language, LISP, programming
(REPL) A programming structure within LISP which repeatedly reads a form from the user, evaluates it, and displays the result.
A read-eval-print loop forms the basis of the Top-Level shell that programmers of the LISP family of languages interact with.
In many dialects of LISP a very simple REPL could be implemented as:
(loop (print (eval (read)))).