CSE 305 Programming Languages Fall, 2003
Professor Shapiro
Homework 3
Maximum Points: 12
Due 12:01 am, Thursday, September 25, 2003

Copy this file to a text file named hw3.txt, edit into it your
answers, and submit the file via the submit program by the deadline
given above.

1. (3) Using the "Higher-level, low-level language" for operational
semantics, give the operational semantics of Java's do statement,

	    do statement while (expression);

2. (3) Using the "Lower-level, low-level language" for operational
semantics, give the operational semantics of the Java statement,

	   x = y + z * w;

3. (3) Using the "Lower-level, low-level language" for operational
semantics, give the operational semantics of the Java statement,

	   j = i++ + i;

4. (3) As the text says, "Perl's dynamic scoping is unusual---in fact it
is not exactly like that discussed in this section, although the
semantics are often that of traditional dynamic scoping" [p. 218].
What is printed by the following Perl program:

     #! /util/bin/perl

     $x = 1;
     $y = 2;
     
     sub inner {
       # Print the nonlocals $x and $y
       print "x = $x, y = $y\n";
       }
     
     sub outer {
       # The formal parameter is implicitly the array @_
       #   so the first argument is assigned to @_[0]
       #   and the second argument is assigned to @_[1]
     
       # make $x have static scope
       my $x = @_[0];
     
       # make $y have dynamic scope
       local $y = @_[1];
     
       # Now call the subroutine inner
       inner;
       }
     
     # Call the subroutine outer with arguments 3 and 4
     outer(3, 4);