Quiz   19 Sept 2013   Do all questions:

1)  Scanner

  write a regular expression for Thai names such as "ประภาส จงสถิตย์วัฒนา"

2)  Grammar

  Here are examples of the sentences in my "robotic" language:

  pick up the blue box
  put the box on top of the table
  clear the table
  where is the big red pyramid?

  Write a grammar to define this language

3)  Write a recursive program to expand "macro".  Given a parse-tree and a macro.  Substitute the macro call in the parse-tree.  Here is an example:

  main()
    a = b + c
    b = inc(b)

  macro inc(x)
    x + 1

The parse-tree for "main" is

(main (do (= a (+ b c)) (= b (macro inc b))))

(macro inc (x) (+ x 1))

To expand a macro, inc(b) is replace by (+ b 1). The b is binded to x and x + 1 is changed to b + 1.  Here is the output after expansion

(main (do (= a (+ b c)) (= b (+ b 1))))

You can write this program in a pseudo code.  Your function API is  expand(p1, p2)   where p1 is the main, p2 is the macro, it returns the new parse-tree.

  
Hand in to Khun Su at the office by 4pm on Monday 23 Sept.