+------------------------------------------------------------------------------+
| 				CS100                                          |
|		        Box Scope Diagram rules                                |
|		       Modified from Spring 2000                               |
|			   (work in progress)                                  |
+------------------------------------------------------------------------------+
| Key:                                                                         |
| + main bullet                                                                |
| - sub bullet                                                                 |
| @ Updated portions 11/13/2000						       |
| # Unfinished                                                                 |
+------------------------------------------------------------------------------+
  General:
    + the following boxes get drawn at CERTAIN points in the code
    + changes in later portions of code change the diagram
+------------------------------------------------------------------------------+
  Boxes:
*   + indicate the limit of SCOPE
*     - Scope refers to the visibility of a piece of code
*     - What the code can, and cannot, access/use
    + if the calling code cannot find the variable/method/object/class inside
      the current box, the calling code "looks" outside the current box
    + if the thing sought after is still not found, the calling code
      keeps looking at the outer boxes until there no more boxes
    + usually the search stops at the class box
    + the location in a certain box indicates an entity's scope
+------------------------------------------------------------------------------+
  Class:
    + every class gets a box
+------------------------------------------------------------------------------+
  Class variable:
    + gets a box inside the class box
    + values start off as zero (according to type)
    + if value changes, cross off the old value and write the new one nearby
+------------------------------------------------------------------------------+
  Class method:
    + gets a box inside the class box WHEN the method is activated
*   + write the method name and input argument variables above the method box
    + cross off the method when the activation ends
    + when a the method is called again write a new box for the method
      to the right 
*   + ultimately, you will not draw method boxes to improve clarity
+------------------------------------------------------------------------------+
  Object:
    + Draw a box inside the class when an object is created
    + the reference variable that refers to the object has an arrow drawn to the
      object box
*   + Delete this line: [cross off the object when it is destroyed]
*     Why? Most of the diagrams we'll have you draw won't correspond to
*     code that clearly indicates the death of an object.
#   + Cross off an object for the following conditions:......
+------------------------------------------------------------------------------+
  Instance variable:
    + gets a box inside the object box
    + values start off as zero (according to type)
    + if value changes, cross off the old value and write the new one nearby
+------------------------------------------------------------------------------+
  Instance method:
    + gets a box inside the object box WHEN the method is activated
*   + write the method name and input argument variables above the method box
    + cross off the method when the activation ends
    + when a the method is called again write a new box for the method
      to the right 
*   + ultimately, you will not draw method boxes to improve clarity
+------------------------------------------------------------------------------+
* Constructor:
*   + technically, follow the same rules of instance methods
*   + usually you will not include constructors to ease clarity
+------------------------------------------------------------------------------+
  Local variable:
    + gets a box inside a method
    + has unknown/undetermined values, so write a question mark (?) inside the
      local-variable box
    + the collection of variables inside the box for a method is called the
      ACTIVATION RECORD
    + cross off arrows of reference variables after method activation ends 
      (see Arrow, below)
+------------------------------------------------------------------------------+
* Arrow:
*   + Draw an arrow to connect a reference variable to an object when an
*     assignment occurs
*   + Local variables might also contain references, so they may connect
*     to objects. Draw arrows unless instructed otherwise:
*     - for clarity, sometimes we will not draw these arrows for
*       variables inside methods that finish execution  
*     - methods which we occasionally ignore are setters and getters
*   + When a connection to an object is lost/terminates, draw an X on
*     the arrow -- the X indicates you are "crossing off" the arrow
#   + arrows point (to? from?) variable (to? from?) object
+------------------------------------------------------------------------------+
  Default values of class and instance variables are zeros:
*   + char:    ASCII Code 0  (ASCII code of 0 is something called NUL PROMPT)
    + int:     0
    + float:   0.0
    + double:  0.0
    + boolean: false
    + Object:  null
    + String:  null
@ What values go in the boxes?
@   + Give instance variables a default value
@   + If the variable has an initial assignment, [cross off zero and replace
@      with value (maybe better to say give the value and skip the zero?)]
+------------------------------------------------------------------------------+
* API:
*   + Builtin methods/variables/classes:
*     Do not draw boxes unless something your code does creates unique
*     objects modified by other portions of the code.
#   + Example: do not draw boxes for System.out.println
+------------------------------------------------------------------------------+
* Strings:
*   + Draw a class box called STRING CLASS
*   + Draw string literals inside the string-class box
*   + Arrows point directly to the string literals
+------------------------------------------------------------------------------+
# $args$:
# TBD
+------------------------------------------------------------------------------+
# Inheritance:
# TBD
+------------------------------------------------------------------------------+
@ Arrays:

+------------------------------------------------------------------------------+