% Code of Figure 7.5, page 280 from
% Kenneth C. Louden, Programming Languages
% Principles and Practice 2nd Edition
% Copyright (C) Brooks-Cole/ITP, 2003
% NOTE: I have not checked this code
% against a CLU compiler

numcount = proc (s: string) returns (int);
  count: int = 0;
  for c: char in stringchars(s) do
    if numeric (c) then
      count := count + 1;
    end;
  end;
  return (count);
end numcount;

stringchars = iter (s: string) yields (char);
  index: int := 1;
  limit: int := string$size(s);
  while index <= limit do
    yield (string$fetch(s, index))
    index := index + 1;
  end;
end stringchars;