Time for an 2014 update…

Task/Semordnilap/D/semordnilap-1.d

@@ -4,8 +4,8 @@ void main() {
     bool[string] seenWords;
     size_t pairCount = 0;
 
-    foreach (word; readText("unixdict.txt").toLower().splitter()) {
-        auto drow = word.dup.reverse;
+    foreach (const word; readText("unixdict.txt").toLower.splitter) {
+        const drow = word.dup.reverse; // Deprecated.
         if (drow in seenWords) {
             if (pairCount++ < 5)
                 writeln(word, " ", drow);

Task/Semordnilap/D/semordnilap-2.d

@@ -0,0 +1,9 @@
+void main() {
+    import std.stdio, std.file, std.algorithm, std.string, std.range;
+
+    auto words = "unixdict.txt".readText.split.zip(0.repeat).assocArray;
+    auto pairs = zip(words.byKey, words.byKey.map!(w => w.dup.reverse))
+                 .filter!(wr => wr[0] < wr[1] && wr[1] in words)
+                 .zip(0.repeat).assocArray;
+    writeln(pairs.length, "\n", pairs.byKey.take(5));
+}

Task/Semordnilap/PicoLisp/semordnilap.l

@@ -0,0 +1,7 @@
+(let Semordnilap
+   (mapcon
+      '((Lst)
+         (when (member (reverse (car Lst)) (cdr Lst))
+            (cons (pack (car Lst))) ) )
+      (make (in "unixdict.txt" (while (line) (link @)))) )
+   (println (length Semordnilap) (head 5 Semordnilap)) )