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;; Copyright (c) Stephen C. Gilardi. All rights reserved. The use and
;; distribution terms for this software are covered by the Common Public
;; License 1.0 (http://opensource.org/licenses/cpl.php) which can be found
;; in the file CPL.TXT at the root of this distribution. By using this
;; software in any fashion, you are agreeing to be bound by the terms of
;; this license. You must not remove this notice, or any other, from this
;; software.
;;
;; File: cond.clj
;;
;; scgilardi (gmail)
;; 2 October 2008
(ns clojure.contrib.cond)
(defmacro cond-let
"Takes a binding-form and a set of test/expr pairs. Evaluates each test
one at a time. If a test returns logical true, cond-let evaluates and
returns expr with binding-form bound to the value of test and doesn't
evaluate any of the other tests or exprs. To provide a default value
either provide a literal that evaluates to logical true and is
binding-compatible with binding-form, or use :else as the test and don't
refer to any parts of binding-form in the expr. (cond-let binding-form)
returns nil."
[binding-form & clauses]
(when-let [[test expr & more] clauses]
(if (= test :else)
expr
`(if ~test
(let [~binding-form ~test] ~expr)
(cond-let ~binding-form ~@more)))))
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