The script language is expression-based. The script environment just evaluates an expression one by one and passes the last result to the Java environment. So scripts are evaluated interactively by the script interpreter. Pnuts integrates these data types so that the User does not have to care about the difference between them. Primitive data is automatically converted to a wrapper class such as java.lang.Integer.
Arithmetic operations take such wrapper objects for their calculations.
In addition, multi-precision number which is provided by java.math package in JDK1.1 can be used transparently. Pseudo List Pnuts has list notation which is a common feature of other languages such as Lisp and it's dialects. Actually, pseudo list is implemented as an array of objects. It means that it is simply a syntax sugar. But pseudo list can simplify the code, especially for nested array, so it encourages the User to use object arrays for their programs.