Mercurial > lasercutter
comparison src/clojure/contrib/cond.clj @ 10:ef7dbbd6452c
added clojure source goodness
| author | Robert McIntyre <rlm@mit.edu> |
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| date | Sat, 21 Aug 2010 06:25:44 -0400 |
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| 9:35cf337adfcf | 10:ef7dbbd6452c |
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| 1 ;; Copyright (c) Stephen C. Gilardi. All rights reserved. The use and | |
| 2 ;; distribution terms for this software are covered by the Eclipse Public | |
| 3 ;; License 1.0 (http://opensource.org/licenses/eclipse-1.0.php) which can | |
| 4 ;; be found in the file epl-v10.html at the root of this distribution. By | |
| 5 ;; using this software in any fashion, you are agreeing to be bound by the | |
| 6 ;; terms of this license. You must not remove this notice, or any other, | |
| 7 ;; from this software. | |
| 8 ;; | |
| 9 ;; File: cond.clj | |
| 10 ;; | |
| 11 ;; scgilardi (gmail) | |
| 12 ;; 2 October 2008 | |
| 13 | |
| 14 (ns ^{:author "Stephen C. Gilardi" | |
| 15 :doc "Extensions to the basic cond function."} | |
| 16 clojure.contrib.cond) | |
| 17 | |
| 18 (defmacro cond-let | |
| 19 "Takes a binding-form and a set of test/expr pairs. Evaluates each test | |
| 20 one at a time. If a test returns logical true, cond-let evaluates and | |
| 21 returns expr with binding-form bound to the value of test and doesn't | |
| 22 evaluate any of the other tests or exprs. To provide a default value | |
| 23 either provide a literal that evaluates to logical true and is | |
| 24 binding-compatible with binding-form, or use :else as the test and don't | |
| 25 refer to any parts of binding-form in the expr. (cond-let binding-form) | |
| 26 returns nil." | |
| 27 [bindings & clauses] | |
| 28 (let [binding (first bindings)] | |
| 29 (when-let [[test expr & more] clauses] | |
| 30 (if (= test :else) | |
| 31 expr | |
| 32 `(if-let [~binding ~test] | |
| 33 ~expr | |
| 34 (cond-let ~bindings ~@more)))))) |