Data update

Task/Fibonacci-word/PascalABC.NET/fibonacci-word.pas

@@ -0,0 +1,37 @@
+function entropy(str: string): real;
+begin
+  //  ## return the entropy of a fibword string.
+  if str.length <= 1 then begin result := 0.0; exit end;
+  var strlen := str.length;
+  var count0 := str.where(c -> c = '0').count;
+  var count1 := strlen - count0;
+  result := -(count0 / strlen * log2(count0 / strlen) + count1 / strlen * log2(count1 / strlen))
+end;
+
+function fibword(): sequence of string;
+begin
+  //  ## Yield the successive fibwords.
+  var a := '1'.ToString;
+  var b := '0'.ToString;
+  yield a;
+  yield b;
+  while true do
+  begin
+    a := b + a;
+    swap(a, b);
+    yield b
+  end;
+end;
+
+begin
+  println(' n    length       entropy');
+  println('————————————————————————————————');
+  var n := 0;
+  foreach var str in fibword do
+  begin
+    n += 1;
+    write(n:2, str.length:10, entropy(str):18:14);
+    if n < 10 then writeln('  ', str) else writeln;
+    if n = 37 then break
+  end;
+end.