2.4 Data Declarations

In fact, T3X is not a totally typeless language. It is called a 'typeless' language anyway, because even BCPL (which pushes the typeless concept quite to its limit) has at least two types (variables and MANIFEST constants) which require different handling at compile time. In T3X, the following types exist:

• Atomic variables
• Constants
• Vectors
• Structures
• Procedures
• Methods
• Objects

Vectors and structures are basically the same and there is no big difference between methods and procedures, either. Atomic variables are used to hold small numeric values or single ASCII characters (which are represented by numbers). Constants are used to provide symbolic names for immutable numeric values. Vectors are sequences of atomic variables. A structure is a set of constants which is used to give names to specific members of a vector. Procedures process parameters and return values just like mathematical functions. Since T3X is an imperative language, they usually have side effects, too. A method is a procedure which is used to alter the state of an object. An object is an instance of a class (which is not a type of its own). Classes will be discussed in detail in the section about the T3X object model.