Arguments

An argument is a descriptor for a kind of value that the user can provide to the command. For example, in the command git commit -m "Hello World", the argument is -m and it's value is "Hello World". It provides a way for the user to provide input to the command.

Defining Arguments

We are going to make an argument that takes an integer as input. We will call it number.

Using Argument Templates

Add a new property to your command template class, and annotate it with @Argument.Define.

@Command.Define
class MyCommand extends CommandTemplate {
	@Argument.Define
	public int number;
}

Defining Arguments Imperatively

Add arguments to a command by using the Command#addArgument method:

var myCommand = new ArgumentParser("MyCommand") {{
	addArgument(Argument.create(new IntegerArgumentType(), "number"));
}};

Lanat will create an argument called number which will have an IntegerArgumentType as its type. This means that the user will have to provide a valid integer value as input for this argument.

Notice how we never had to explicitly specify the type of the argument. Lanat can infer the type of the argument from the type of the property that it is assigned to.

We'll take a deeper look at argument types later on.

Last modified: 23 April 2024