Counting

NOTE: following API is work in progress. You can try it by source checkout

Count class is used for counting by Units.

Let us see how to use it:

import jlibs.core.lang;

// we want to count the time
Count<DurationUnit> duration = Count.newInstance(DurationUnit.class);

// additions
duration.add(500, DurationUnit.SECONDS);
System.out.println(duration); // prints "8 MINUTES 20 SECONDS"
duration.add(100, DurationUnit.MINUTES);
System.out.println(duration); // prints "1 HOURS 48 MINUTES 20 SECONDS"

// get specific unit value
System.out.println(duration.get(DurationUnit.MINUTES); // prints "48"
System.out.println(duration.get(DurationUnit.SECONDS); // prints "20"

// conversions
System.out.println(duration.to(DurationUnit.SECONDS)); // prints "6500.0"
System.out.println(duration.to(DurationUnit.MINUTES)); // prints "108.33333333333333"

// reset to given value
duration.set(500, DurationUnit.SECONDS);
System.out.println(duration); // prints "8 MINUTES 20 SECONDS"

// reset to 0
duration.clear();
System.out.println(duration); // prints "0 NANO_SECONDS"

// adding two counts
Count<DurationUnit> duration1 = Count.newInstance(DurationUnit.class);
duration1.add(500, DurationUnit.SECONDS);
Count<DurationUnit> duration2 = Count.newInstance(DurationUnit.class);
duration2.add(100, DurationUnit.MINUTES);
duration1.add(duration2);
System.out.println(duration1); // prints "1 HOURS 48 MINUTES 20 SECONDS"

// you can count by any unit, for example
Count<SizeUnit> size = Count.newInstance(SizeUnit.class);
size.add(5000, SizeUnit.BYTES);
System.out.println(size); // prints "4 KB 904 BYTES"

You can count by any unit, by providing its definition.
JLibs comes with two units DurationUnit and SizeUnit.

Let us see how to define LengthUnit:

public enum LengthUnit implements Count.Unit{

    MILLI_METERS(10), CENTI_METERS(100), METERS(1000), KILO_METERS(0);



    private int count;



    private DurationUnit(int count){

        this.count = count;

    }



    @Override

    public int count(){

        return count;

    }

}

we define an enum implementing Count.Unit interface.
The enum constants are ordered from lowest to highest.
for each enum provide the count to promote to next enum.
for example: MILLI_METERS(10) means, 10 millimeters should be promoted to 1 centimeter.

now we are ready to count length:

Count<LengthUnit> size = Count.newInstance(LengthUnit.class);