Time for an 2014 update…

Task/Generic-swap/AWK/generic-swap.awk

@@ -0,0 +1,25 @@
+# syntax: GAWK -f GENERIC_SWAP.AWK
+BEGIN {
+    printf("%s version %s\n",ARGV[0],PROCINFO["version"])
+    foo = 1
+    bar = "a"
+    printf("\n%s %s\n",foo,bar)
+    rc = swap("foo","bar") # ok
+    printf("%s %s %s\n",foo,bar,rc?"ok":"ng")
+    printf("\n%s %s\n",foo,bar)
+    rc = swap("FOO","BAR") # ng
+    printf("%s %s %s\n",foo,bar,rc?"ok":"ng")
+    exit(0)
+}
+function swap(a1,a2,  tmp) { # strings or numbers only; no arrays
+    if (a1 in SYMTAB && a2 in SYMTAB) {
+      if (isarray(SYMTAB[a1]) || isarray(SYMTAB[a2])) {
+        return(0)
+      }
+      tmp = SYMTAB[a1]
+      SYMTAB[a1] = SYMTAB[a2]
+      SYMTAB[a2] = tmp
+      return(1)
+    }
+    return(0)
+}

Task/Generic-swap/Julia/generic-swap.julia

@@ -0,0 +1 @@
+a, b = b, a

Task/Generic-swap/Nimrod/generic-swap.nimrod

@@ -0,0 +1 @@
+swap(a, b)