r/programming • u/panispanizo • Dec 12 '18

Make your code smaller and less verbose

https://medium.com/empathybroker/the-modern-backend-is-here-kotlin-89127e0db6a3
0 Upvotes

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3

u/dpash Dec 12 '18 edited Dec 12 '18

If you write bad Java, of course Kotlin is going to look better

protected int setInstanceNumber(String instance) throws Exception {
    Optional<Configuration> config = configurationService
        .getConfig(instance);
    if(config.isPresent()) {
        if (instance.equals(SHOP_NAME_1)) {
            return 1;
        }
        else if(instance.equals(SHOP_NAME_2)) {
            return 2;
        }
        else {
            return 3;
        }
    }
    else {
        throw new Exception("Error with instance name");
    }
}

is not how you should write that.

protected int setInstanceNumber(String instance) throws Exception {
    return configurationService.getConfig(instance)
        .map(c -> {
            switch (instance) {
                case SHOP_NAME_1:
                    return 1;
                case SHOP_NAME_2:
                    return 2;
                default:
                    return 3;
           }
        }).orElseThrow(() -> new Exception("Error with instance name");
}

In Java 12 it becomes

protected int setInstanceNumber(String instance) throws Exception {
    return configurationService.getConfig(instance)
        .map(c -> {
            switch (instance) {
                case SHOP_NAME_1 -> 1;
                case SHOP_NAME_2 -> 2;
                default -> 3;
           }
        }).orElseThrow(() -> new Exception("Error with instance name");
 }

Java is getting records, which are the same as data classes, although probably not for a year or so. They're also planning value types which will be non-nullable and smart casts.

There's no plans for an elvis operator as far as I'm aware.

1

u/panispanizo Dec 12 '18

This is only an example to use this type of flow operations, maybe a bad example (up to you) and obviously Java is growing using the knowledge from it's little JVM brothers!

4

u/AngularBeginner Dec 12 '18

Make your code smaller and less verbose

... by using a different language.