References

In the Ryna type system, references are the way the language has to make indirect value assotiations. They can be seen as analogous to pointers in languages such as C or C++, but are much safer, since you generally cannot access invalid data.

There are two kinds of references in the Ryna type system:

• Constant references: they can be used to read the data that they point to, but you cannot modify it under any circumstances.
• Mutable references: The same as constant ones, but you are allowed to modify or even replace the underlying data.

Now, in order to pointt to something, you need to know what you are pointing to. This is done with other types. When you want to create a constant reference that points to a value of type T, you use the type &T. In a similar way, you use @T for a mutable reference pointing to a T. You can also construct chained references such as @&T.

Using this rule, we could construct types such as &Int or @String, which refer to a constant reference to an Int and a mutable reference to a String, respectively. In the next sections we will see how to create even more complex types.