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Predicate Arguments

A predicate allows for checking for valid values. These arguments are dedicated to checking whether some sort of value is valid according to user input.

Double range argument​

This argument can be used as a predicate for numbers, which require precise input.

Example usage​

public static LiteralCommandNode<CommandSourceStack> doubleRange() {
    return Commands.literal("doublerange")
        .then(Commands.argument("arg", ArgumentTypes.doubleRange())
            .executes(ctx -> {
                final DoubleRangeProvider doubleRangeProvider = ctx.getArgument("arg", DoubleRangeProvider.class);
                final CommandSender sender = ctx.getSource().getSender();

                for (int i = 0; i < 5; i++) {
                    sender.sendRichMessage("Is <index> in bounds? <result>",
                        Placeholder.unparsed("index", Integer.toString(i)),
                        Placeholder.unparsed("result", Boolean.toString(doubleRangeProvider.range().test((double) i)))
                    );
                }
                return Command.SINGLE_SUCCESS;
            }))
        .build();
}

In-game preview​

Integer range argument​

This argument works very similarly to the double range argument, with the only difference being that this argument only accepts integers.

Example usage​

MinecraftArguments.java
public static LiteralCommandNode<CommandSourceStack> integerRangeArgument() {
    return Commands.literal("integerrange")
        .then(Commands.argument("range", ArgumentTypes.integerRange())
            .then(Commands.argument("tested_integer", IntegerArgumentType.integer())
                .executes(MinecraftArguments::runIntegerRangeCommand)))
        .build();
}

private static int runIntegerRangeCommand(final CommandContext<CommandSourceStack> ctx) {
    final IntegerRangeProvider integerRangeProvider = ctx.getArgument("range", IntegerRangeProvider.class);
    final int integerToTest = ctx.getArgument("tested_integer", int.class);

    if (integerRangeProvider.range().contains(integerToTest)) {
        ctx.getSource().getSender().sendRichMessage("<aqua><input></aqua> <green>is</green> inside the specified range!",
            Placeholder.unparsed("input", Integer.toString(integerToTest))
        );
        return Command.SINGLE_SUCCESS;
    }

    ctx.getSource().getSender().sendRichMessage("<aqua><input></aqua> <red>is not</red> inside the specified range!",
        Placeholder.unparsed("input", Integer.toString(integerToTest))
    );

    return Command.SINGLE_SUCCESS;
}

In-game preview​

Item predicate argument​

This argument allows for checking whether an item fits some predicate. It is useful for filtering out certain items based on some criteria.

Example usage​

public static LiteralCommandNode<CommandSourceStack> itemPredicateArgument() {
    return Commands.literal("itempredicate")
        .then(Commands.argument("predicate", ArgumentTypes.itemPredicate())
            .executes(ctx -> {
                final ItemStackPredicate predicate = ctx.getArgument("predicate", ItemStackPredicate.class);
                final ItemStack defaultWoodenSword = ItemType.WOODEN_SWORD.createItemStack();

                ctx.getSource().getSender().sendRichMessage("Is default wooden sword? <result>.",
                    Placeholder.parsed("result", predicate.test(defaultWoodenSword) ? "<green>true" : "<red>false")
                );
                return Command.SINGLE_SUCCESS;
            }))
        .build();
}

In-game preview​