adding the key lookup procedure

diff --git a/src/sicp/ch2_3.clj b/src/sicp/ch2_3.clj
index a69973c95cfd54d55745294c714f8d1db412d4cf..55ef8adbb5c3631bcff8497c5cba84bf278ac2c1 100644 (file)
--- a/src/sicp/ch2_3.clj
+++ b/src/sicp/ch2_3.clj
@@ -136,3 +136,9 @@
                                      (left-branch set)
                                      (adjoin-set x (right-branch set)))))
 
+
+;;; key lookup
+(defn lookup [given-key set-of-records]
+  (cond (empty? set-of-records) false
+        (equal? given-key (key (first set-of-records))) (first set-of-records)
+        :else (lookup given-key (rest set-of-records))))
\ No newline at end of file