rex (language)
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This article is about a functional programming language used primarily by students. For the scripting language created by IBM, see REXX.
rex is a functional programming language developed by Robert M. Keller for use in teaching functional programming to Harvey Mudd College students.
[edit] Example
The "Hello World" of functional languages is the factorial function. Expressed in rex:
factorial(0) => 1; factorial(X) => X * factorial(X-1);
The name "rex" derives from "rewriting expressions", which is the basic principle underlying the implementation: replace an instantiation of an expression on the left-hand side of a rule with the instantiated right-hand side.
