tasks a-s

Task/Run-length-encoding/Icon/run-length-encoding.icon

@@ -0,0 +1,27 @@
+procedure main(arglist)
+
+   s := "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"
+
+   write(" s=",image(s))
+   write("s1=",image(s1 := rle_encode(s)))
+   write("s2=",image(s2 := rle_decode(s1)))
+
+   if s ~== s2 then write("Encode/Decode problem.")
+               else write("Encode/Decode worked.")
+end
+
+procedure rle_encode(s)
+   es := ""
+   s ? while c := move(1) do es ||:= *(move(-1),tab(many(c))) || c
+   return es
+end
+
+procedure rle_decode(es)
+   s := ""
+   es ? while s ||:= Repl(tab(many(&digits)),move(1))
+   return s
+end
+
+procedure Repl(n, c)
+    return repl(c,n)
+end