LinearizedArray.mli 1.22 KB
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(* An array of arrays (of possibly different lengths!) can be ``linearized'',
   i.e., encoded as a data array (by concatenating all of the little arrays)
   and an entry array (which contains offsets into the data array). *)

type 'a t =
  (* data: *)   'a array *
  (* entry: *) int array

(* [make a] turns the array of arrays [a] into a linearized array. *)

val make: 'a array array -> 'a t

(* [read la i j] reads the linearized array [la] at indices [i] and [j].
   Thus, [read (make a) i j] is equivalent to [a.(i).(j)]. *)

val read: 'a t -> int -> int -> 'a

(* [write la i j v] writes the value [v] into the linearized array [la]
   at indices [i] and [j]. *)

val write: 'a t -> int -> int -> 'a -> unit

(* [length la] is the number of rows of the array [la]. Thus, [length (make
   a)] is equivalent to [Array.length a]. *)

val length: 'a t -> int

(* [row_length la i] is the length of the row at index [i] in the linearized
   array [la]. Thus, [row_length (make a) i] is equivalent to [Array.length
   a.(i)]. *)

val row_length: 'a t -> int -> int

(* [read_row la i] reads the row at index [i], producing a list. Thus,
   [read_row (make a) i] is equivalent to [Array.to_list a.(i)]. *)

val read_row: 'a t -> int -> 'a list