diff options
| -rw-r--r-- | build.xml | 1 | ||||
| -rw-r--r-- | src/clojure/contrib/core.clj | 40 | ||||
| -rw-r--r-- | src/clojure/contrib/core/tests.clj | 36 |
3 files changed, 77 insertions, 0 deletions
@@ -83,6 +83,7 @@ <arg value="clojure.contrib.command-line"/> <arg value="clojure.contrib.complex-numbers"/> <arg value="clojure.contrib.cond"/> + <arg value="clojure.contrib.core"/> <arg value="clojure.contrib.def"/> <arg value="clojure.contrib.duck-streams"/> <arg value="clojure.contrib.except"/> diff --git a/src/clojure/contrib/core.clj b/src/clojure/contrib/core.clj new file mode 100644 index 00000000..6ce8c6e0 --- /dev/null +++ b/src/clojure/contrib/core.clj @@ -0,0 +1,40 @@ +; Copyright (c) Laurent Petit and others, March 2009. All rights reserved. + +; The use and distribution terms for this software are covered by the +; Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php) +; which can be found in the file epl-v10.html 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. + +;; functions/macros variants of the ones that can be found in clojure.core + +;; note to other contrib members: feel free to add to this lib + +(ns clojure.contrib.core + (:use clojure.contrib.def)) + +(defmacro- defnilsafe [docstring non-safe-name nil-safe-name] + `(defmacro ~nil-safe-name ~docstring + {:arglists '([~'x ~'form] [~'x ~'form ~'& ~'forms])} + ([x# form#] + `(let [~'i# ~x#] (when-not (nil? ~'i#) (~'~non-safe-name ~'i# ~form#)))) + ([x# form# & more#] + `(~'~nil-safe-name (~'~nil-safe-name ~x# ~form#) ~@more#)))) + +(defnilsafe + "Same as clojure.core/-> but returns nil as soon as the threaded value is nil itself (thus short-circuiting any pending computation). + Examples : + (-?> \"foo\" .toUpperCase (.substring 1)) returns \"OO\" + (-?> nil .toUpperCase (.substring 1)) returns nil + " + -> -?>) + +(defnilsafe + "Same as clojure.core/.. but returns nil as soon as the threaded value is nil itself (thus short-circuiting any pending computation). + Examples : + (.?. \"foo\" .toUpperCase (.substring 1)) returns \"OO\" + (.?. nil .toUpperCase (.substring 1)) returns nil + " + .. .?.) diff --git a/src/clojure/contrib/core/tests.clj b/src/clojure/contrib/core/tests.clj new file mode 100644 index 00000000..ddc79dc7 --- /dev/null +++ b/src/clojure/contrib/core/tests.clj @@ -0,0 +1,36 @@ +; Copyright (c) Laurent Petit, March 2009. All rights reserved. + +; The use and distribution terms for this software are covered by the +; Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php) +; which can be found in the file epl-v10.html 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. + +;; test namespace for clojure.contrib.core + +;; note to other contrib members: feel free to add to this lib + +(ns clojure.contrib.core.tests + (:use clojure.contrib.test-is) + (:use clojure.contrib.core)) + +(deftest test-classic-versions + (testing "Classic -> throws NPE if passed nil" + (is (thrown? NullPointerException (-> nil .toString))) + (is (thrown? NullPointerException (-> "foo" seq next next next .toString)))) + (testing "Classic .. throws NPE if one of the intermediate threaded values is nil" + (is (thrown? NullPointerException (.. nil toString))) + (is (thrown? NullPointerException (.. [nil] (get 0) toString))))) + +(deftest test-new-versions + (testing "Version -?> returns nil if passed nil" + (is (nil? (-?> nil .toString))) + (is (nil? (-?> "foo" seq next next next .toString)))) + (testing "Version -?> works well for some basic use cases" + (is (= (list \O \O) (-?> "foo" .toUpperCase rest)))) + (testing "Version .?. returns nil if one of the intermediate threaded values is nil" + (is (nil? (.?. nil toString))) + (is (nil? (.?. [nil] (get 0) toString))))) +
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