Dot Plot Version Three
Version Three
Added a getToken function that returns the next token. Use this
instead of using a loop to read lines in the parse procedure. The
reason for this is that it means that the source of tokens can be
hidden from the parse function (parse is less and less the correct
name but never mind). This means that we can supply tokens from a
stream of files or anything else we like. The getToken function will
call in turn a getLine function which in its turn calls getFile. each
has a single argument to hold the returned token, line or file and
returns true as the function value if the call succeeds or false if
there are no more tokens, lines or files.
