while

Arguments: condition &rest forms

Evaluates forms repeatedly until condition (which should be a Lisp form) evaluates to nil.

The definition of while is

(defmacro while (condition &rest forms)
  `(loop (unless ,condition (return)) ,@forms))

Note that loop surrounds its body with a block named nil (as used by the return form which is the consequent of the unless form). This macro returns nil.

See also until.

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Created 2010.1.21.