re-sub and re-gsub now accept replacement fns. Patch from Juergen Gmeiner.

2 files changed, 61 insertions, 6 deletions

diff --git a/src/clojure/contrib/str_utils.clj b/src/clojure/contrib/str_utils.clj
index f6a59002..74a5266e 100644
--- a/src/clojure/contrib/str_utils.clj
+++ b/src/clojure/contrib/str_utils.clj
@@ -43,17 +43,39 @@
            (list (.subSequence string prevend (.length string))))))
      0)))
 
-(defn re-gsub
+(defn re-gsub 
   "Replaces all instances of 'pattern' in 'string' with
-  'replacement'.  Like Ruby's 'String#gsub'."
-  [#^Pattern regex replacement #^String string]
-  (.. regex (matcher string) (replaceAll replacement)))
+  'replacement'.  Like Ruby's 'String#gsub'.
+  
+  If (ifn? replacment) is true, the replacement is called with the
+  match.
+  "
+  [#^java.util.regex.Pattern regex replacement #^String string]
+  (if (ifn? replacement)
+    (let [parts (vec (re-partition regex string))]
+      (apply str
+             (reduce (fn [parts match-idx]
+                       (update-in parts [match-idx] replacement))
+                     parts (range 1 (count parts) 2))))
+    (.. regex (matcher string) (replaceAll replacement))))
 
 (defn re-sub
   "Replaces the first instance of 'pattern' in 'string' with
-  'replacement'.  Like Ruby's 'String#sub'."
+  'replacement'.  Like Ruby's 'String#sub'.
+  
+  If (ifn? replacement) is true, the replacement is called with
+  the match.
+  "
   [#^Pattern regex replacement #^String string]
-  (.. regex (matcher string) (replaceFirst replacement)))
+  (if (ifn? replacement)
+    (let [m (re-matcher regex string)]
+      (if (.find m)
+        (str (.subSequence string 0 (.start m))
+             (replacement (re-groups m))
+             (.subSequence string (.end m) (.length string)))
+        string))
+    (.. regex (matcher string) (replaceFirst replacement))))
+
 
 (defn str-join
   "Returns a string of all elements in 'sequence', separated by
diff --git a/src/clojure/contrib/test_contrib/str_utils.clj b/src/clojure/contrib/test_contrib/str_utils.clj
new file mode 100644
index 00000000..812821dc
--- /dev/null
+++ b/src/clojure/contrib/test_contrib/str_utils.clj
@@ -0,0 +1,33 @@
+(ns clojure.contrib.test-contrib.str-utils
+    (:use clojure.contrib.test-is
+          clojure.contrib.str-utils))
+
+
+(deftest test-re-gsub
+  (let [re #"\%([0-9a-fA-F]{2})"
+        replacement (fn [match] 
+                      (char (Integer/parseInt 
+                              (match 1) 16)))]
+    (is (= (re-gsub re replacement "") ""))
+    (is (= (re-gsub re replacement "%20") " "))
+    (is (= (re-gsub re replacement "x%20") "x "))
+    (is (= (re-gsub re replacement "x%20%0a") "x \n"))
+    (is (= (re-gsub re replacement "x%20y") "x y"))
+    (is (= (re-gsub re "?" "") ""))
+    (is (= (re-gsub re "?" "%21") "?"))
+    (is (= (re-gsub re "?" "x%22") "x?"))
+    (is (= (re-gsub re "?" "x%23y") "x?y"))))
+
+(deftest test-re-sub
+  (let [re #"\%([0-9a-fA-F]{2})"
+        replacement (fn [match] 
+                      (char (Integer/parseInt 
+                              (match 1) 16)))]
+    (is (= (re-sub re replacement "") ""))
+    (is (= (re-sub re replacement "%20") " "))
+    (is (= (re-sub re replacement "x%20%20") "x %20"))
+    (is (= (re-sub re replacement "x%20y") "x y"))
+    (is (= (re-sub re "?" "") ""))
+    (is (= (re-sub re "?" "%21") "?"))
+    (is (= (re-sub re "?" "x%22%25") "x?%25"))
+    (is (= (re-gsub re "?" "x%23y") "x?y"))))