Functional Counters

Denys Duchier

module

x-oz://system/adt/Counter.ozf

This module provides a functional interface for counters

Exports

The modules exports 2 constructors:

{Counter.newFromInt +I ?C}

returns a new functional counter instance, initialized to integer value I

{Counter.new ?C}

return a new functional counter instance, initialized to 1

Instance API

Each functional counter instance C has the following features:

{C.get ?I}

returns the current value I of C

{C.put +I}

sets the current value of C to I

{C.getPut Old New}

atomically gets the current value Old of C and sets it to the new value New

{C.next ?I}

returns the current value I of C and increments the counter

{C.plus +N}

increments C by N

{C.times +N}

multiplies the content of C by N

{C.clone ?C2}

returns a new counter C2 currently holding the same integer value as C