1 files changed, 21 insertions, 0 deletions
diff --git a/src/clojure/contrib/expect/util.clj b/src/clojure/contrib/expect/util.clj
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+++ b/src/clojure/contrib/expect/util.clj
@@ -0,0 +1,21 @@
+(ns clojure.contrib.expect.util
+  (:use clojure.contrib.seq-utils))
+
+(defmacro assert-args [fnname & pairs]
+  `(do (when-not ~(first pairs)
+         (throw (IllegalArgumentException.
+                  ~(str fnname " requires " (second pairs)))))
+     ~(let [more (nnext pairs)]
+        (when more
+          (list* `assert-args fnname more)))))
+
+(defn indexes
+  "Returns a lazy sequence of the indexes in coll for which the element
+is equal to v."
+  [coll v]
+  (map #(first %) (filter (fn [[i el]] (= el v)) (indexed coll))))
+
+(defn index-of
+  "Returns the first index of value v in the collection or nil."
+  [coll v]
+  (first (indexes coll v)))