common-lisp Getting started with common-lisp The simple Hello World program in REPL
Example
Common Lisp REPL is an interactive environment. Every form written after the prompt is evaluated, and its value is afterwards printed as result of the evaluation. So the simplest possible “Hello, World!” program in Common Lisp is:
CL-USER> "Hello, World!"
"Hello, World!"
CL-USER>
What happens here is that a string costant is given in input to the REPL, it is evaluated and the result is printed. What can be seen from this example is that strings, like numbers, special symbols like NIL and T and a few other literals, are self-evaluating forms: that is they evaluate to themselves.
