Module Counter (.ml)

module Counter: sig .. end

int counter

a counter for non-negative numbers.

Types

type counter

exception OVERFLOW

raised if the counter is exhausted.

Functions

val create : unit -> counter

creates a fresh counter initialized with 0.

val create_with : int -> counter

create_with start_value creates a new counter with start_value. start_value must be >= 0.

val set : counter -> int -> unit

set value sets the counter to value. value must be >= 0.

val inc : counter -> unit

increments the counter by 1.
Raises OVERFLOW on overflow.

val inc_by : counter -> int -> unit

increments the counter by the given positive value.
Raises OVERFLOW on overflow.

val dec : counter -> unit

decrements the counter by 1.
Raises OVERFLOW if the counter drops below 0.

val next : counter -> int

increments the counter by 1 and returns its new value. Note: this implies that 0 is never returned as a counter value.
Raises OVERFLOW on overflow.

val value : counter -> int

returns the current value of the counter.