Omitted Features

Perhaps as important as what to include is what not to include. For example, Nickle contains no Object-Oriented Programming (OOP) features. Class-based OOP in the style of C++ and Java is well understood and accepted. However, the combination of this style of OOP with some of the current and proposed features of Nickle, especially polymorphic type inference and first-class functions and continuations, verges on open research questions. In addition, the most useful domains of application of OOP, such as large-scale programming, easy reuse of opaque constructs, and graphics and window system programming, are outside the intended scope of Nickle's applicability.

Other features deliberately omitted from Nickle include:

• Support for graphics and GUI implementation. The impact of this support on the portability and simplicity of the Nickle implementation is potentially large, and the perceived benefit for expected Nickle applications is presently small. Nonetheless, this decision may be revisited in the future.
• Language-level support for interfacing with native code. In actuality, as discussed below, it is quite easy to integrate native code with Nickle programs, but only by integrating the native code into the Nickle implementation.
• Ad-hoc polymorphism, operator overloading, user-defined operators, and related features. This is driven by concern about the complexity and difficulty of implementation of these features, and their perceived negative impact on readability and portability of code. The general philosophy of Nickle is that anything important enough to require these features is important enough to embed in the language definition.