A note on parsing with string literals:

The tokenizer (or scanner) we have written for the assignment will recognize
<name> and <integer> constructs, but you will have to recognize float
and string literals and comments using the following grammar rules:

<numWDecimal> --> <integer> . <integer>
<stringLiteral> --> " <tokenseq1> "
<comment> --> /* <tokenseq2> */

(where <tokenseq1> is a sequence of non-" tokens returned by the
scanner and <tokenseq2> is a sequence of non-* and non-/ tokens
returned by the scanner).

Because we have to input the program to be parsed to the scanner as a string
(by surrounding it with " marks), a string constant within the 
input program must be delimited (on input) by 2 double quote marks.
That is, typing 

?- tokenize(A, "X = ""this is a string literal"" ",Z).

produces the list

A = [X, =,'"',this,is,a,string,literal, '"']

in which you can recognize the string literal using the grammar rule
above.  Similarly, if you use a quote mark inside your string constant
it must be input as 2 double quote marks.  (Let's not worry about
comments containing extra */ but just disallow them.)