****************
ENTER NAMED CONSTANT - DONE
****************
last modified: 12-12-11

The user can declare named constants, and then use them in the body
of their function.

STATUS: DONE
FIRST PASSED: 12-06-11 (they completed earlier, though, I think -- took
              me a while to get to completing acceptance test for
	      this)
acceptance tests last attempted: 12-12-11
acceptance tests last passed:    12-12-11

------------------
acceptance test 1
------------------
user can declare a named constant, and then use it in a function

(make sure that /Users/smtuttle/480xp-tests/const-exs exists, and
is empty -- pre-4 should have emptied it;)

(if necessary:
1. run:
   python3 theGui.pyw

2. Click "Change directory" and navigate to the following
   directory:
   /Users/smtuttle/480xp-tests/const-exs
   ...and click "Choose".
)

3. Click "New" to create a new function circ_area -- which, wow,
   happens to use a named constant!

circ_area

circ_area: double -> double

<make sure this is multiple-lines!!>   
expects the radius of a circle, and produces the area
of a circle with that radius

double circ_area(double radius)

const double PI = 3.14159;

circ_area(10) == 314.159
circ_area(1) == 3.14159
   
{
    return PI * (radius * radius);
}

4. Click "Compile, Test and Save";
   See if compiles and if all tests pass;

5. See if can now run an expression using this function:
   *   move windows around so you have the Helper++ window
   *   now, in Helper++:
       *   click circ_area's checkbox on the right;

       *   enter the expression:

           circ_area(10)

           ...and click Execute.

   should give result: 314.159

6. See if can now run an expression using this function that happens
   to include the named constant
       *    slightly crueler, but OUGHT to work if implemented
            as desired; if this passes, though, it is an indication
            that a function using this function (as the expression's
	    main is) can use such a named constant, too?

            enter the expression:

            circ_area(PI)

           ...and click Execute.

   should give approximate result 31.0062

LAST TESTED: 12-12-11
LAST PASSED: 12-12-11