28: Properties - royal-lang/rl GitHub Wiki

Royal supports properties which are similar to variables except for that they wrap around a getter-function and a setter-function.

Properties are declared using the prop keyword.

prop NAME
{
    get { GET_EXPRESSION };
    set{ SET_EXPRESSION };
    set (valueName) { SET_EXPRESSION };
}

If no valueName is specified then the name of value will default to value.

Both the get and set expressions are optional but one of them must be present.

A property with both the get and set without any expressions but declared will be the same as a variable. These can be used to trigger invariants etc.

A property can also have a single variable declared within its scope which can only be accessed by its getter or setter.

Example:

private:
var string _name;
public:
prop string name
{
    get { return _name; }
    set
    {
        _name = newName;
    }
}

prop string name
{
    var string _name;

    get { return _name; }
    set
    {
        _name = value;
    }
}

prop string name
{
    var string _name;

    get { return _name; }
    set (newName)
    {
        _name = newName;
    }
}

prop string name { get; set; }