if all elements of a are lower than key.
  • `All_bigger if all elements of a are bigger than key.
  • `Just_after i if a.(i) < key < a.(i+1).
  • `Empty if the array a is empty.

• raises Invalid_argument

  if the array is found to be unsorted w.r.t cmp.

• since 0.13

for_all2 ~f [|a1; …; an|] [|b1; …; bn|] is true if each pair of elements ai bi satisfies the predicate f. That is, it returns (f a1 b1) && (f a2 b2) && … && (f an bn).

• raises Invalid_argument

  if arrays have distinct lengths. Allow different types.

• since 0.20

exists2 ~f [|a1; …; an|] [|b1; …; bn|] is true if any pair of elements ai bi satisfies the predicate f. That is, it returns (f a1 b1) || (f a2 b2) || … || (f an bn).

• raises Invalid_argument

  if arrays have distinct lengths. Allow different types.

• since 0.20

fold2 ~f ~init a b fold on two arrays a and b stepwise. It computes f (… (f init a1 b1) …) an bn.

• raises Invalid_argument

  if a and b have distinct lengths.

• since 0.20

shuffle a randomly shuffles the array a, in place.

shuffle_with rs a randomly shuffles the array a (like shuffle) but a specialized random state rs is used to control the random numbers being produced during shuffling (for reproducibility).

random_choose a rs randomly chooses an element of a.

• raises Not_found

  if the array/slice is empty.

to_string ~sep item_to_string a print a to a string using sep as a separator between elements of a.

• since 2.7

to_iter a returns an iter of the elements of an array a. The input array a is shared with the sequence and modification of it will result in modification of the iterator.

• since 2.8

to_gen a returns a gen of the elements of an array a.

pp ~pp_start ~pp_stop ~pp_sep pp_item ppf a formats the array a on ppf. Each element is formatted with pp_item, pp_start is called at the beginning, pp_stop is called at the end, pp_sep is called between each elements. By defaults pp_start and pp_stop does nothing and pp_sep defaults to (fun out -> Format.fprintf out ",@ ").

pp_i ~pp_start ~pp_stop ~pp_sep pp_item ppf a prints the array a on ppf. The printing function pp_item is giving both index and element. pp_start is called at the beginning, pp_stop is called at the end, pp_sep is called between each elements. By defaults pp_start and pp_stop does nothing and pp_sep defaults to (fun out -> Format.fprintf out ",@ ").

rev a copies the array a and reverses it in place.

• since 0.20

filter ~f a filters elements out of the array a. Only the elements satisfying the given predicate f will be kept.

filter_map ~f [|a1; …; an|] calls (f a1) … (f an) and returns an array b consisting of all elements bi such as f ai = Some bi. When f returns None, the corresponding element of a is discarded.

monoid_product ~f a b passes all combinaisons of tuples from the two arrays a and b to the function f.

• since 2.8

flat_map ~f a transforms each element of a into an array, then flattens.

except_idx a i removes the element of a at given index i, and returns the list of the other elements.

sort_generic (module M) ~cmp a sorts the array a, without allocating (eats stack space though). Performance might be lower than Array.sort.

• since 0.14