Time for an 2014 update…

Task/Combinations/D/combinations-1.d

@@ -1,15 +1,13 @@
-import std.stdio;
-
 T[][] comb(T)(in T[] arr, in int k) pure nothrow {
     if (k == 0) return [[]];
     typeof(return) result;
-    foreach (i, x; arr)
+    foreach (immutable i, immutable x; arr)
         foreach (suffix; arr[i + 1 .. $].comb(k - 1))
             result ~= x ~ suffix;
     return result;
 }
 
 void main() {
-    //import std.stdio: writeln;
-    [0, 1, 2, 3].comb(2).writeln();
+    import std.stdio;
+    [0, 1, 2, 3].comb(2).writeln;
 }

Task/Combinations/D/combinations-2.d

@@ -1,13 +1,12 @@
 import std.stdio, std.algorithm, std.range;
 
-T[][] comb(T)(in T[] s, in int m) /*pure nothrow*/ {
+T[][] comb(T)(in T[] s, in int m) /*pure*/ nothrow {
   if (!m) return [[]];
   if (s.empty) return [];
-  return s[1 .. $].comb(m - 1).map!(x => s[0] ~ x)().array() ~
+  return s[1 .. $].comb(m - 1).map!(x => s[0] ~ x).array ~
          s[1 .. $].comb(m);
 }
 
 void main() {
-    //import std.stdio: writeln;
-    iota(4).array().comb(2).writeln();
+    4.iota.array.comb(2).writeln;
 }

Task/Combinations/Elena/combinations.elena

@@ -0,0 +1,25 @@
+#define system.
+#define system'routines.
+#define extensions.
+#define extensions'routines.
+
+#symbol M = 3.
+#symbol N = 5.
+
+// --- Numbers ---
+
+#symbol numbers = (:anN)
+[
+    arrayControl new &length:anN &each: anIndex [ Integer new:(anIndex + 1) ]
+].
+
+// --- Program ---
+
+#symbol program =
+[
+    #var aNumbers := numbers:N.
+    controlEx for:(Combinator new:(arrayControl new &length:M &each: i [ aNumbers ])) &do: aRow
+    [
+        consoleEx writeLine:aRow.
+    ].
+].

Task/Combinations/Julia/combinations.julia

@@ -1,3 +1,3 @@
-for i in @task combinations(1:5,3)
-println(i)
+for i in combinations(1:5,3)
+    print(i')
 end