From 5614b2edd67e522764ebe063a751e5eedeb7ee5d Mon Sep 17 00:00:00 2001 From: Marco Baringer Date: Thu, 26 Jan 2006 13:09:47 +0100 Subject: [PATCH] Allow for-all bindings to be lists used with destructuring-bind --- src/random.lisp | 66 +++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 57 insertions(+), 9 deletions(-) diff --git a/src/random.lisp b/src/random.lisp index a1f16bb..f2d8a0a 100644 --- a/src/random.lisp +++ b/src/random.lisp @@ -14,6 +14,16 @@ ;;;; failure we stop running and report what values of the variables ;;;; caused the code to fail. +;;;; The generation of the random data is done using "generator +;;;; functions" (see below for details). A generator function is a +;;;; function which creates, based on user supplied parameters, a +;;;; function which returns random data. In order to facilitate +;;;; generating good random data the FOR-ALL macro also supports guard +;;;; conditions and creating one random input based on the values of +;;;; another (see the FOR-ALL macro for details). + +;;;; *** Public Interface to the Random Tester + (defparameter *num-trials* 100 "Number of times we attempt to run the body of the FOR-ALL test.") @@ -27,13 +37,51 @@ where the test code is never run due to the guards never returning true. This second run limit prevents that.") (defmacro for-all (bindings &body body) - `(perform-random-testing - (list ,@(mapcar #'second bindings)) - (lambda ,(mapcar #'first bindings) - (if (and ,@(delete-if #'null (mapcar #'third bindings))) - (progn ,@body) - (throw 'run-once - (list :guard-conditions-failed)))))) + "Bind BINDINGS to random variables and test BODY *num-trials* times. + +BINDINGS is a list of binding forms, each element is a list +of (BINDING VALUE &optional GUARD). Value, which is evaluated +once when the for-all is evaluated, must return a generator which +be called each time BODY is evaluated. BINDING is either a symbol +or a list which will be passed to destructuring-bind. GUARD is a +form which, if present, stops BODY from executing when IT returns +NIL. The GUARDS are evaluated after all the random data has been +generated and they can refer to the current value of any +binding. NB: Generator forms, unlike guard forms, can not contain +references to the boud variables. + +Examples: + + (for-all ((a (gen-integer))) + (is (integerp a))) + + (for-all ((a (gen-integer) (plusp a))) + (is (integerp a)) + (is (plusp a))) + + (for-all ((less (gen-integer)) + (more (gen-integer) (< less more))) + (is (<= less more))) + + (for-all (((a b) (gen-two-integers))) + (is (integerp a)) + (is (integerp b)))" + (with-unique-names (test-lambda-args) + `(perform-random-testing + (list ,@(mapcar #'second bindings)) + (lambda (,test-lambda-args) + (destructuring-bind ,(mapcar #'first bindings) + ,test-lambda-args + (if (and ,@(delete-if #'null (mapcar #'third bindings))) + (progn ,@body) + (throw 'run-once + (list :guard-conditions-failed)))))))) + +;;;; *** Implementation + +;;;; We could just make FOR-ALL a monster macro, but having FOR-ALL be +;;;; a preproccessor for the perform-random-testing function is +;;;; actually much easier. (defun perform-random-testing (generators body) (loop @@ -72,7 +120,7 @@ returning true. This second run limit prevents that.") (catch 'run-once (bind-run-state ((result-list '())) (let ((values (mapcar #'funcall generators))) - (apply body values) + (funcall body values) (cond ((null result-list) (throw 'run-once (list :no-tests))) @@ -113,7 +161,7 @@ returning true. This second run limit prevents that.") ;;;; We provide a set of built-in generators. (defun gen-integer (&key (max (1+ most-positive-fixnum)) - (min (1- most-negative-fixnum))) + (min (1- most-negative-fixnum))) "Returns a generator which produces random integers greater than or equal to MIN and less than or equal to MIN." (lambda () -- 1.7.10.4