How to count all the words in a textfile with multiple space characters

Question

I am trying to write a procedure that counts all the words in a text file in Pascal. I want it to handle multiple space characters, but I have no idea how to do it.

I tried adding a boolean function Space to determine whether a character is a space and then do

while not eof(file) do
begin    
  read(file,char);
  words:=words+1;
  if Space(char) then
    while Space(char) do
      words:=words;

but that doesnt work, and basically just sums up my(probably bad) idea about how the procedure should look like. Any ideas?

Answer 1

Basically, as Tom outlines in his answer, you need a state machine with the two states In_A_Word and Not_In_A_Word and then count whenever your state changes from Not_In_A_Word to In_A_Word.

Something along the lines of (pseudo-code):

var
  InWord: Boolean;
  Ch: Char;
begin
  InWord := False;
  while not eof(file) do begin    
    read(file, Ch);
    if Ch in ['A'..'Z', 'a'..'z'] then begin
      if not InWord then begin
        InWord := True;
        Words := Words + 1;
      end;
    end else
      InWord := False
  end;
end;